Gardening with Native Plants - A Gardener’s Guide for Missouri
Chapter Four:Landscaping with Native Plants A Gardener’s Guide for Missouri
Landscaping with Native Plants A Gardener’s Guide for Missouri Introduction Gardening with native plants is becoming the norm rather than the exception in Missouri. The benefits of native landscaping are fueling a gardening movement that says “no” to pesticides and fertilizers and “yes” to biodiversity and creating more sustainable landscapes. Novice and professional gardeners are turning to native landscaping to reduce mainte- nance and promote plant and wildlife conservation. This manual will show you how to use native plants to cre- ate and maintain diverse and beauti- ful spaces. It describes new ways to garden lightly on the earth. Chapter Four: Landscaping with Native Plants provides tools garden- ers need to create and maintain suc- cessful native plant gardens. The information included here provides practical tips and details to ensure successful low-maintenance land- scapes. The previous three chap- ters include Reconstructing Tallgrass Native landscapes in the Whitmire Prairies, Rain Gardening, and Wildflower Garden, Shaw Nature Reserve. Control and Identification of Invasive Species. use of native plants in residential gar- den design, farming, parks, roadsides, and prairie restoration. Miller called his History of Native work “The Prairie Spirit in Landscape Landscaping Design”. One of the earliest practitioners of An early proponent of native landscap- Miller’s ideas was Ossian C. Simonds, ing was Wilhelm Miller who was a landscape architect who worked in appointed head of the University of the Chicago region. In a lecture pre- Illinois extension program in 1912. He sented in 1922, Simonds said, “Nature published a number of papers on theIntroduction
3teaches what to plant. By going to prairies, wetlands, river-bottom for-the neighboring woods and seeing ests, glades and upland savannas.the trees and plants and shrubs they They have evolved with the extremescontain, one can tell pretty accu- of our climate, a wide array of patho-rately what plants will do well in any gens and a variety of soil and mois-given locality.” Nearly 100 years ago ture types, creating a palette ofSimonds, Miller, and others understood durable and showy Missouri nativethat native plants are a good choice for plants that are the focus of landscapeuse in landscaping and they were right. gardening. Plants such as yellow wildToday native plants are used in resi- indigo (Baptisia sphaerocarpa), nativedential and commercial landscaping, to the tallgrass prairie, and white-highway projects, habitat restoration, tinged oak sedge (Carex albicans),storm-water management, for parks which grows in dry woodlands, areand corporate office buildings. easy-to-grow beauties being show- cased in botanical garden displays, Metro St. Louis Sewer District rain gardens, and homeowners’ flowerWhy Use Missouri Native beds. Gardeners who use MissouriPlants? native plants have more success than those who use plants from otherLocal Ecotype Native Plants regions of the United States.Missouri’s natural plant communitiesoffer a diversity of native plants togardeners. For thousands of years,they have been adapting to life inA typical Missouri creek in the Ozarks (left) and rocky glade (right) are homesto many native plants that are useful in native landscaping.
4 Landscaping with Native Plants A Gardener’s Guide for Missouri ensures seasonal interest, with the Eight Reasons to Use Native bonus of attracting colorful birds, but- Plants terflies and insects. For a Sense of Place For Stormwater Management People who have lived in one place for Rain gardens, bioretention and wet- a time develop images of their home land detention basins are a few best that create a sense of belonging and management practices in use. They familiarity. Those who have lived in slow down and absorb rain water, thus rural Missouri know about flowering reducing the quantity and velocity of dogwood. For instance, its blossoms stormwater runoff while improving and berries have made their mark in water quality. the hearts and thoughts of so many Missouri residents that it is the state See Chapter Two – Rain Gardening tree. Many people have recognized this and Storm Water Management for heart-felt connection with nature, and it details on planning, constructing and often is referred to as “sense of place”. maintaining rain gardens. For Beautification For Educational Opportunities Wildflowers, flowering vines, shrubs and trees offer a wide range of colors, Native plant gardens present end- textures and forms to create dynamic less opportunities for learning about seasonal displays. Grasses and sedges seasonal cycles, wildlife, and plant have interesting flowers and seed life cycles. Quiet spaces outside can heads and yellow–orange fall color. be used for art and reading classes. Shrubs and trees have fall color and Environmental and conservation topics berries that persist into the winter. are taught best outdoors. Choosing a wide assortment of plants Left: Luna moth perched on wood poppy. Right: Sulphur butterfly getting nectar from a New England aster blossom.
