Hawai‘i Low Land Mesic Forest Restoration Manual (May 2015)

written by:
Richard L. Quinn, ASLA
May 2015
PRODUCED BY:
ECOSYSTEM RESTORATION SERIES
HAWAI’I LOW LAND MESIC FOREST
RESTORATION MANUAL

NOTE:
This manual has been produced as part two of a
series on Hawaiian native ecosystem restoration.
Part one of this series is the “Hawai’i Native Plant
Microbiome Manual”.
PRODUCED BY: HHF Planners
address: HHF Planners
733 Bishop Street, suite 2590
Honolulu, Hawaii 96813
phone: 1-808-545-2055
web: www.hhf.com
Updated May 2015.
This document was ﬁrst published in October
2014.

HAWAI’I DRYLAND FOREST PLANTING MANUAL
PLANTS AND PLANTING METHODS 5
NATIVE FOREST RESTORATION
The Hawai‘i native lowland dry and mesic forests have largely disappeared over the
course of Polynesian and subsequent migration of the islands. With a comprehensive
understanding of the complexities of ecosystem dynamics, the restoration of
sustainable and vital mesic forests can be achieved.
An additional excellent resource of information for Hawai‘i native plant restoration
is: Ho‘ōlaI Ka Nahele: To Heal A Forest, Mesic Forest Restoration Guide for Hawaii. By Dan
Sailer
WHY RESTORATION OF HAWAII MESIC
FORESTS IS IMPORTANT
• Restoring the native ecosystem of lowland forests can help protect the biodiversity of
Hawai‘i’s special and unique plants and animals. The uniqueness of Hawai‘i’s native
plants and animals makes Hawai‘i different than other places, enhancing the sense of
community, culture, and quality of life for the human residents of these islands.
• The careful selection and out planting of speciﬁc native plants in any restoration
activity can help increase seed and propagation material for other restoration efforts
and aid in research in out planting methodology
• Restoring the native ecosystem can be of beneﬁt to Native Hawaiian cultural
practitioners and others that gather native species for cultural, research, or
educational purposes.
• The restoration of a native Hawaiian ecosystem with its associated soil ecology can
help to increase carbon sequestration. Degraded soils and invasive plants can greatly
reduce the carbon storage capability of native soils.
• Restoring an ecological balance that helps protect the unique biodiversity of native
Hawaiian vegetation also helps protect ground water resources and ocean resources.

6 PLANTS AND PLANTING METHODS HHF Planners Inc - Dec 2014
THE CHALLENGE
The vast disturbance and deforestation of the native forests in lowland areas of the
Hawaiian Islands has resulted in a feed-back cycle of change with the end result of
an almost irreversible state where the native forest vegetation simply cannot recover
without heroic measures. The current state now favors non-native vegetation. Simply
re-planting native plants is not necessarily enough to overcome the current status.
The availability of natural resources and environmental conditions (such as the soil
biota) may have shifted to such an extent that conditions are not adequate for forest
regeneration, even with re-vegetation by planting. A reversion to the non-native
condition will occur rapidly, as that is the most recent stable condition (this is the
theory of“hysteresis”).
CREATING RESTORATION “KIPUKA” IN A SEA OF INVASIVES
Creating small dense“islands”of diverse native plantings in highly disturbed
landscapes can be an efficient and manageable way to re-establish a native forest
with a native soil ecology. An ecosystem analogy is the hawaiian concept of a kipuka,
which is an area of forest that has been spared by parting lava, that acts as a refuge
for plants and animals to repopulate the forest. Within restoration kipukas, as tree
canopies mature, expansion and merging of planting islands becomes practical.
Seed is more available. Regeneration and self propagation help expand the kipuka.
Soil ecology will be restored more quickly in concentrated native plantings, which
can then be used to colonize adjoining new plantings as the restoration“islands”are
expanded. Studies have shown that providing greater diversity of plant species in
the same area can greatly increase the quantity and quality of soil biota. The increase
in plant diversity increased soil micro-organism diversity, which helps support other
components of the soil food web, to the benefit of individual plant species within
the mix.
Native Hawaiian plants have evolved to depend on mycorrhizal fungus to help
provide nutrients, water, and disease and insect resistance. Native plants need poor
soil to form mycorrhizal associations. Many non-native and invasive plants change
soil ecology through rapid nutrient cycling that pumps nitrogen and phosphorus
back into the soil quickly. Leaf litter decomposes more rapidly, leaving bare soil
surfaces that erode more easily. Conversely, many native plants have a much slower
decomposition of leaf litter, which allows for the development of a humus layer and
The Environmental Feedbacks affecting Restoration Success
• Water Table changes
• Erosion / water shed run-off changes
• Local weather / rainfall shifts due to deforestation
• Ground water salinity changes
• Fire Frequency
• Micro-climate changes
• Nutrient cycling and nutrient storage changes
• Soil biota changes / soil chemistry / soil temperature

EXAMPLE FOREST RESTORATION UNIT
Figure 16: Example design for a forest restoration “island”.

soil rhizosphere that is beneficial to the micro-organisms
that native plants need, absorbs and holds water better,
and is less subject to erosion. By removing invasive plants
from small focused areas within highly disturbed and
invaded areas, pockets of soil with a more native ecological
composition can be created, with greater resistance to
invasive weeds.
DRY FOREST RESTORATION “ISLAND” COMPONENTS
1. Modular design: The modular restoration units do
not represent an exact landscape layout, but rather are
diagrammatic, and are meant to represent a quantified
scope of work that can be contracted. The actual layout
and exact placement of materials should be field
adjusted, under the direction of the wildlife manager,
DOFAW botanist, or project landscape architect.
2. Clearing: The entire restoration unit (about 1/10th
acre area) should be cleared of weed trees, such as
Java Plum, African Tulip, and Gun Powder trees. Other
existing vegetation should remain if outside of the
planting“island”boundary. Only the planting“island”
within the restoration unit should be cleared of all
existing vegetation, except significant trees that are
deemed useful as“nurse”trees (non-native trees that
can provide useful shade and wind protection for
understory native plants). These trees should be tagged
for preservation.
3. Bio-Sock: The use of a biodegradable“bio-sock”
(landscape fabric tube) filled with coarse mulch and
pinned to the soil creates a barrier on the down slope
side of the planting island that reduces erosion, helps
retain leaf litter and mulch around plantings, reduces
weeds, retains moisture, helps to protect temporary
drip irrigation tubing, and provides a matrix for the
growth of soil fungus and micro-organisms. The bio-
sock will provide a persistent organic layer near the
base of native trees, mimicking the function of a native
soil humus layer or rotting log.
4.
5. Weed Barrier Banding: Use a strip of weed barrier
cloth to define the up-slope boundary of the restoration
island. A 3 ft width of woven weed barrier cloth, secured
with pins, will help to provide a clear maintenance strip
and access pathway around the top and sides of the
planting area. By eliminating a band of vegetation on
the up-slope side, there is less root competition and an
increase in rain water availability to the seedling native
plants below. Weed barrier cloth should not be used
within the planting island, with plantings placed within
cut outs in the cloth, as it can be difficult and messy
to remove later, will separate leaf litter from the soil
rhizosphere, and can inadvertently shed rainwater away
from the base of plants. Leaf litter and debris can build
up on top of weed barrier cloth, actually encouraging
weeds to grow with roots penetrating through the
top of the weed cloth. But when used in a strip at the
upper slope of a planting island, a narrow band of
weed cloth is likely to be flushed of any surface build-
up of soil or litter with water run-off into the plantings
below, or can be easily cleared of debris. A banding of
weed barrier cloth will help reduce soil compaction,
retain moisture, reduce competitive weeds and grasses,
and reduce damage from weed control operations
(mowers and string trimmers). A band of weed control
fabric that defines the up-slope boundary of a planting
area can be easily shifted later to reveal a cleared area
ready for additional plantings for easy expansion of the
restoration“island”area.
6. Mulch: The use of an ample layer of mulch around
restoration out-plantings can have important
benefits, but should be done with an understanding
of its consequences. The benefits of mulch are well
established, as it reduced weeds, reduces erosion, helps
retain soil moisture, reduces soil compaction, provides
slow release organic nutrients, and helps to provide a
matrix for important soil micro-organisms.
The primary negative aspect of using mulch is that it can
reduce water absorption into the root zone from a light
rainfall. A thick layer of mulch can become hydro-phobic
once it has dried out, which results in water running off
and not penetrating to the soil below. Conversely, if the
mulch layer highly composted and fine, and is kept moist
for an extended period by seasonal rainfall or irrigation, it
can encourage a thin surface growth of plant roots into the
mulch that can then quickly dry out when water is reduced,
causing plant stress.