5 wild bergamot (Monarda fistulosa) and round-leaved groundsel (Senecio obova- tus) deter deer. Some plants repel deer because of their coarse, rough, hairy or spiny textures. This group includes rat- tlesnake master (Eryngium yuccifolium) and prickly pear cactus (Opuntia humi- fusa). A deer-resistant garden includes a high percentage of these types of plants. See pages 32-33 for a list of deer resis-Bioretention seeding in Columbia, Missouri tant native plants.reduces maintenance costs associated withmowing, mulching, and weeding.For Erosion Control For Less MaintenanceSiltation is a main source of water pol- Compared with lawns and mulchedlution. Soil loss can be reduced by tree, shrub and perennial plantings,using plants with strong, deep roots in landscapes planted with appropriateplace of turf, rock or concrete. Plants native plants require less maintenance.hold the soil, absorb water and slow They require minimal watering (exceptthe flow of water over the surface. during establishment and drought peri-Replacing turf with native plantings is ods) and they need no chemical fertil-an effective way to help control erosion. izers or pesticides. Characteristics of native plants thatTo Create Wildlife Habitat reduce maintenance include:A native plant garden with a diversity • Longevity: plants that live forof trees, shrubs, perennials and grasses many decadesprovides food and shelter for insects, • Three to four-season interest: plantsbirds, amphibians and mammals that are apealing most of the yearthroughout the growing season. • Variable conditions: plants thatLeaving seed heads and plant structure tolerate a wide range of light andthroughout winter provides continuing moisture conditionsfood and shelter for many creatures • Small and compact: plants that areand provides opportunities to observe in scale with a given spacenature up close. • Weed elimination: plants that grow into dense groupings and eliminateFor Resistance to Deer Browse weeds • Seediness: plants that do not spreadDeer are adaptable and eat a wide vari- readily from seedety of plants. Forturately there are manynative plants that deer avoid. Deer See page 24 for a list of top performingrely on their sense of smell to deter- native plants that reduce the amount ofmine whether an area is safe and which maintenance.plants are desirable to eat. For instance,plants with aromatic foliage such as
6 Landscaping with Native Plants A Gardener’s Guide for Missouri Cost comparisons: This list provides many reasons to use native plants in a landscape, but Turf before you begin planting, think about • Average turf installation per what you want the landscape to do acre (seed): $3,000 for you. You may want to reduce time • Average turf installation per and money spent mowing a large acre (sod): $8,000 expanse of turf. Or you may want to • Annual turf maintenance per reduce the expense of installing annu- acre: $1,000 al flower beds. These numbers put the • Annual turf maintenance cost of mowing grass and maintaining for homeowner:$500 standard planting beds into perspec- tive. Native Prairie Seeding • Average prairie seeding per acre: $1,500 • Annual prairie maintenance per acre: $200 The proper handling of stormwater runoff is a significant issue for homeowners, neigh- borhoods and communities. Left: a rain garden planted with Missouri native plants at the Missouri Methodist Conference Center in Columbia, Missouri. Right: Missouri Botanical Garden bioretention best managment practice (BMP) planted with natives in the main entry parking lot (oak sedge (Carex albicans) in foreground).
7 Mulched Groundcover Planting• Average planting per 1,000 sq. ft. $2,500• Annual maintenance per 1,000 sq. ft. $200Standard Mulched Planting Bed• Average planting per 1,000 sq. ft. $3,500• Annual maintenance per 1,000 sq. ft. $400Native groundcovers require the leastamount of maintenance because theyestablish quickly, are long-lived, sup-press weeds and require little mulchonce established. Native groundcov-ers also are an excellent alternative A site plan of your property will help youto invasive wintercreeper euonymus, decide where to place gardens, walkways, patios and stormwater features.English ivy and periwinkle that haveescaped cultivation and invaded manynatural woodlands in Missouri. Indicate north, south, east, and west, soil types, existing vegetationSee page 26 for a list of native and patterns of shade and sunlight.groundcovers. Make copies of the drawing so various versions of the planningSite Evaluation process can be kept as the design changes. As possibilities are pulledMap the Area together, remember the saying “don’t fight the site.” For most con-Now that you’ve thought about ditions encountered, there is a list ofwhy to use native plants and what plants that will thrive there. It isyour goals are, it’s time to make simpler and less expensive to usea map. A map, drawn to scale, this approach than to alter the site.aids in determining plant numbersas well as placement and the amountof compost and mulch needed.Slope, drainage and potentialfor erosion should be noted andreviewed for a possible bioswale orrain garden. Indicate location of struc-tures, utility lines and traffic use.
8 Landscaping with Native Plants A Gardener’s Guide for Missouri Survey of Existing Vegetation canadensis), that thrive in dry, rocky soils but suffer in compost-rich soils. A plant survey of the area may reveal By considering your soil, its structure, remnants of the plant community fertility and pH, you will be able to that once existed on the site. These compile an appropriate plant list for remnant species are good sources for any soil type encountered. seed to use in establishing new land- scapes. For example, if native wetland grasses and forbs grow nearby or on Soil Fertility and pH the site, include those in the plant list. Keep a close eye on the ripen- Get a general analysis of your garden ing seeds of these plants for collect- soil with a basic soil test. Soil sample ing. The site may be covered with information forms are available at shrubs, vines or weedy vegetation. If University of Missouri Extension offices so, determine which vegetation should and online at www.extension.missouri. be removed. Identify trees and shrubs edu. When filling out the form select a that will remain and remove weaker general analysis. and undesirable species. Enlist the help of an arborist if you are unsure pH is a measurement of a soil’s acidity of which tree species are beneficial to or alkalinity on a scale where 7.0 is the overall design. neutral. Results below 7.0 indicate an acid (sour) soil, and soils above 7.0 are alkaline (sweet). Many plants do