Another negative aspect that is often sighted is that
mulch can rob a soil of nitrogen as it decomposes. This
is most likely not an issue for coarse mulch used on
surface applications. Also, a reduction of soil nitrogen by
decomposing mulch might actually be beneficial to native
plants, as it would encourage plant associations with
mycorrhizal fungus for nutrient uptake, while reducing
weed growth.
KIPUKA PLANTING “ISLAND” CONCEPT
Figure 17: Bio-remediation Sketch

With thoughtful use, the benefits of mulch can out-weight
the negatives. Use a coarse mulch of shredded wood. Do
not use mulch from leaf or grass clippings. Fine mulch is
more likely to shed water, to wash out in heavy rain, and to
decompose quickly. Do not mix mulch into the soil as an
amendment, but only use as a top dressing. It is important
in dry and semi-dry locations when using mulch in
restoration efforts to provide supplemental deep watering
(such as with drip irrigation) to seedling plants.
7. Fertilizers and Herbicides: Do not use any fertilizers
or insecticides on ecosystem restoration plantings
unless under the direction of the project botanists
or landscape architect. Chemicals can reduce the
colonization of important soil micro-organisms and
plant endophytes. Once cleared and planted, the use
of herbicides within the restoration islands should be
limited to very targeted applications and only with the
use of approved herbicides. The marsh is a sensitive
habitat and there are restrictions on the use of certain
chemicals.
8. Activation of Soil Ecology: A goal of restoration
is to replicate essential soil micro-biology and the
development of a native soil rhizosphere. Planting
composition and species selection should be designed
to encourage colonization of mycorrhizae and
useful plant bacteria. Some native plant species are
more readily colonized by mycorrhizal fungus than
other species. Some native plants, such as Koa, can
help enhance the presence of mycorrhizal fungus
through a synergistic relationship with nitrogen fixing
rhizobacteria. Some native shrubs and ferns, such as
Bidens spp or Dianella spp, can be used to readily
inoculate a planting area with native micro biota.
9. EROSION CONTROL: An important strategy to
reducing the potential for erosion during restoration
plantings is to minimize soil tilling. This strategy will
also reduce invasive weed growth. Only dig and turn
soil in planting holes just wide enough for the plants,
and don’t turn soil beyond the planting holes. Minimize
soil grubbing during clearing operations. Use mulch
in sloped areas to help control erosion, but avoid use
in main pathways near the edges of streams or open
water, as mulch can cause detrimental organic loading
of wetlands if washed down by heavy runoff. Even soil
that is very compacted will regain a natural tilth once
covered with mulch or leaf litter, making the physical
turning of soil unnecessary.
Timing clearing and grubbing activities during the dry
season will help to minimize erosion. Construction activities
should be stopped during rain events.
Install perimeter sediment controls such as compostable
filter socks and silt curtains prior to any earth-disturbing
activities. Biodegradable Filter Socks placed parallel to
slopes can help retain leaf litter, benefiting weed control
and the bio-activation of soil, in addition to erosion control
benefits.

HAWAI’I DRYLAND FOREST - PLANTING GUIDE
Planting methods for restoration of dryland and lower mesic forests in Hawai‘i
typically involve the use of nursery grown material, often in dibble tubes, outplanted
with little to no follow-up watering after the initial planting, but heavily maintained
by occasional weeding until establishment. Little regard has been given to the soil
ecology and the re-establishment of a native soil biology essential to native Hawaiian
plants when out planting in heavily disturbed or invaded sites.
Planting methods that reduce the need for follow up weeding and maintenance
should be explored for the restoration of Dryland forests in Hawai’i. Maintenance
methods that encourage natural re-generation, plant succession, and the ready
expansion of focused areas of restoration, should be utilized.
Plant material should be propagated from material of known linage, and ideally
sourced from the general area of outplanting. As much as practical, plant material
to be used at specific restoration sites should be direct descendants of wild plants
from the same general area. However, for some species, an argument could be made
that genetic health and vigor of plants of limited local population size might benefit
from wider genetic material from other locations. Also, some plant species may have
been have had a much wider range than currenlty indicated. Consult with a qualified
native plant biologist before sourcing material from off island or locations remote
from the restoration site.
PLANT PROPAGATION
For restoration of native forests, for most species, plants propagated by seed are
better than cuttings. Seed grown plants insure better genetic diversity and health.
Due to practical limitations of quantity needed, availability of seed, and time to
produce plants, sometimes the only practical option is growing plants from cuttings.
As much as possible, cuttings for any specific outplanting effort should come
from seed grown“mother”plants. In some species, growing plants from cuttings
from a source plant that itself came from a cutting, such that the outplanted plant
is a“cutting of a cutting of a cutting .......”, can result in a weakened plant that has
accumulated viruses and random genetic mutations with each generation removed
from the seed grown mother plant. Similarly, with some species, the perpetual
self pollination of cloned plants can also eventually genetically weaken a plant
population that is consistently propagated from the self pollinated seed of identical
clones. Lack of genetic diversity can make a plant population more susceptible to
environmental stresses.
SEED BANK THEORY
Wet land areas can be a source of great information on the composition of historic
plant populations, through pollen analysis, but also actual seed can sometimes be
found. Wetland areas can have undergone siltation over the last two hundred years
or so, with the potential of layers of latent seed remaining buried in the silt that may
actually still be viable and can germinate once exposed. This might enable the return
of historic plant populations that were adjacent to marsh areas.

Using a post hole digger, soil can be excavated from early layers in wet land areas
and spread over flats in a greenhouse to see what germinates.
DIRECT SEEDING
If sufficiently large enough quantities of viable seed are available from nearby
sources, they can be sown into the soil within the planting zone to enhance the
diversity of plants that might not otherwise be available in quantity as nursery grown
material. Plants grown on site by seed can be relocated to other areas on site to
augment nursery grown material. Seeds should be planted in groups in identifiable
locations such that as they germinate, they can be easily marked and protected from
maintenance activities until they can stand out on their own or be relocated.
Consider using the following as seeded plants:
• Santalum spp. (‘iliahi)
• Hibiscus spp.
• Sesbania spp. (‘Ōhai)
• Dodonaea viscosa (‘A’ali’i)
• Acacia koa
• Sapindus oahuensis (Lonomea)
• Loulu Palm
One technique is to place seed into containerized plants of other species at time
of out-planting so that the nursery potting mix becomes the planting matrix for a
different plant that will get watered and weed controlled as a matter of course. For
example, koa seed could be placed into the plantings of‘ōhai. at the time of out-
planting. The‘ohai is often a short lived plant. As the koa tree grows out by seed, the
ohai will fade, but the rhizobial bacteria of the ohai will migrate to the Koa and help
with its development. The leaf litter from the‘ōhai will help to establish mycorrhiza
at the base of the koa seedling and provide pre-colonization of mycorrhizal fungus.
Seeds of Loulu palm can be placed directly into the root ball of fern outplantings.
Fern root zones retain moisture well, and are highly mycorrhizal, and loulu palm
seeds can effectively germinate in fern plantings and still successfully compete and
extend leaf fronds beyond ferns to gain hold.
Seedlings will naturally become mycorrhizal very quickly if the soil is rich in
mycorrhizal hyphae.
NURSE CROP / COVER CROPS
A temporary cover can be used to help stabilize disturbed areas, or to protect
and nurture new plantings until maturity is sufficient to enable stability or to re-
establish a forest canopy. A“nurse crop”could include non-native but non-invasive
plants that remain in place until native plantings reach a level of maturity that will
enable survival (see HYBRID ECOSYSTEM below). Also, consider leaving non-native
weed trees and tall shrubs in place as girdled or poisoned trees, as a frame or trellis