Sunlight well in one or the other environment, while a wide assortment thrive in the Determine the quality of light on the pH range of 6.5 - 7.5. Basic soil tests site. If shade exists, note when the also give a soil’s content of macronu- shade occurs. Afternoon shade or trients such as nitrogen, phosphorus dappled, occasional sunlight provides and potassium. A more complete soil a good environment for many savanna test yields levels of the micronutrients and woodland species. In contrast, hot in the soil (boron, magnesium, cop- afternoon or all-day sun is best suited per). to prairie, wetland and glade species, depending on soil type. Testing Water Infiltration to Determine Soil Types Soil To determine soil type and how quick- Many native plants are generalists; ly water drains through soil, do an they tolerate a wide range of soil infiltration test. First, dig a hole one types. However, there are some, such foot deep and eight inches wide. Fill as the glade coneflower (Echinacea it with water and observe how quickly simulata) or rose verbena (Glandularia the water disappears. Note: do infil-
9tration tests when soil is moist, the of this, clay soil has poor drainageday after a soaking rain or watering. and lower fertility. Clay soils often are described as being heavy. The charac-• If water drains within an few hours teristic color is reddish or grayish. the soil is a well-drained sandy or loamy soil. Select dry-loving native plants listed on page 32. Silty soil feels smooth and silky but• If it takes 24 hours or more to does not form a ribbon like clay. It drain, it is a poorly drained clay has particles much smaller than sand. soil, typical of where native wet- Fertility is slightly higher than sandy land species thrive. See chapter soil. It drains relatively well and has a two of this landscaping series: tan color. Rain Gardening and Storm Water Management for a list of appropri- ate plants. Sandy loam soil is considered the• Soils that drain in less than six ideal garden soil for the widest range hours are considered satisfactory of plants. It is sold as topsoil. The soil for growing most native plants. color is dark-brown and particle size varies. It is among the healthiest of soil types since it is well-draining withSoil Texture ample air spaces, has good organic content and fertility and has an abun-Another way to determine soil type is dant population of beneficial soilby feeling it with your hands. Hold a organisms.small wet piece of soil in your handand rub it between your thumb andindex finger. Soil StructureSandy soil has obvious sand particles Soil structure indicates the effectthat feel and look like sand. It drains soil has on the movement of water,well because of a large particle size amount of air in the soil and howthat is irregularly shaped. It feels well roots are able to penetrate intocoarse and doesn’t compact easily. the soil. It works in conjunction withThis soil type has low fertility because soil texture and is easy to deter-of its low organic content. Soil color mine. A simple way is to form a balltypically is light tan. of damp soil in your hand by squeez- ing it. If you can’t make a ball, the soil is sandy. If it is crumbly and hasClay soil feels sticky and forms rib- dark color, it is a sandy loam. Claybons when forced between your soil remains in a ball. Soil structurethumb and index finger. It has micro- can be improved with the addition ofscopic, flat-shaped particles. The compost. This increases particle sizeshape and size of clay particles con- and encourages beneficial soil-bornetribute to compaction, with little space organisms.for air or water movement. Because
10 Landscaping with Native Plants A Gardener’s Guide for Missouri Soil Moisture patterns and storm water flow during and after a heavy rain. Note sunny and The moisture level in soil is determined shady areas and where water drains by a combination of topography and and puddles. The plant list section on soil structure. For example, a low-lying pages 24-34 groups plants by sunlight, area with organic or clay soil stays soil types and tolerance to flooding and moist for long periods of time. Wetland drought. species are an appropriate choice for this situation. The converse is a rocky Here is a list of landscape situations and soil with low organic content at or near solutions that will help you select the the top of a rocky slope. These sites right plants for your garden: dry quickly after a rainfall. In this case, upland prairie, savanna and glade spe- • If you have limited time to garden cies are the best choices. keep the landscape style simple and use native groundcovers. Reduce Supplemental watering may be neces- plant diversity and mass single spe- sary until plants are established and cies in larger spaces. Native ground- mature. covers are an excellent alternative to high-maintenance turf. They cover areas quickly, suppress weeds and reduce amounts of mulch needed. • If you like to spend time in the gar- Plant Selection den, you can incorporate higher plant diversity, more garden fea- tures and a more complex design Right Plant, Right Place layout. This requires increased time, labor, plants and maintainance. Plants flourish with minimum mainte- • If you have exposed boulders, rocky nance when appropriately chosen for a or gravely soil, or plants that grow certain location. For small gardens and sparsely, choose plants that grow on landscapes, determine sunlight and soil rocky glades. moisture conditions by observing sun • If you have hard clay, select plants Low-maintenance native groundcovers are used in simple massed plantings. When fully mature they suppress weeds and reduce the amount of mulch needed. Left: yellow fox sedge (Carex annectans) Right: prairie alumroot (Heuchera richardsonii)
11Plants growing in nature give us clues as to where they may be suited in a man-madelandscape like a rain garden. Left is yellow-fruited fox sedge growing in a sunny creekbottom. Right is cardinal flower growing at the edge of a shady creek. that tolerate low fertility and poor including prairie, woodland, wetland, drainage. etc. Regional plant field guides typi-• If your garden is in a low, wet cally describe general plant habitats area, create a rain garden. in the front of the book. Once you• If whitetail deer are a problem, determine your habitat type(s), begin select native plants they avoid. selecting appropriate plants. Not all plant species are available for sale soSee pages 24-34 for detailed lists of it is best to refer to nursery catalogsplants for various garden conditions. as you select plants by habitat.Select Local Ecotype Plants Sunny EnvironmentsThese plants originate from wild popu- Prairieslations in your region, which meansthey are adapted to Missouri’s climate.This does not mean the plants youpurchase come directly from the wild.Wild harvested plants should be avoid-ed because they deplete native plantpopulations. Local ecotype plants willoutperform non-local ecotype plantsin most cases because they are accli-mated to Missouri’s soils, weather andpests. A prairie is an ecosystem of grassesPlants for Larger Landscapes with herbaceous forbs. Few trees or shrubs exist in this habitat. TypicalYou may be able to select plants by prairie plants include Indian grassidentifying the original habitat type (Sorghastrum nutans), big bluestem
12 Landscaping with Native Plants A Gardener’s Guide for Missouri (Andropogon gerardii), rattlesnake and aromatic aster (Aster oblongifolius). master (Eryngium yuccifolium), aster, Many species encountered in dry upland goldenrods and many Silphium spe- prairies also are found in glades. cies. Some prairies have wet soils and are host to plants such as prairie cord grass (Spartina pectinata), wild bergamot Wetlands (Monarda fistulosa) and marsh milkweed (Asclepias incarnata). Upland prairies exist where the bedrock is shallow and soil is dry and glade-like. Shorter plants predominate, such as little bluestem (Schizachyrium scoparium), sideoats grama (Bouteloa curtipendula) and but- terfly milkweed (Asclepias tuberosa). Glades Missouri has an abundance of wetlands, from river edges to lake shores and wet meadows. The list of plants well-adapted to these alternating wet and dry condi- tions is extensive. In addition, there are many plants that flourish in permanently wet areas and in ponds. Soil types range from clayey to sandy loam and are sub- ject to fluctuating moisture levels. A few representative plants include the mighty swamp oak (Quercus bicolor) and bald cypress (Taxodium distichum), beauti- Thin, rocky topsoil combined with out- ful irises such as blue flag (Iris virgi- croppings of shallow bedrock creates this nica) and copper iris (Iris fulva) as well desert-like environment. Glades typi- as cardinal flower (Lobelia cardinalis) cally are found on south- and southwest- and rose mallow (Hibiscus lasiocarpus). ern-facing slopes and ridgetops in the Sedges (Carex spp.) and rushes (Juncus Ozark Highlands. These areas are hot spp.) compose a large percentage of the and sunny because the shallow, well- plant list. Wetlands offer a wide diversity draining soil does not support growth of of plants, birds, mammals and insects. large trees. Sunny south or west-facing Frogs and other amphibians are heard slopes with thin soil and exposed rocks and seen frequently. Wetland plant lists are areas in your landscape where glade are useful for rain gardens, bioswales plants will thrive. When planted in rich and low areas that remain wet for long soil, common in many gardens, glade periods. plants deteriorate and die. Plants found in a glade environment include rose ver- bena (Verbena canadensis), Missouri eve- ning primrose (Oenothera macrocarpa)
13Shady Environments Riverbottom and North-sloping ForestsUpland Savannas Riverbottom and north-sloping wood-Many areas of Missouri were savannas lands tend to have soils that are richwith widely spaced trees, predominant- in organic matter and hold moisture.ly oak and hickory species. Savannas The tree canopy is heavy and produc-are dominated by grass species and es medium to dark shade, with a thickare interspersed with forbs (herbaceous understory. Typical species includeflowering plants) that fill the wood- ferns, wild geranium (Geranium macu-land floor. The quality of light is bright, latum), Virginia bluebell (Mertensiadappled shade with areas that receive virginica) and wild sweet Williamsunlight for short periods. Typically (Phlox divaricata). Specific speciessavannas occupy the higher and drier vary according to where they existsoils of upper slopes and ridges of hills in the woodland - top of ridge versusand are maintained with prescribed fire bottom of hill or north versus southor annual mowing. The park-like setting facing slopes.of suburban properties are reminiscentof savannas. Plants such as smoothhydrangea (Hydrangea arborescens), Planning and Site Preparationconeflower (Echinacea purpurea), blaz-ingstar (Liatris scariosa) as well as Layout and Estimating Squaremany asters and goldenrods are appro- Footagepriate choices for savanna-like settings. Outline the area to be planted with a hose or rope. It is easier to move a hose or line than to make changes after dig- ging has occurred. Stakes are another way to create an outline. Once you are happy with the layout, measure and multiply the length and width to get a rough square footage. Most spaces have round edges so keep in mind that this is a rough estimation.
14 Landscaping with Native Plants A Gardener’s Guide for Missouri Remove Existing Vegetation Removal of existing vegetation is impor- tant for the successful establishment of new plants and can be done in a number of ways. For killing weeds on large properties, refer to Chapter One – Seeding a Tallgrass Prairie. For identi- fication and removal of invasive species, refer to Chapter 3 - ID and Control of Invasive Species. For smaller properties, the first step Estimating Plant Quantities and is to mow or string-trim tall weeds Spacing down to 4-12 inches. The second step includes one or more of the following If your garden layout is 10 feet by 10 techniques. feet you have 100 square feet of space (10x10=100). If you choose to plant on Herbicides Read herbicide labels before 12-inch centers, you need 100 plants. use. Apply a glyphosate herbicide such as Roundup. Use Rodeo instead of Plant Quantity Calculator Roundup if the area is near a pond or creek. Less herbicide is required if veg- Spacing in Inches etation has been mowed short. In two weeks, the vegetation will brown and 8” 12” 18” 24” 36” die. Leave the dead stubble to prevent erosion, especially on slopes. It also will decay and add organic content to the 50 100 50 22 12 5 soil. Shredded leaf or bark mulch may 100 225 100 45 25 11 be applied over the dead vegetation. 150 350 150 67 37 16 200 450 200 90 50 22 250 550 250 112 62 28 300 675 300 135 75 33 400 900 400 180 100 44 500 1100 500 225 125 55 600 1350 600 270 150 66 700 1550 700 315 175 77 800 1800 800 360 200 88 900 2000 900 405 225 99 1000 2250 1000 450 250 110 Left colum is total square feet. There are a number of plant calculators on the internet. www.classygroundcov- Always wear safety glasses or goggles, ers.com is one of the easiest to use. gloves and protective clothing when applying herbicides. Read herbicide labels before use.