for native vines such as‘āwikiwiki. This can be a means or providing a quick native
“canopy”. Existing plant massings adjacent to restoration plantings can help as wind
breaks, and can help improve microclimate conditions.
Cover crops can increase extraradical hyphal networks that can help colonize the
roots of the ﬁnal crop, while helping with weed control and wind control.
Plant cover crops, or “pioneer” species, that will be replaced by target species later.
• Dodonaea (a’ali’i) · Senna gaudichaudii (kolomona)
• Canavalia hawaiiensis (‘āwikiwiki) · Bidens sp. (ko’olau)
COMPANION PLANTING or CO-PLANTING
Planting two or more species together can have a synergistic effect that is beneficial
to a target plant or plants. This can allow for the out planting of younger, slower
growing plants, such as‘Ohi‘a lehua, to be planted at less than optimal size but be
protected till it can reach a sustainable size.
HYBRID ECOSYSTEM
Selective use of existing non-native plants within an ecosystem restoration site can
have the potential to aid in restoration efforts. Benefits can include:
• Reduction of aggressive sun loving weeds, such as grasses.
• Wind screening.
• Production of valuable leaf litter for soil building and mycorrhizae habitat.
• Reduced cost of ecosystem restoration.
• Reduced potential for erosion.
Plants to remain should be selected for their minimal aggressiveness. Interestingly,
research from the University of Hawai’i at Hilo has shown that many of the Hawaiian
“canoe”plants, those bought to Hawaii by Polynesian migration, are good candidates
for use in hybrid ecosystems. 36
Also, a selection of some more recently introduced
plants might be useful in a hybrid ecosystem approach as well. These include:
• Kukui
• Mango
• Monkeypod
• Breadfruit
• Mahogany
Invasive plants left in hybrid ecosystems should ideally be of species that have a slow
litter decomposition rate. Studies have shown that invasive plants typically have leaf
litter that decomposes faster than native leaf litter. This faster decomposition rate
can accelerate the decomposition of native litter, when mixed with the non-native
leaf litter. This accelerates the carbon cycling and soil respiration, increasing nutrient
cycling, which can be detrimental to native soil ecology and native plants, creating
advantageous conditions for the further establishment of non-native plants. This
creates a spiral that shifts the advantage for the re-establishment of noxious invasive
weeds. 4

BRADLEY METHOD OF NATIVE PLANT RESTORATION
Developed by ecologists in Australia, this system of restoration uses well established ecological principles to encourage
the regeneration of native forests. This method involves the restoration of small areas, or“islands”, within larger zones of
restoration. The method consists of hand weeding, to minimize soil disturbance, so that native plants can re-establish. The
method discourages the exposure of large areas to disturbance that would then be re-colonized quickly by weeds. Although
the method was primarily designed to allow existing native vegetation to recover and re-emerge, it presents a useful
methodology for the successful outplanting of native plants in areas that currently have none or very little. The strategy of
the Bradley method is to find pockets of existing native plants and expand those pockets through adjacent outplantings and
adjacent weed control, thus pushing the ecological balance away from weeds and towards native plants. Ideal conditions
are created for the regeneration of aggressive weeds if soil is extensive cleared and exposed to sunlight. By creating“strong
holds”of native vegetation, stable areas of restoration can be established that can be easily maintained. These strips of
established natives can then be expanded as resources allow and after the previous set of native plantings have grown in
and formed a dense cover. 19
ECOLOGICAL SUCCESSION
With natural competition among plants, and as trees and shrubs gain maturity, there will be a succession of the composition
of the landscape at Kawainui marsh. As open areas get more shaded, plant composition shifts. As some plants set seed, are
distributed by wind or birds, and regenerate at a quicker pace than other plants, they can shift the balance of a landscape.
Understanding the principal of succession can be useful in helping to direct restoration efforts. Pioneer species that do well
in the beginning and then fade as other plants become mature, can still serve an important function.
Figure 22: Uluhe Fern (Dicranopteris linearis).

Understanding Uluhe Fern as a Transition Species in
Mesic Forests: The natural ecosystem of Hawai‘i has its
own effective method of re-vegetation of highly disturbed
and phosphorus poor sites. When landslides occur, or
other natural disasters create raw open land, it is quickly
restored through the amazing Uluhe fern (Dicranopteris
linearis). A single mother plant can quickly cover hundreds
of square feet of area, and slowly revitalize exposed sub-
soil, protecting it from erosion and slowly turning it into
soil suitable for the establishment of other native plants
such as Koa and‘ōhi‘a lehua. This is nature’s way of native
forest succession and restoration in pre-historic Hawai‘i. It
would be of great value in restoration efforts to be able to
utilize uluhe fern as a restoration resource, unfortunately the
uluhe fern is notoriously hard to propagate. It is currently
unavailable for out-planting
Uluhe fern leaves are relatively short lived, but take a very
long time to decompose, thus they fix and hold carbon and
encourage soil micro-organisms, to the benefit of native
ecosystem development. The wicker of old stems traps
leaf litter of other plants that would otherwise decompose
quickly, thus creating a“nutrient sink”that keeps the soil
nutrient poor, otherwise the quick decomposition of
organics would benefit invasive species. The characteristics
of uluhe fern could make it a tool in reducing and
controlling invasive species in mesic forest restoration areas
if propagation methods can be successfully developed. 16
Uluhe fern prefers full sun, poor soil, and wet areas. It also
seems to naturalize in areas of low pH (high acidity), which
may be a key to its successful propagation.
Transition Plants for Dryforest Restoration:
Other potential transition plants more readily available then
uluhe fern might include the following.
a‘ali‘i (dodonaea viscosa)
Nanea (Vigna marina)
‘ūlei (Osteomeles anthyllidifolia)
‘ānapanapa (Colubrina asiatica)
‘ilie‘e (Plumbago zeylanica)
naio papa (Myoporum sandwicense)
‘uala – Hawaiian Sweet Potato (Ipomoea batatas)
FOCUSED PLANTING ISLANDS (KIPUKA)
Nucleus plantings that focus resources on a relatively small
island of planting, rather than attempting to spread out
planting uniformly over a large area, can be an effective
restoration approach. This will enable the establishment of
relatively stable native plant communities that can then be
expanded and merged as additional resources allow. This
also results in native plant seed and propagation material
sources for future expansion, as well as a mycorrhizal fungus
and endophytic fungus inoculum source.
Research from tropical forest restoration efforts in Costa
Rica have shown that creating small dense‘islands’of native
forests within larger area to be restored is a cost effective
and management efficient restoration approach. By setting
up various size test plots under various condition, and
comparing them with control plots over a 10-year period,
the research indicated that planting tree islands is an
effective and comparatively cheaper approach to accelerate
tropical forest recovery that better simulates the natural
recovery process than trying to plant entire large areas. 26
A critical minimum size for a tree island was about 100m2
(approx. 1,000 sq.ft.). The islands can become stable and
regenerative, and naturally expand with smaller‘islands’
coalescing together into larger areas over time.
CULTURAL PLANTINGS AND GATHERINGS
Research indicates that the restoration of lo‘i kalo (irrigated
pond fields for taro cultivation) within wetlands together
with native vegetation restoration can have positive effects
Figure 23: A Densely Planted Reforestation “Island” concept being tested at UH
Manoa campus - Shidler College of Business.

on improving water quality and mitigating storm water run-
off before entering wetlands. 29
ATTRACTING POLLINATORS
Many of the native pollinators, such as birds and insects,
are no longer supported in a forest because of reduced
diversity of plant species. Attracting pollinators can help
with the regeneration of native plants. Leave brush on
site to attract diversity. A dripping faucet or irrigation drip
emitters can help attract predator insects. Stalks of sisal or
the soft wood branches of trimmed trees can attract wood
bees which can help with pollination. Leave populations of
wild honey bee hives in place if away from major trails, but
mark locations with signage, flagging, or white paint, as a
warning.
Planting a high diversity of plants in the same general area
can be important for the sustainability of pollinators, such as
bees. When one plant species provides food for pollinators
while another plant species is not in flower, the first plant
is helping the second plant by enabling the pollinators to
survive and carry over. 37
RECORD KEEPING
Mapping and data collection will be very useful to long
term efforts of wetland and forest restoration at Kawainui
Marsh.
Record Keeping should include:
• Site Location / existing conditions
• Species and source
• Plant size and general condition
• Planting date
• Treatments (fertilizes, mulch applications, insect
control, etc)
• Weed, rodent, ungulate controls
• Survival rates after 12, 18, and 24 months
By keeping records of the propagation material source for
out plantings, a known lineage can be established that will
enable confidence in using future material for propagation
from the plants as they mature. This can provide a
convenient and accessible seed source for difficult to get
plant material for further restoration efforts at the marsh.
RFID tagging: New technology can greatly aid in keeping
track of plants. RFID (Radio-frequency identification) tags
can be inserted inside of plants. A smart phone can read
tags and associated information. RFID are composed of
an electronic label, called a tag (frequently a microchip), a
reader and a management system. The tag incorporates a
unique identifying code received by the reader. These can
be implanted into the plants, or externally applied. They can
then be read by tablet PC’s or smart phones.
NURSERY STOCK MATERIAL
Most native plants have evolved with a symbiotic
relationship with native mycorrhizal fungus and endophytic
fungus. The standard use of“sterile”soil for the propagation
of native plants in greenhouses, together with extensive
use of fertilizers and fungicides, can effectively eliminate
AM (arbuscular mycorrhizal) inoculation and reduce the
diversity of endophytes. The result is that these important
fungus are essentially absent from native plants grown with
standard greenhouse methods. 9
Research indicates that the
accidental or natural inoculation of plants with AM in the
nursery seldom happens. 9
• An important consideration in AM fungus production is
the level of available Phosphorus in the media in which
the plant hosts are grown. Plants growing in high P
situations limit colonization of their roots by AM fungi.
In effect, they are deciding to limit the“cost”(in terms of
sugar) of the symbiosis in the absence of benefit (in this
case, improved uptake of phosphorus) since the roots can
function well enough on their own in the high nutrient
situation.
Figure 24: Lo‘i with kalo.