15Use a thick layer of compost or wood backfill with topsoil. This eliminateschips over existing vegetation to air pockets and drought-relatedsmother it. In smaller gardens, a layer mortality and reduces establishmentof newsprint can be used before mulch- time.ing. It takes a couple of months for thevegetation to die. This method workswell for small to medium size gardens. Soil Compaction and GradingOnce undesired vegetation is killed, donot till in uncomposted leaves, bark or Before grading soil or planting, it iswood chips as they will cause the new important to contact the Missouri-1 Callplants to turn yellow or die. System to locate underground utilities. Call 1-800-DIG-RITE three days beforePut clear plastic over the mowed breaking ground. They will mark under-vegetation, and sunlight will create ground utilities with colored spray paintheat that kills the vegetation. However, and flags.microorganisms in the upper layer ofsoil are affected adversely so add com- Avoid compacting soil with heavypost and earthworm castings to the soil equipment or foot traffic. Compactedto replenish the microbial populations. soil drains poorly, has low oxygen con- tent and is difficult to plant in. If soilRemove sod with a desodding shovel or is compacted, loosen the soil beforemachine. The top few inches of roots planting. Severe compaction mayand soil are removed, exposing the require digging deeply with shovels orunderlying soil. in large areas with a mini excavator or backhoe. This is necessary for proper drainage. Then till soil to create a looseSoil Preparation soil that is easy to work with.Amending soil should be done only Final soil grading typically is done onunder the most difficult circumstances small areas by hand with stiff gar-because there are native plants that den or grading rakes after tilling. Ontolerate a wide variety of tough soil large areas this is done with a skid-conditions. steer-mounted tiller or soil conditioner. During the grading process, tough clods• Severe clay subsoil that is remain- of dirt, clay, rocks, roots and stems ing after construction should have are raked out and removed. Steep soil a minimum of 3 inches of topsoil grades require the application of ero- added and tilled into the surface. sion blankets.• Severely compacted topsoil should be loostened by hand with a shovel or with a backhoe or mini-excavator Stabilizing Steep Slopes for larger areas.• Fertilizing is not normally recom- There are several brands of erosion mended unless you have clay sub- control blankets available in garden soil and choose not to add topsoil. centers. They typically are made of• If planting in clay subsoil, remove straw, wood shavings, coconut fiber or soil unearthed while planting and
16 Landscaping with Native Plants A Gardener’s Guide for Missouri Planting Planting Seasons Spring and fall are the best times to install native plants, with spring being the first choice. Containerized plants and divisions establish quickly because soil is cooler and moister. That said, you may plant containerized plants in Unroll erosion control blankets from top of summer as long as you water regularly. slope to bottom and overlap edges to attain If water is not available, plant between complete coverage. Pin down blankets late February and April. securely. jute and are woven into a plastic mesh that should be biodegradable. Avoid Lay Out Plants non-biodegradable or permanent fabrics because birds and reptiles get tangled in Lay out plants (in their containers) the mesh. on the ground to attain even spacing before planting. 0 – 10% slope: 2 foot or less drop in a 20 foot distance. Gentle slopes are Use a grid pattern similar to this when ideal and easy to work with and do not planting larger areas and groundcovers. require erosion control fabric. X X X X X X 10 – 20% slope: 4 foot or less drop in a 20 foot distance. Steeper slopes can X X X X X present a challenge and use of erosion control fabric should be considered. X X X X X X Above 20% slope: 5 foot or less drop in a 20 foot distance. Once the percent In hot sun keep plants watered as most slope is above 20%, erosion control is plastic pots are black and absorb heat. recommended. Now is the time to rearrange plants to attain the best spacing. (See graph below) 0 0 – 10% 2 ft. 10 – 20% 4 ft. 20% plus 6 ft. 20 ft. length
17Planting in the Soil Mulching New PlantingsPlant first and then mulch. This Twice-ground leaf compost is rec-ensures plant roots are in the soil and ommended for mulching perennialsnot just in the mulch. and grasses. Shredded hardwood (or cedar) bark mulch is recommended forInsert the plant so the potting mix is trees and shrubs. Use these recom-not exposed to the mulch or air, so mendations to prevent over-mulchingthe rootball will not dry out. Cap the or burying plants too deeply in mulch:potting soil with a thin layer of naturalsoil to prevent moisture loss. Deep Cell Plugs....1.5 inches Quart Pots...........2 inchesWhen planting in hard clay soil, have Gallon Pots..........2.5 inchesa bucket or wheelbarrow of rich, loos- Tree/Shrubs.........3 inchesened topsoil handy to backfill plantingholes. Backfilling with hard clay clods Do not incorporate mulch into theleaves air pockets that lead to des- soil as this leads to poor plant perfor-sication or plant death. You may have mance and/or death.good topsoil on your property to bor-row or you may have to purchase top-soil from a garden center. Watering New PlantingsIf you mulch the planting area before Water new plantings immediately!planting, do not exceed the mulch Don’t wait for rain since weather can’tdepths listed below and do not leave be predicted from hour to hour.soil on top of the mulch as thisencourages weeds. Also be sure that During the first three weeks, waterplant roots are inserted in soil and not plantings every four days for aboutin mulch. 60 minutes (the equivelant of about 1Left: Carefully remove plant from container. If roots are spiraling around insidethe pot, cut the roots to prevent further spiraling. Middle: Remove loose pottingsoil from the top of the potting soil ball. Insert plant so the top of the potting soilis level or just below the top of the topsoil and fill in with loose topsoil. Lightly cappotting soil with a thin layer of topsoil. Right: Firmly press down plant to remove airpockets. Cover topsoil with 1-2 inches of mulch and water immediately.