Propagation from cuttings routinely become mycorrhizal,
but the variety of AM might not be ideal and additional
inoculation with AM of known association to the plant
species has shown to be of benefit.
Fertilizations of nursery material should be discontinued at
least 3 months prior to out planting, to reduce transplant
shock (from the desiccation of accelerated new growth).
Trimming of larger leaves might be helpful at time of
planting.
Plants should be well grown in and vigorous. For example,
using 1 and 2 gallon Stuewe® tree pots. Inspect for insects,
such as ants or mites.
Smaller sized shallow pots, such as typical 4”pots, should be
avoided unless temporary irrigation will be provided.
Double dibbling to enhance fiber structure of root system
in pots for outplanting. Pot native plants with an annual or
short lived perennial, to bind the root ball for transplanting.
Plants to add for double dibbling could include native mint,
‘ōhai, rye grasses, bidens, bacopa, or ferns. Trim back these
secondary plants at time of planting if water stress of main
plant is a concern.
PLANT SELECTION FOR SPECIES PROTECTION
The selection of specific species for out planting in a native
restoration setting should be designed to encourage
the genetic integrity of any given species used. Planting
together different species within the same genus that have
the potential for interbreeding should be avoided. For
example, the out planting of several different species of
native white hibiscus, or different species of loulu palm, in
close proximity, could potentially result in adulteration of
the genetic offspring of those plant species. It defeats the
purpose of restoration as a means of preserving biodiversity
and makes the seed production of these plants useless for
further out planting efforts.
• Nursery material should be qualified as to the source of
propagation material used.
• Preference should be given to seed grown material over
plants grown from cuttings. Plants propagated from
cuttings are genetically similar, thus do not help increase
genetic viability of a species.
• Select plant species not just for the perpetuation of that
specific species, but also for what it might provide for
other endangered species, such as plants that help native
birds and insects pollinators that benefit other plant.
Figure 25: Mamaki - Important plant for the Hawaiian Monarch Butterﬂy.

NA POHAKU O HAUWAHINE – LESSONS LEARNED
The ongoing restoration work at Na Pohaku O Hauwahine represents a useful example for the evaluation of native plant
species and planting methods for use in the restoration of dryland forests on O’ahu. This 12 acre restoration effort along
Kapa‘a Quarry Road near Kailua, adjacent to Kawainui Marsh, is an ongoing experiment in the restoration of a native dryland
forest. Currently, over 80 different species of native and cultural Hawaiian plants have been successfully out-planted and
maintained at this restoration site, thanks to the tremendous support of community volunteers, and the active direction
from ecologist and aquatic biologist Eric Guinther, as well as others. The forest restoration work has reached an important
milestone of maturity, and represents a critical nucleus and resource for the continued restoration of the dryland forest
ecosystem around the marsh.
More information can be found at: http://www.koolau.net/NPEG/NaPohaku_Intro.html Or contact Eric Guinther at:
Guinther@hawaii.rr.com
Figure 26: Clearing of invasive plants at Na Pohaku o Hauwahine in June 2000. Figure 27: Same area 14 years later with restored native forest.
Planting Soil
The use of some typical horticultural practices for planting, such as the use of a rich potting
soil, fertilizer, or backfilling planting holes with amended soil, can be inappropriate for native
plant restoration.
• Using imported backfill soil with higher organic and nutrient values then existing native
soil, can cause quick growth for new plantings but long term failure, as root growth can
be shallow and root penetration into surrounding soil can be minimal.
• Higher nutrient backfill soil can also cause the quick growth of weeds and attract insects
to the flush of new growth.
• Light weight potting mixes can dry out quickly, with a reduced lateral moisture transfer
from surrounding soil and sub-soil.
• For nursery plants that have been potted in a light weight, high organic soil mix, it can
sometimes be beneficial to wash away a portion of potting soil prior to planting, to allow
immediate contact of native soil with roots.

TYPICAL PLANTING GUIDELINES
• Untangle girdling roots prior to planting.
• Use a power auger if planting large quantities to increase planting productivity.
• High nitrogen and phosphorus fertilizers might encourage weed growth and make plants more
susceptible to insect pests and dehydration.
• Backfill with existing on-site soil. Inoculate with native mycorrhizae from nearby soil with mature
plants of the same species, if available. Do not amend backfill soil with organics or fertilizers.
• Cluster plantings into focused“islands”to enhance weed control and to trap organic matter.
• Lightly pack soil. Level soil surface to top of root flair. Water hole first before planting if
surrounding soil is dry.
• Use a temporary wind shield if needed till plant establishment. Plant wind tolerant plants to
shelter other plants on exposed sites.
• Mulch base with available leaf litter, logs, or rocks.
• Mark smaller plants with flags or stakes to protect from weeding or trampling.
• Higher density plantings generally are more successful.

MULCH
Mulch is shredded wood applied as top-dressing to soil.
When used properly, mulch can be very beneficial. Mulch
can suppress weeds by physically blocking them from
sunlight, but also has other benefits. Use coarse, well-
draining mulch, such as wood chips or shredded wood that
typically cannot pass through a 1/2”diameter sieve. How to
use mulch:
1. In immediate vicinity of new plantings, apply coarse
mulch (3”deep) on down slope side of plants, and
only lightly (1”deep) on up-hill side of plants. This is
to reduce erosion and weed growth below the plant,
while allowing ample water penetration from rain
events to water the plants. Mulch acts as a barrier that
will help to capture water run-off at the base of plants
on slopes. If drip irrigation is provided, a deeper layer of
mulch can be used.
2. Do not pile mulch up against the base of plants. Pull
back about 4”from plant trunks.
3. Thoroughly wet ground just prior to applying mulch.
4. Do not use well composted mulch. Fresh coarse mulch
is better for native plants, as it is less likely to block
water penetration into the soil from rain, and will host
important fungus that will benefit native plants. Well
composted mulch can provide a nutrient overload
which will reduce the mycorrhizal dependency of
native plants.
5. Do not use mulch comprised of grass clippings, leaf
material, or wood sources that are very soft. These
mulches block water penetration and decompose
quickly, providing nutrient overloading for native plants
that encourages weed growth to out compete native
plants.
6. After plants have become established (approx. 6
months), re-apply a heavy cover of coarse mulch to
reduce weeds until there is sufficient growth of the
native plant such that it successfully shades out weeds
or otherwise successfully competes.
7. Mulch piles should be monitored for evidence of
Coconut Rhinoceros Beetles (CRB). Large stock piles of
mulch should be turned occasionally (approx. every two
weeks), so that temperature of mulch is kept between
100 deg and 140 deg F. Ideally, segregate all palm
material from other plant material when producing
mulch. Do not move material off-site, but use up mulch
piles quickly without letting them deeply compost.
CRB larvae have a relatively long development time.
Immediately report the detection of CRB to the state
pest hotline at 643-PEST (7378). Note that the Oriental
Flower Beetle larvae can be mistaken for the CRB.
Beneﬁts of Mulch
• Cools soil and Reduces soil compaction.
• Suppresses weed growth.
• Encourages and feeds useful soil microbes
• Coarse Mulch derived from hard wood plants
decomposes slowly to enrich soil fertility and humus, and
nurture beneficial soil microorganisms.
• Helps to neutralize extreme soil pH levels.
• Reduces soil erosion on slopes.
• Recycles a renewable resource, helping to sequester
carbon.
• Helps to mark locations of new plantings, thus reducing
potential for trampling, weedwacking, or mowing.
Negative Aspects
• Can become hydrophobic if applied too thick or mulch is
too fine, not allowing water to penetrate into soil.
• Cost and labor to apply
• Can girdle trunks at base of plants if piled against trunks.
• Needs to be replenished to be effective.
• Can decompose too quickly if derived from leaves and

stems of non-native plants soft wood species and grasses.
• Piles of mulch more than a few inches deep can become breeding grounds for the
Coconut Rhinoceros Beetle.
• Very large piles of mulch can spontaneously combust if not managed properly.
TREE LOGS
Fresh logs of Kukui, Milo, Kamani, or other hard wood trees can be of great benefit to native
plant restoration. Tree logs can help cool soil and prevent weed growth next to newly
planted plants, reduce erosion, retain moisture, and host beneficial micro-organisms as
it decomposes. Logs also help to mark locations of new plants and reduce the likelihood
of them being stepped on. They can define maintenance boundaries, helping to prevent
mowing or weed whacking accidents.
Using cut logs around new plantings can help to prevent damage from wild chickens, which
will tend to scratch and forage in fresh mulch, and help prevent pigs from routing out new
plants.
IMPORTANCE OF AN ORGANIC SUBSTRATE
The activation of the soil microbial community through the use of mulch, logs, and the
retention of persistent leaf litter, may be a vital component for the regeneration of native
plants. Research has shown that the seedling abundance of native Hawaiian plants can
be strongly associated with the quality of the thin top layer of soil (humus), often called
the organic substrate. In a study looking at seedling regeneration patterns in a Hawaiian
montane wet forest, it was noted that most seedling recruitments were found within
the organic substrate (decomposing tree logs and root mats), instead of in open mineral
soil. This appears to be related to the complex interactions between seed and native soil
microbiology. 30
Figure 28: Place logs parallel to slopes to retain leaf litter and mulch at base of new plantings.

Koa
Acacia koa
Endemic
Ko‘oloa ‘ula
Abu lon menziesii
Endemic
Koai‘a
Acacia koaia
Endemic
Maile
Alixia oliviformis.
Endemic
Uhiuhi
Caesalpinia kavaiensis
Endemic
Maiapilo
Capparis sandwichiana
Endemic
DRYLAND PLANTS
Hame
An desma spp.
Endemic
Ko‘oko‘olau
Bidens sp.
Endemic
‘Āwikiwiki
Canavalia galeata
Endemic
Carex
Carex wahuensis
Endemic
Kāmanomano
Cenchrus agrimonioides
Endemic
‘Akoko
Chamaesyce spp.
Endemic

‘Uki‘uki
Dianella sandwicensis
Indigenous
Laukahi Fern
Cyclosorus hudsonianus
Endemic
Pāpala
Charpen era spp.
Endemic
‘Āheahea,
Chenopodium oahuense
Endemic
Huehue
Cocculus trilobus
Indigenous
Photo: “Cocculus trilobus.JPG.”
by Dalgial is licensed under (CC
BY-SA 3.0)
‘Anapanapa
Colubrina asia ca
Indigenous
Kou
Cordia subcordata
Indigenous
Lama
Diospyros sandwicensis
Endemic
A‘ali‘i
Dodonaea viscosa
Indigenous
Emoloa
Eragros s variabilis
Endemic
Wiliwili
Erythrina sandwicensis
Endemic
Nā‘ū
Gardenia brighamii
Endemic
DRYLAND PLANTS

Koki‘o ke‘oke‘o
Hibiscus arno anus
Endemic
Ōhi‘a
Metrosideros polymorpha
Endemic
Kupukupu
Nephrolepis cordifolia
Indigenous
DRYLAND PLANTS
Ma‘o
Gossypium tomentosum
Endemic
Ma‘o hau hele
Hibiscus brackenridgei
Endemic
Koki‘o
Hibiscus spp.
Endemic
Hau
Hibiscus liaceus
Indigenous
Palapalai
Microlepia strigosa
Indigenous
Naio
Myoporum sandwicense.
Indigenous
‘Aiea
Nothocestrum la folium
Endemic
Photo: “Starr 031111-0157
Nothocestrum latifolium.jpg.”
by Forest & Kim Starr is licensed
under (CC BY 3.0)
Kulu‘i
Notorhichium spp.
Endemic
‘Ūlei
Osteomeles anthylidifolia
Indigenous

DRYLAND PLANTS
Hala
Pandanus spp.
Indigenous
Ho‘awa
Pi osporum spp.
Endemic
‘Ilie‘e
Plumbago zeylanica
Indigenous
Āla‘a
Pouteria sandwicensis
Endemic
Photo: “Starr 030210-0004
Pouteria sandwicensis.jpg” by
Forest & Kim Starr is licensed
under (CC BY 3.0)
Loulu
Pritchardia mar i
Endemic
Alahe‘e
Psydrax odorata
Indigenous
Hao
Rauvolia sandwicensis
Endemic
‘Ohe makai
Polyscias sandwicensis
Endemic
‘Iliahi
Santalum spp.
Endemic
Pāpala kepau
Pisonia sp
Endemic
Hillebrand’s Brake
Fern
Pteris hillebrandii
Endemic
neleau
Rhus sandwicensis
Endemic

Lonomea,
Sapindus oahuensis
Endemic
DRYLAND PLANTS
Naupaka kuahiwi
Scaevola gaudichaudiana
Endemic
Kolomana
Senna gaudichaudii
Indigenous
‘Ōhai
Sesbania tomentosa
Endemic
Milo
Thespesia populnea
Indigenous
Āki‘a
Wikstroemia uva-ursi
Endemic
Māmane
Sophora chrysophylla
Endemic
Photo: C.H.Lamoureux)

CULTURAL PLANTS
Kukui
Aleurites moluccana
Polynesian-Introduced
Kī
Cordyline fru cosa
Noni
Morinda citrifolia
‘Awa
Piper methys cum
Kō
Saccharum oﬃcinarum
Kalo
Colocasia esculenta
Ulu
Artocarpus spp.
Oh‘e
Schizostachyum glaucifolium
‘uala
Ipomoea batatas

Figure 29: A tangled Hau tree forest creates a buffer zone between the wetland and upland areas of Kawainui
marsh.
PREHISTORIC PLANTS OF LOW LAND FORESTS
Resent pollen studies taken from sediment sequences from
core samples from marsh areas on O‘ahu, and from a sink
hole area on Kaua‘i, have revealed a rich selection of native
plants existing at those sites before human habitation of
Hawai‘i, and indicate what has been lost. 31
The pollen record shows that the pre-polynesian vegetation
that dominated the area of O’ahu wetlands included such
native plants as the loulu palm (Pritchardia spp.), together
with a‘ali‘i (Dodonaea viscosa), hāpu‘u tree fern (Cibotium
spp.), and Kanaloa (Kanaloa kahoolawensis), a plant that is
no longer found on O‘ahu.
In addition to pollen, actual seeds recovered from core
samples can also help to establish what plants had inhabited
the primevel native forests, and how the ecosystems of
Hawai‘i have changed with human habitation over the last
1500 years. 32
The pollen record shows a very distinct and sudden
difference in plant composition in low elevation areas
between the pre-human period in Hawai‘i and the arrival of
the polynesians.
Historic Native Forest Plants of Kawainui Marsh, Oahu
(based on pollen and seed samples)
• Antidesma spp. (hame)
• Broussaisia spp. (akiahala)
• Chenopodium spp. (aweoweo)
• Cibotium spp. (hāpu‘u)
• Claoxylon spp. (po‘olā)
• Colubrina spp. (‘anapanapa)
• Cyperaceae spp. (such as: pu‘uka‘a, carex)
• Dodonaea viscosa (‘a‘ali‘i)
• Fragaria spp. (‘ohelo papa) - native strawberry)
• Kadua spp. (manono) - now extinct on O‘ahu
• Kanaloa spp. (kanaloa)
• Myoporum spp. (naio)
• Myrtaceae family (possibly Metrosideros spp.
(‘Ohi’a lehua))
• Pritchardia spp. (loulu palm)
• Schoenoplectus lacustris (‘aka‘akai / Bulrush)
• Rhus sandwicensis (neleau)
• Various fern and grass species