18 Landscaping with Native Plants A Gardener’s Guide for Missouri inch of rainfall). A one-hour watering will soak more deeply into the ground Maintenance than daily 15-minute waterings. In summer increase frequency to every There is the misconception that three days. native landscapes require little or no maintenance. In reality, some native After three weeks reduce frequency to gardens require a lot of maintenance once per week until plants are estab- and some don’t. This list describes lished. Plants are established when what makes a native landscape low- roots have grown out of the container maintenance and why: soil and into the native soil to a depth of two to four inches. This normally • Plants that are long-lived do not takes three to four months for peren- need replacing. nials and grasses and six months • Plants that are selected properly for trees and shrubs. With trees and for a site will thrive. shrubs, the larger the root ball the • Plants that have few pest prob- longer it takes to become established. lems require no chemicals. Extremely large trees may take years. • Plants that are compact and clump-forming work well in small When plants are fully established, places and don’t flop over. watering is only necessary during dry • Plants that sucker to form solid or drought periods during summer. ground-cover fill large spaces quickly, keep weeds out and require little mulch. Planting Seed • Plants that do not spread agres- sively from seed reduce weeds. It is less expensive to plant large • Plants with clean, dense foliage areas with seed than with plants. three to four seasons of the year Seeded areas look natural and are prevent weeds and require little usually in sunny areas (prairie), shady mulching. woodlands (savanna), or wet areas (wetlands, rain gardens, bioretention If your goal is to reduce maintenance, or detention basins). When seeding be keep the landscape style simple and certain weeds are eliminated, do not use native groundcovers. Reduce plant till the soil, sow seed in early winter diversity and group single species in and keep the seeding mowed to six large masses. Native groundcovers are inches during the first growing season. an alternative to high-maintenance It takes about three years for most turf and flower beds. They cover areas seedlings to mature and flower. quickly, suppress weeds and reduce the amount of mulch needed. Please read Chapter One, Reconstructing a Tallgrass Prarie for As with all gardens, a new plant- a detailed description of how to sow ing requires attention as the plants seed. become established. Once root sys- tems are well developed, supplemen- tal watering should be minimal or only in periods of drought.
19Weed Control down to subsoil clay after new con- struction. These clay soils are impos-It is likely weeds will grow in newly sible to dig in when dry. In theseplanted areas the first and second extreme situations add a minimum ofyears. Control them by handpulling three inches of topsoil before planting.or spot spraying with a glyphosphateherbicide such as Roundup. If youhave nut sedge, hand-pull repeatedly An application of one to two inches ofuntil it is gone or use the herbicide compost each fall helps maintain anSedgehammer. adequate level of fertility and organic matter in the soil, which reduces orBy the second or third year, plants are eliminates the need for fertilizer.more established and able to crowdout weeds. Weeding becomes minimalas the garden matures. Annual appli- Insect Problemscations of compost and mulch in lateautumn help suppress weed growth In general, native plants are notand make handpulling much easier. affected by insect damage. There are exceptions, however. Japanese beetles may devastate native roses, hazel- nut and wild grapes in some years. Dogwood sawflies denude swamp dog- wood, but only in some years. It is only a matter of time before beneficial insects move in and control the prob- lem naturally. Developing a tolerance for small amounts of damage and an under- standing of the interaction of beneficial insects eliminates the need for pest control. There is a host of desirable caterpillars that nibble native plants. Monarch caterpillars eat milkweed leaves, zebra swallowtails eat pawpaw Yellow nutsedge is a common gar- leaves and giant swallowtails eat wafer den weed that is difficult to control by ash shrubs. All of these turn into beau- hand. Hand pull small infestations or tiful butterflies. spray the herbicide Sedgehammer for large-scale control. To control mosquitos use a diversity of native plants in and around water edges. This will attract native aquaticFertilization insects and frogs that eat mosquito larvae.Fertilizer is not necessary with mostnative landscapes. The exceptions aresites where topsoil has been removed
20 Landscaping with Native Plants A Gardener’s Guide for MissouriMulching Shredded hardwood or cedar barkMulch gives gardens a clean, tended mulch is also commonly used andand intentional appearance. Other available. Cedar lasts much longerbenefits include preventing loss of than hardwood but costs more. Oncesoil moisture, controlling soil tem- rained on, it tends to bind togetherperature and suppressing weeds. and will not migrate. It is recom-Mulch may be applied from late fall mended for use in rain gardens.through spring. In areas where youwant to encourage seed germina- River gravel mulch comes in varioustion (woodlands, for example), apply sizes, from pea-sized gravel to three-mulch after seeds have germinated in inch rock. A medium size of one orspring and are tall enough to trans- two inches works best in rain gardensplant. or where storm water will be flowing. It is heavy to move around.Never till mulch into topsoil becausemulch is not composted. As it breaks Pine bark chip mulch has largedown it starves plants of nutrients. pieces that migrate on slopes andMulch must be fully rotted (black in float. It is recommended for use oncolor, the consistancy of sawdust and flat ground.have no heat) before it can be incor-porated into topsoil. Natural tree leaves raked up and reused as mulch save money but doTwice-ground composted leaf not look clean or intentional in plant-mulch is one of the more commonly ing beds. They are best used in natu-used mulches and is readily available ral wooded settings.from compost suppliers or gardencenters. It is delivered warm or hot Wood chips from a tree chipper areand has a slight to strong sour smell coarse, uneven and do not look asbecause it is not composted com- clean as ground mulches. They workpletely. This mulch can float so is not well, however, and are economical.recommended for use near stormwa-ter flows. Left: Shredded hardwood bark mulch binds together to resist washing away. Middle: River gravel mulch will not migrate where water flow is a problem. Right: Wood chip mulch is inexpensive or often free but migrates and may float away where water flow occurs.