WATERING
Rainfall varies greatly in Hawai‘i depending on specific locations, with low elevation
dryland forest areas getting typically between 30 to 80 inches of rainfall annually.
Amounts probably vary significantly between windward and leeward locations, and
with even small incrimental changes in elevation. The most precipitation occurs in
the months of November and December, with the lowest rainfall occurring between
the months of June to August.
In many locations, out planting has been done successfully without the need of
much supplemental watering, when timed with the seasonal rainfall patterns.
Without supplemental water, new plants can grow very slowly and might not be
able to compete with adjacent weed growth. When relying on rainfall only, the
use of mulch for weed control can be a problem as when the mulch becomes dry
between rain events, it can become hydrophobic and shed water away from small
plants, or absorb water before it reaches the root zone. Leaving the soil dry under
the mulch Alternatively, using mulch can greatly facilitate weed control and can
help bio-activate important soil microorganisms. And once the soil is wet, mulch can
help retain soil moisture between rainfalls. An ideal compromise might be to use a
temporary drip irrigation system during establishment (first full year after planting)
to apply water directly to the root zone of new plantings. This will enable the use of a
thick layer of mulch for weed suppression and other benefits.
When providing supplemental irrigation, water deeply and in-frequently. Shallow
watering will encourage shallow root growth with plants easily blown over or
unlikely to survive drought periods after irrigation is removed. Frequent shallow
watering also encourages weed growth. Water enough for plant survival, not for
maximum growth rate!
Planting at the right time of the year can greatly reduce the need for supplemental
water during an establishment period. For good growth, newly planted plants will
need the equivalent of about 1”of rain per week for the first few months. Typically,
that’s about the equvianlt of 1 gallon of supplimental water per plant per week, if no
rainfall.
Use one drip emitter per plant with surface installation after planting.
• Use deep watering tube for trees and shrubs to apply water below soil level
• Water every other day for the first week to reduce wilting and transplant shock
• Water every other day for second week
• Water deeply once per week through to first 6 months
• Water deeply only as needed after month 6
For irrigation on steep slopes, use heavy mulch or logs on downhill side of plant to
retain or slow water runoff and allow percolation at base of plant. Place drip heads
off of spaghetti tubing to stake at base of plant, rather than using evenly spaced
in-pipe emitters or button emitters along main drip line piping. Targeting the base of
plants will help reduce weed growth and will be more efficient application of water.

RAINWATER CATCHMENT SYSTEM
Due to limited availability of domestic water supply, a
rainwater catchment system can be utilized to provide
water for the drip system during the establishment period,
and to provide water for continuing out-planting efforts. At
times of insufficient rainfall, the water tank can be filled by a
water truck, if needed and in an accessible location.
Water pressure increases 0.434 pounds per square inch (psi)
for every foot increase of elevation difference. Thus, for every
10 feet of elevation change below a water tank, the pressure
in a water line will increase by 4.34 psi. A typical drip system
needs at least 15 psi to operate properly, to activate electric
valves and meet performance standards of drip emitters.
This means that the upper most portion of a drip system
should be located at least 35 ft lower than the water source
tank to meet manufacturers designed performance levels
of standard drip irrigation equipment. The use of a“no
pressure”hose valve/timer (such as Toro“Zero Pressure
Dial Timer’) together with low pressure emitters (such as
Netafim BD series emitters) can be used to create a
low pressure drip system if elevation of water catchment
system will be within 35ft elevation difference of the drip
system. If pressure will exceed 30 psi, due to elevation of
water tank over 70ft above distribution, then a pressure
regulator should be used.

PEST CONTROL
ANTS
Hawaiian forest evolved without ants. Ants can shift the soil micro-organisms to the
detriment of native plants, and can also nurture and protect harmful invasive insects,
such as aphids, scales, and mealy bugs. Ants also can increase the rate of nutrient
cycling and vegetation decomposition, to the benefit of non-native weeds.
Ants should be aggressively controlled during the early stages of native plant
restoration. The complete elimination of ants in a restoration area is not practical, but
a significant reduction in the presence of ants can be achieved with minor effort,
and can significantly reduce insect problems during the critical first year of plant
establishment.
A mix of dry and wet baits should be alternated for increased effectiveness.
Most ant species can be readily controlled (temporarily) with standard ant baits. One
species in Hawai‘i that is an exception to this is the White Footed Ant. It is notorious
for being difficult to control with standard baits, since its feeding behavior is different
than most other ant species. As a result, the White Footed Ant often moves in and
replaces other ant species that have been controlled by baits. Multiple applications
of ant baits, such as Amdro®, over several weeks, will help to reduce and possibly
eliminate near-by nests of White Footed ants. Fortunately, in terms of wetland and
bird habitat, White Footed ants are not stinging, and seem to be less of a nuisance
than some other ant species, thus being the“lesser of evils”, although they can
encourage and support the presence of detrimental insects, such as white fly and
aphids, on native plants.
Trees and shrubs that are particularly sensitive to aphids, mealy bug, or scale
problems should be specifically targeted for ant control. An effective and
direct method of ant control on specific plant materials that is non-toxic to the
Figure 30: These liquid and granular ant control products are low toxic to the
environment and effective at reducing ant populations with repeat applications.

surroundings is the use of sticky barriers around the trunk.
Products, such as TangleFoot, applied as a band around
the lower trunk, can eliminate ant and rose beetle access
to the canopy of plants for several months with a single
application. A single tube of TangleFoot can be applied to
about 20 small trees or shrubs. An application of TangleFoot
is also affective against Japanese Rose Beetles, particularly
for Hibiscus brachenridgei.
The only apparently beneficial aspect of ants in Hawaii
is that they have been shown to harbor and spread
mycorrhizal fungus spores and propagules, presumably
from ants cutting root pieces from subsoil and bringing
them to the surface. 14
However, the detrimental effects of
invasive ant, worm, and other insect species in Hawai‘i most
likely greatly outweighs any beneficial effects.
CHICKENS
Feral Chickens in restoraton areas can be very destructive to
new plantings and restoration efforts. Chickens will forage
in fresh mulch areas and damp soil, scattering mulch and
even up-rooting small plants. Placing rocks, boulders, or
logs around the base of new plantings can be an effective
deterrent to damage by chickens, with an added benefit of
some weed control. .
RAT CONTROL
Research shows that reduction in rat populations can
significantly improve regeneration of native plants,
including Hala, Loulu Palm, Pāpala kēpau,‘Iliahi, and
other plants. Use of bait boxes can be effective. A newer
method utilizes a self-resetting automatic rat trap powered
by compressed CO2, which can be very cost effective
over conventional rat traps. Information on the use and
effectiveness of a CO2 powered automatic rat trap in Hawai‘i
can be found here: http://manoa.hawaii.edu/hpicesu/
DPW/other/A24.pdf.
Figure 33: The A24 automatic CO2 powered rat trap manufactured by Goodnature
can dispatch up to 24 rats with each CO2 canister (www.goodnature.co.nz).
Figure 32: Newly planted loulu palm is protected from chickens by logs placed
around base of plant.
Figure 31: An application of Tanglefoot Insect Repellent is a good non-toxic method
to defend small trees from ant and rosebeetle problems.

SLUGS AND SNAILS
Newly out planted seedlings should be monitored for
predation by snails and slugs. Effective chemical controls,
such as Sluggo, are readily available and approved for use in
sensitive areas.
Research indicates that invasive slugs and snails can shift
plant communities in favor of invasive plants species, since
invasive slugs and snails can have a preference for native
plant species over non-native species. Favorite targets of
snails include Hibiscus arnottianus and H. clayi, native ferns,
and Brighamia insignis (Alula). Apparent exceptions are‘ohi‘a
lehua, Papala kepau, lama trees, and Hibiscus bracenridgei,
which all seem to be avoided by snails. Invasive Strawberry
Guava is avoided by the giant African snail, which may help
to shift a native plant community to the successful invasion
of the Strawberry Guava tree.
Copper tape, when used in a double wide band, can be
a very effective and long term deterrent to snails on trees
and tall shrubs. Large snails can reach over single width
tape applications and proceed beyond. Crimp tape to allow
expansion of trunk.
Figure 34: A hungry African Snail has second thoughts about crossing a band of
copper tape on a native Hibiscus plant.
Pest of Concern – Not yet established on O‘ahu
These pests have been identified as high potential
threats to O‘ahu’s ecosystem. Call Hawai‘i’s Pest
Hotline if Observed on O‘ahu: 643-7378
Myoporum Thrips
Attacks: Naio (False Sandalwood)
Symptoms: Causes gall-like damage to leaves and shoots
Status: Found only on Big Island (South Kohala, North Kona)
Hala Scale
Attacks: Pandanus (hala) leaves
Symptoms: Leaves turn yellow; also found on dead leaves
Status: Found only on Maui
Red Palm Weevil
Attacks: Palms
Symptoms: Large larvae or grubs tunnel in crown feeding
on sap. Larvae form cocoons in palm fibers before pupating.
Wilting of crown and leaves. White or yellow jelly-like fluid
flowing from grub holes.
Status: Not yet present in Hawai’i.
Red Palm Mite
Attacks: Palms, Bananas, Hala
Symptoms: Yellowing of leaves. Red mites and shed white
“skins” visible on underside of leaves.
Status: Not yet present in Hawai‘i.
Coconut Rhinoceros Beetle
Attacks: Palms and Hala
Symptoms: Adult beetles bore into palm crown cutting
through developing leaves. V-shaped cut in fronds.
Status: Present in Hawai‘i in isolated areas. Currently
undergoing aggressive control measures.
Little Red Fire Ant
Attacks: People, pets, birds, agriculture
Status: Present on in Hawai‘i Island.
Ramie Caterpillers
Attacks: Mamaki and akolea
Status: Present on Maui.