21Pruning growth is removed and old stems are kept. Dogwood, fringetree, south-Pruning involves the use of hand ern blackhaw viburnum, green haw-pruners, hand saws, lopers, or thorne, serviceberry, pagoda dog-shears. Here are some reasons to wood and buckeye benefit from thisprune. treatment.• To remove damaged branches. If a shrubby screen-like appearanceIce and wind storms may cause bro- is desired, older trunks are removed,ken branches on trees and shrubs, leaving young stems. Hazelnut,that should be removed before they rough-leaved and gray dogwood andcause harm to people or property. sumac are used in this treatment.When pruning tree limbs, be cau-tious as limbs may fall at any time.Contact a certified arborist if you are • To rejuvenate shrubs. Shrubsunsure about safety issues. such as wild hydrangea, Alabama snowwreath, golden currant, and• To remove suckers and water Missouri gooseberry benefit from asprouts. Suckers are fast-growing rejuvinating pruning every three tosprouts that emerge from the ground five years. First trim back shrub byat the base of a tree or shrub. Water 40-60% with shears. Then removesprouts are similar but emerge from one third of the old canes to thea stem or branch. Both are removed ground with hand pruners.because they give a messy appear-ance and increase disease problems.They are removed with hand prunersor hand saws on trees like hawthorn,viburnum, fringetree and dogwood.• To shape woody plants. Asyoung trees, shrubs and vines beginto mature and gain height, lowerbranches may be pruned off to cre-ate space for planting beds under-neath. Wide-arching side branchesare pruned when they grow out ofcontrol. While this can be done atanytime, it is best done just afterflowering to ensure blooming the When using hand pruners the cuttingnext year. blade (black) is always on the side of the cut that remains. The anvil (silver) is toMulti-stemmed trees and shrubs are the outside. Always keep the blade sharp and be careful not to cut yourself. Handpruned either to maintain an upright pruner cuts are the leading cause of inju-tree or low-bushy appearance. To ry in most gardens.create a tree-like look, new vigorous
22 Landscaping with Native Plants A Gardener’s Guide for Missouri • Thin growth. Trees and shrubs growing in full sun often develop Deadheading also prevents reseed- dense branching that requires thin- ing. If reseeding is a problem, ning. The same tree, growing increase mulch frequency and depth in shade, tends to remain open. or remove the reseeding plant. Keep Remove all crossing, rubbing, dead in mind that birds and small mam- or damaged stems in the interior mals depend on seeds for winter of the plant and work outward. It food. Stop deadheading in late sum- is desirable to open views into the mer to allow late crop seeds to ripen. center of a tree or shrub to reveal interesting bark and branching. • Control height. Spring top- Hornbeam, southern blackhaw vibur- pruning (or spring haircuts) of the num, spicebush, red buckeye, red- taller, late-summer-to-fall-blooming bud, pagoda dogwood, yellowood, perennials and grasses reduces and witchazel benefit from this treat- plant height and prevents flopping. ment. Remove the top 40-60% of spring growth late April through mid-May, • Promote reblooming. using hedge shears or hand pruners. Deadheading (removal of spent Plants pruned this way become multi- flowers) on perennials and annuals branched, fuller and shorter overall. stimulates more blooming. Be sure to Flowering species that respond well remove faded flowers before seeds to this include aster, Joe-Pye weed, ripen since ripe seed is a signal to sneezeweed, rose mallow, turtlehead, the plant to stop blooming. This method works well on Missouri eve- garden phlox, goldenrod, and iron- ning primrose, rose verbena, core- weed. The grasses include big opsis, black-eyed Susan, and native bluestem, Indian grass, switchgrass, annuals such as sneezeweed and cordgrass, and eastern gama grass. palafox. When pruning medium-sized branches, always make a small undercut first (left) and then finish the cut with an overcut (right). This prevents the bark from tearing downward when the branch falls.