WEED CONTROL and MAINTENANCE
Perhaps the biggest challenge to restoring native plant forests is the control of
aggressive vegetation that quickly overwhelms restoration plantings. Aggressive
weeding activities, such as the use of weed wackers or herbicides, can damage
restoration plantings and prevent natural re-generation of native plant seedlings.
Ideally, weed control efforts should allow for protection and regeneration of
desirable plants. Maintenance staff and volunteers need to be able to identify
weeds vs natives. A plant identification photo guide or on-site growing area should
be provided that identifies the primary weeds that might be encountered during
maintenance operations, as well as plants to be protected. Small native plants that
germinate from new plantings or from natural regeneration should be flagged or
caged for protection.
METHODS
Shade: The single most effective weed control measure is providing shade.
Encouraging the quick growth of canopy trees, such as Milo, Koa, or Kou, can greatly
reduce aggressive weeds. Leaving mature existing trees in place that are minimally
invasive to create hybrid ecosystems can be another good strategy.
There will be more weeding in the short term if restoration sites are completely
cleared in preparation for planting. Considering leaving larger non-native trees
in place. Girdle the trunks and leave in place to act as frameworks or“trellises”for
planting quickly growing native vines that can replace the non-native canopy. Pre-
notch the trees so that they eventually will fall in a controlled direction. Another
approach is to plant fast growing native plants, or even non-native but not invasive
plants, that can act as successional plantings with the intention of later removal as
desired native plantings mature.
Using weed cloth to shade out ground weeds can be effective if used properly. Do
not plant in cut outs of large lengths of weed cloth, as later removal can become
very difficult and messy, and also can prevent the accumulation of leaf litter and
mulch that can be useful to enhance important soil ecology. Use smaller squares of
weed cloth for individual plants. Create a slight depression in the ground, or slope
the weed cloth so that it can act as rainwater catchment for the plant. Using weed
cloth as a border along the upper slopes of restoration“islands”can be useful, as it
creates a clear buffer zone that can easily be shifted later to allow for expansion of
the plantings
Spraying: Chemical herbicides can play and effective role in the control of ground
vegetation before, during, and after restoration planting. Some herbicides have a
residual effect that can be detrimental to new plants. Use herbicides well in advance
of outplanting activities. Keep in mind the following:
• Mechanical and chemical weed control can have harmful effects on the native soil
ecology. The over-application of Herbicides can kill beneficial soil microorganisms,
including mycorrhizal fungus and bacteria. Herbicides, such as Habitat®, can take
3 to 5 days to dissipate in water, and 26 to 143 days to dissipate in soil, which
can negatively affect the success of outplantings due to absorption of residual
herbicide.

• Cut large weeds and small trees at base, allow for flush of
re-growth, then spray or apply herbicide directly to cut
trunks. When applying systemic herbicides, allow for some
re-growth of weeds to effectively use herbicides, such as
Aquamaster. Herbicides (such as Garlon®4) used on cut
stumps should be applied immediately after cut is made
so that plant cells are still actively translocating.
• Do not till the soil, but plant with no-till. Dig holes only
as large as the root ball of the plant. Use heavy mulch
topdressing to help control weeds.
• Leave green waste on site. If cut weeds have seeds, pile
weeds at peripheral areas to compost.
• Habitat® herbicide (EPA Reg No. 241-426)
• Remove seed heads or fruit of invasive species if full
eradication is not practical. For example, regularly mowing
or weed whacking of grasses and weeds before flowering
can help reduce the seed bank loading.
• Avoid unnecessary vegetation clearing or soil tilling that
will allow for quick regeneration of aggressive weeds that
might have otherwise been shaded or crowded out by
less aggressive and less noxious weed species. Consider
leaving weed species that are the“lesser of evils”for
future eradication, and focus resources only on the more
aggressive and damaging species.
• Avoid the use of pre-emergent or post-emergent
herbicides, as these can adversely effect the soil ecology
for important native mycorrhizae and bacteria. They can
persist in the soil for a long time, delaying or reducing
the success of out-planting of native plants and the
regeneration of seedlings.
• For a“natural”weed control in chemical free zones, use
an Epson salt solution on fresh cut stumps, at a rate of
2 tblspoons in a quart of water. Safely kills plants while
adding magnesium to the soil.
Figure 35: Planting in weed fabric reduces maintenance and with slight depressions can create mini rainwater catchment for individual plants.

Pressure washers – At a force of 2800 psi, a pressure
washer with an abrasive can cut through guinea/California
grass. Knock down grass to a stump with a pressure washer,
let some growth come back, then treat with chemical (such
as Epson salt or glycophosphates, or salt)
Trunk Girdling
Removing a strip of bark around the entire circumference of
a tree trunk will kill it. Trunk girdling can be labor intensive,
and can take up to a year or longer for the tree to die, but
can be an effective way to kill larger trees. Girdling and
leaving trees in place to slowly loose their canopies, can be
an effective means of reducing weed growth around new
plantings before open sunlight might encourage rapid
weed growth.
Basal Frilling
Basal Frilling is notching the bark of a tree with a small ax or
hatchet, and then squirting or painting a herbicide directly
into the sapwood. The herbicide is translocated throughout
the plant through the active transpiration of leaves. The
result is a slow decline in the trees, with a gradual opening
of the canopy. Depending on the species, it may take up
to a year for the tree to die, giving the understory plants a
chance to fill in and get started before a completely open
canopy would encourage rapid growth of invasive weeds.
The remaining dead tree can be left in place as a support
for native vines that will quickly replace the invasive canopy
with a native one. If the direction of fall of a dead tree is
critical so that it does not land on new or important plants,
notch the truck to control the direction of fall.
Cut Stump Method
Smaller trees or narrow trunk trees and large shrubs can be
cut to ground level or near ground level, using handsaws
or chainsaws. Stumps should be cut so they are close to
the ground, or waste height, to minimize the danger of
anyone tripping on or falling onto the cut end. Cuts should
be made level so that herbicide is retained on the surface
of the stump to allow for absorption into the plant. It is
important that the herbicide is applied immediately after
cutting, as the absorption into the trunk diminishes quickly
with time. For larger stumps, herbicide can be applied to
just the cambium and outer xylem layers, where the active
translocation will occur.
Basal Bark Application
Trees with thin or young bark can be controlled by the
application of herbicide directly to the lower base or stems.
This can be particularly effective on shrubs or plants with
numerous low branching stems. A 20% concentration of
Triclopyr ester herbicide, mixed with crop oil and applied
to the base or basal area of trees and shrubs, can be used
to control Strawberry guava and other weedy trees and
vines. Even young albizia trees can be killed by basal bark
applications.
Tree Injection
New tree injection technology is making tree injections as
a delivery method for herbicide applications more practical
and cost effective. It can be particularly useful for larger
trees, and can reduce the amount of chemicals needed that
other treatment methods might entail.
Figure 36: Cut stump with Garlon®
4 application.

PLANTS AND PLANTING METHODS R-1
REFERENCES
1. Bill Garnett, Wiliwili Hawaiian Plants, restoration
techniques, LICH Conference, 2013
2. The Instant Expert Guide to Mycorrhiza, the connection
for functional Ecosystems , Ted St. John, Ph.D.: ., April
2000, http://green-diamond-biological.com/wp-
content/uploads/2012/03/Mycorrhiza-Primer.pdf
3. Do Closely Related Native and Exotic Fern Species Differ
in Mycorrhizal Colonization?, Rebekah M. Outman,
Family Ties and Plant Invasions: 2012
4. Soil Fertility and the Impact of Exotic Invasion on
Microbial Communities in Hawaiian Forests , Jenny Kao-
Kniffin, , 2008
5. The Use of Mycorrhizae in Native Plant Production,
University of Washington, June 2006
6. The effect of introduced canopy tree species on the
soil microbial community in a montane tropical forest,
Pacific Science, vol 66, no. 2, September 21, 2011 (early
view), Hannah B. Lynch
7. David Lonsdale, Life within & beneath the tree, seminar,
November 2005, Keele University.
8. Mycorrhizal Dependency of Some Endemic and
Endangered Hawaiian Plant Species, J.N. Gemma, R.E.
Koske, and M. Habte, American Journal of Botany,
89(2):337-345. 2002
9. Vesicular-arbuscular Mycorrhizal Inoculation of
Hawaiian Plants: A Conservation Technique for
Endangered Tropical Species, R.E. Koske and J.N.
Gemma, Pacific Science (1995), vol 49, no.2: 181-191
10. Arbuscular Mycorrhizas: Producing and Applying
Arbuscular Mycorrhizal Inoculum. M. Habte and N.W.
Osorio, CTAHR bulletin, University of Hawaii at Manoa.
2001
11. Benjamin A. Sikes, When do arbuscular mycorrhizal
fungus protect plant roots from pathogens? , Plant
Signaling & Behavior 5-6,763-765; June 2010
12. Na Pohaku o Hauwahine (The Rocks of Hauwahine), Eric
Guinther, web site, 2012 http://www.koolau.net/NPEG/
NaPohaku_Intro.html
13. Mycorrhizal Fungi and Plant Nutrition, Plant Nutrient
Management in Hawaii’s Soils, J.A.Silva and R. Uchida,
College of Tropical Agriculture and Human Resources,
University of Hawaii at Manoa, 2000, Chapter 14, M.
Habte
14. Potential of earthworms, ants, millipedes, and termites
for dissemination of vesicular-arbuscular mycorrhizal
fungi in soil, K.M. Harinikumar, D.J. Bahyaraj, Biol Fertil
Soils (1994) 18:115-118
15. Effects of Exotic Plant Invasions on Soil Nutrient Cycling
Processes, Joan G. Ehrenfeld, Ecosystems, 2003, 6: 503-
523
16. The ecology of the climbing fern Dicranopteris linearis
on windward Mauna Loa, Hawai‘i, Journal of Ecology
1998, 86, 765-779, Ann E. Russell, James W. Raich, Peter
M. Vitousek.
17. Arbuscular Mycorrhizal Fungi as Potential
Bioprotectants Against Plant Pathogens, Mohd Sayeed
Akhtar, Zaki A. Siddiqui, Mycorrhizae: Sustainable
Agriculture and Forestry, chpt 3. , 2008.
18. Mycorrhizal symbiosis, Third Edition
19. Use of Mycorrhizae in Restoration of Hawaiian Habitats,
J.N. Gemma and R.E. Koske.
20. Bush Regeneration: The Practical Way to Eliminate Exotic
Plants from Natural Reserves. Bradley, Joan. Fremontia,
the journal of the California Native Plant Society, Vol 13,
No 2., July 1985
21. Developing Coastal Wetland Restoration Techniques to
Enhance Coastal Habitats at Ahua Reef, Joint Base Pearl
Harbor Hickam, Hawai‘i. Tech Note: 11-320.
22. Glomalin: Hiding Place for a Third of the World’s Carbon,
http://www.ars.usda.gov/is/ar/archive/sep02/
soil0902.htm
23. Effect of Mycorrhizal Fungi Inoculation and Humic
Acid on Vegetative Growth and Chemical Composition
of Acacia saligna Seedlings under Different Irrigation
Intervals, M.A. El-Khateeb, A.S. El-Leithy and B.A. Aljemaa,
Journal of Horticultural Science & Ornamental Plants 3
(3): 283-289, 2011
24. Complemented Effect of Humic Acid and Biofertilizers
on Wheat Productivity, Abou-Aly, Annals of Agric. Sc.,
Moshtohor, Vol. 47 (1): 2009
25. Soil as Carbon Storehouse: New Weapon in Climate
Fight?, Judith D. Schwartz, Yale Environment 360, Yale
School of Forestry & Environmental Studies, March 2014

R-2 PLANTS AND PLANTING METHODS HHF Planners Inc - Dec 2014
26. Planting‘Tree Island’Helps to Facilitate Tropical
Forest Recovery, Karen D. Holl, Society for Ecological
Restoration, SER News, vol 28, issue 1, March 2014
27. Nutrients obtained from leaf litter can improve the
growth of diptoerocarp seedlings, Francis Q. Brearley,
New Phytologist, May 2003
28. Mycorrhizae in Hawaiian Angiosperms: A Survey with
Implications for the Origin of the Native Flora, R.E. Koske,
American Journal of Botany 79(8): 853-862. 1992
29. Mahuahua‘Ai o Hoi: Lo‘i Kalo Restoration as a Strategy
for Enhancing Hydrological and Ecological Function
in the He‘eia Wetlands, Jonathan Kanekoa Kukea-
Shultz, Janice Renee Yoshioka, Hawai‘i Conservation
Conference, 2013.
30. Regeneration Patterns in a native dominated Hawaiian
montane wet forest, Rebecca Ostertag, et al, 94th ESA
Annual Meeting, 2009
31. Environmental Change and Prehistoric Polynesian
Settlement in Hawaii, J. Stephen Athens and Jerome V.
Ward, Asian Perspectives, Vol 32, no. 2, 1993
32. Floral Recoveries from the Lagoonal Facies of Kawai Nui
Marsh, O‘ahu, Robert Moye, HPU. 2001
33. Archaeological Reconnaissance Survey with Limited
Subsurface Testing in Support of the Kawainui Marsh
Wetland Restoration and Habitat Enhancement Project,
Kailua Ahupu‘a, Ko‘olaupoko District, O‘ahu; by Cultural
Surveys Hawai‘i, Inc, Dec 2011
34. Plant Virus Ecology, Marilyn J. Roossinck, PLoS Pathog,
May 23, 2013
35. Rapid nutrient cycling in leaf litter from invasive
plants in Hawai’i, Steven D. Allison, Peter M. Vitousek,
Oecologia (2004) 141: 612-619
36. Liko Na Pilina - The hybrid ecosystem project, Rebecca
Ostertag, Susan Cordell, Peter Vitousek. https://sites.
google.com/site/laurawarmanecology/likonapilina
37. Plant Biodiversity enhances bees and other insect
pollinators in agroecosystems. A review., Clara Nicholls,
Miguel Altieri. HAL Id: hal-01201380, 17 Sept 2015.

PLANTS AND PLANTING METHODS R-3
REGULATORY PERMITTING - WETLANDS
Work within designated wetlands in Hawaii are regulated
under the authority of the U.S. Army Corp of Engineers,
and other regulatory agencies.
U.S. Army Corp of Engineers
Individual Permits: usually required for projects consid-
ered large in scope and/or involving potentially conflict-
ing issues in environmentally sensitive areas.
Letters of Permission: a type of individual permit that may
be used to authorize activities in navigable waters where
the proposed work would be minor in scope, and would
have negligible adverse impacts on the aquatic environ-
ment, and is not controversial.
Nationwide Permits: a form of permit used to authorize
specific activities determined to have no more than mini-
mal impact on the aquatic environment.
Web Info: http://www.usace.army.mil/Missions/Civil-
Works/RegulatoryProgramandPermits.aspx
Honolulu Branch
Regulatory Branch, CEPOH-EC-R
U.S.Army Engineer District, Honolulu
Building 230
Fort Shafter, Hawaii 96858-5440
808 438-9258
Section 401: Water Quality Certification
Issuing Agency: Department of Health, Environmental
Management Division, Clean Water Branch
Filed in conjunction with the U.S. Army Corps permit.
All construction activities requiring a permit from the
U.S.Army Corps of Engineers need the certification before
the permit is issued.
Web page: http://health.hawaii.gov/cwb/site-map/clean-
water-branch-home-page/forms/
Department of Health Clean Water Branch:
Clean Water Branch
Environmental Management Division
State Department of Health
919 Ala Moana Blvd., Room 301
Honolulu, Hi 96814-4920
808 586-4309
NPDES PERMIT (National Pollutant Discharge Elimi-
nation System)
This permit is required before any effluent discharge can
be made from fixed point sources into surface waters.
General Permit Coverage for storm water from Construc-
tion activities greater that one acre.
Web Info: http://health.hawaii.gov/cwb/site-map/clean-
water-branch-home-page/forms/
Clean Water Branch
Environmental Management Division
State Department of Health
919 Ala Moana Blvd., Room 301
Honolulu, Hi 96814-4920
808 586-4309

Hawai‘i Low Land Mesic Forest Restoration Manual (May 2015)

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