23 time). • Layout the garden areas and related elements of the site and calculate square footage for each portion individually. This number helps you predict the number of plants or materials needed. • Remove weeds and undesirable growth by hand, with Round-up (glyphosphate) or by layering newspaper and covering it with mulch. • Grade and amend soil if neces- sary; then mulch if you will not beTaller, late-summer blooming perenni- planting right away.als and grasses may be sheared back by • Autumn is the second best time40-60% in late May to control height and to plant. Perennials and grassesprevent flopping. can be planted in September and October. Plant quart size contain- ers or larger. Trees and shrubs may be planted from September through November. • Mulch new plantings immediately as mulch helps maintain soil mois- ture and steadies soil tempera-Typical Garden Schedule ture. • Water new plantings immediately.Summer and Fall - Year 1• Map out the site, noting existing Winter - Year 1 and future use, traffic patterns, utilities, trees, water flows, poorly • October through March is a good drained areas, wildlife use, desir- time to construct patios, paths able and undesirable views. and walls.• Assess the site for drainage, soil • Fall-planted trees and shrubs may type, sun, shade and utilities. need watering during severely dry• Choose the site, the plant palette periods. (plants you want to include), the landscape style and layout for the garden (you likely will be selecting Spring - Year 2 hardscape features like pathways, fences, patios, water features, • Spring is the best time to plant. walls, containers, outdoor pizza Planting may begin in mid-March ovens and other features at this and continue until the end of May.
24 Landscaping with Native Plants A Gardener’s Guide for Missouri If you plant after June 1st, water periodically during planting and Plant Selection Guide then every three days until plants are established.• Remove weeds as they appear. Top Performing Native Plants• Water as needed. for Landscaping• Top-prune perennials and grass- es late April through mid May to Based on: reduce flowering height and pre- vent flopping. • 3-4 seasons of interest • long life expectancy • compact form or slow growthSummer - Year 2 • availability from nurseries• Be vigilant and remove weeds as they appear. Full Sun• Provide a deep watering when needed rather than frequent, shal- Grasses and Sedges: Carex albicans (oak sedge) low watering. Carex annectens (yellow-fruited fox• Summer planting is not recom- sedge) mended due to heat and unpredict- Carex muskingumensis (palm sedge) able rainfall. Sporobolus heterolepis (prairie dropseed) Perennials:Fall/Winter - Year 2 Amsonia illustris (shining bluestar) Asclepias tuberosa (butterfly milkweed)• Continue to be vigilant and remove Aster oblongifolius (aromatic aster) winter weeds as they appear. Baptisia sphaerocarpa (yellow wild indi-• Water newly planted trees and go) shrubs by hand if winter drought Callirhoe involucrata (purple poppy mal- occurs. low)• Reapply mulch to thin areas. Heuchera richardsonii (prairie alumroot)• Be careful to not mulch where you Iris fulva (copper iris) want plants to spread by reseed- Pycnanthemum tenuifolium (slender mountain mint) ing. This is the trick to getting Rudbeckia fulgida (orange coneflower) woodland plants like wood poppy, Virginia bluebells, blue-eyed Mary, Small Flowering Trees and Shrubs: wild geranium, bloodroot and oth- Amelanchier arborea (serviceberry) ers to spread. Callicarpa americana (beautyberry) Cercis canadensis (redbud) Crataegus viridis (green hawthorn) Hydrangea arborescens (wild hydrangea) Ilex verticillata (winterberry holly) Ribes odoratum (golden currant)
25 Heuchera Americana (American alum-Part Shade root) Iris cristata (dwarf crested iris)Aster oblongifolius (aromatic aster) Polygonatum biflorum (Solomon’s seal)Carex albicans (oak sedge) Solidago flexicaulis (zig-zag goldenrod)Carex eburnea (ivory sedge) Spigelia marilandica (Indian pink)Carex grayii (bur sedge)Carex muskingumensis (palm sedge) Small Flowering Trees and Shrubs:Echinacea purpurea (purple coneflower) Amelanchier arborea (serviceberry)Heuchera americana (American alum- Callicarpa americana (beautyberry)root)Heuchera richardsonii (prairie alum- Cornus alternifolia (pagoda dogwood)root) C. florida (flowering dogwood)Polygonatum biflorum (Solomon’s seal) Dirca palustris (leatherwood)Solidago flexicaulis (broad-leaved gold- Hamamelis virginiana (Eastern witchenrod) hazel)Spigelia marilandica (Indian pink)Small Flowering Trees and Shrubs:Amelanchier arborea (serviceberry) Native GroundcoversAronia melanocarpa (black chokeberry)Callicarpa americana (beautyberry)Carpinus caroliniana (hornbeam)Cornus florida (flowering dogwood)Hamamelis vernalis (Ozark witch hazel)Hydrangea arborescens (wild hydrangea)Ilex verticillata (winterberry holly)Ribes odoratum (golden currant)ShadeFerns:Adiantum pedatum (Maidenhair fern) The 12-inch native groundcover field sedge (Carex praegracilis) growing in a solidAthyrium pycnocarpon (silvery spleen- mass at Shaw Nature Reseve reduceswort) maintenance, tolerates poorly drained clayOnoclea sensibilis (sensitive fern) soils and suppresses weeds.Polystichum acrostichoides (Christmasfern) *Plants that spread rapidly by rhizomesGrasses and Sedges: and develop into large colonies. TheseCarex albicans (oak sedge) species require large areas and contain-Carex eburnea (ivory sedge) ment.Carex grayii (bur sedge)Carex muskingumensis (palm sedge) ShadePerennials: Grasses & sedges:Asarum canadense (wild ginger) Carex albicans (oak sedge)Geranium maculatum (wild geranium) C. eburnea (ivory sedge)