Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Control of Invasive Non-Native Plants


Published on

In the next century, the greatest threat to our native plants and the wildlife species that depend upon them may well come from other plants.

  • Be the first to comment

  • Be the first to like this

Control of Invasive Non-Native Plants

  1. 1. In the next century, the greatest threat T housands of plant species have been brought to North American in the past three to our native plants and the wildlife species that centuries. Most are well-behaved, depend upon them rarely penetrating natural areas. may well come from other plants. Several hundred, however, have no natural controls here, and are able to out-compete and gradually displace our native plants, even deep in forests and undisturbed Control of Invasive ecosystems. Variously called alien, introduced, Non-Native Plants or exotic, these non-natives are highly invasive. A Guide For Gardeners and Homeowners in the Mid-Atlantic Region Some of these plants were brought here intentionally, for their medicinal, ornamental, or food For more nature habitat information value. Others hid in soil, crop seed, Visit these helpful websites: or ballast. A Plants Home A Birds Home Most came from other A Homesteaders Home continents, but a few have spread from other parts of the U.S. In each region, different species are better adapted and therefore pose a greater threat. This guide is for the piedmont and inner coastal plain regions of Maryland, northern Virginia, the District of Columbia, Delaware, and southeastern Pennsylvania. Many of the plants in this guide are popular, even beloved, landscape plants, but it is now clear that they pose a threat to our environment. If you cannot effectively contain these plants within your property, by clipping seeds, fruits, or runners, please consider removing them. It is a difficult decision, but each of us has a responsibility not to damage the local ecosystem that cleans our air and water, stabilizes the soil, buffers floods, and provides food and shelter for innumerable species besides our own.© WindStar Wildlife Institute Page 1 A Plants Home
  2. 2. Each of the non-native plants free. If so, it has no natural Invasive, Non-Native Shrubs in this guide significantly reduces controls here. Do not plant it Multiflora Rose ( Rosa the number of plant and animal if it can spread out of the multiflora), formerly recommended species on any site it invades. garden. for erosion control, hedges, and wildlife habitat, becomes a huge When evaluating exotic plants s Does it have the ability to kill shrub that chokes out all other for your garden, ask these or suppress growth of vegetation and is too dense for questions: surrounding plants by shading many species of birds to nest in, them out, chemically poisoning though a few favor it. s Does it naturalize or self-sow. them, or out-competing them How far does it spread. Are for food and water. (Norway In shade, it grows up trees like a the seeds spread by wind or maple, a common landscape vine. It is covered with white water. tree, is a prime example.) If flowers in June. (Our native roses If so, don‘t plant it unless so, you don’t want it in your have fewer flowers, mostly pink.) you are prepared to remove all garden anyway! seeds, every year. Distinguish multiflora by its This guide lists garden plants size, and by the presence of very s Is it a wildlife food plant. If the and weeds which are already hard, curved thorns, and a fringed answer is yes, wildlife will causing significant changes to edge to the leaf stalk. spread it to woods and natural areas in the Mid-Atlantic. wetlands. In other words, Control: (1) – pull seedlings, dig these are plants to avoid. Measures for controlling each out larger plants at least 6" from Plant natives instead. species are indicated by number, the crown and 6" down; (4) on e.g., (3), in the text, and explained extensive infestations; (10) or (11). s Is it a rapidly spreading on page 9. ground cover. If so, don’t It may remain green in winter, so plant it adjacent to open The suggested alternatives are herbicide may be applied when space. native plants, well adapted and other plants are dormant. For needing little care, attractive to foliar applications, mix Rodeo with s Is it low maintenance – hardy, birds and butterflies, and an extra sticker-spreader, or use tolerant of drought or important part of the food web Roundup Sure Shot Foam on small flooding, shade-tolerant, pest for our indigenous species. plants. Recommended Native Shrubs Spicebush ( Lindera benzoin), which is covered with tiny yellow flowers in March, is our most common native shrub. It needs rich soil, as does Strawberry bush (Euonymus americanus). Maple-leaf viburnum ( Viburnum acerifolium) is suited to dry shade and thinner soil, while the arrowwoods (Viburnum dentatum, V. recognitum, V. nudum) grow in moist soil. Wild hydrangea ( Hydrangea arborescens), parent of some cultivated varieties, is a somewhat vining shrub. Highbush blueberry (Vaccinium corymbosum, the parent of cultivated blueberries) and Lowbush blueberry (V. vacillans ) need very acidic soil. They tolerate shade but fruit best in sun. Both turn red in fall. Multiflora Rose© WindStar Wildlife Institute Page 2 A Plants Home
  3. 3. Bush Honeysuckles ( Lonicera spp.), including Belle, Amur, Morrow’s and Tatarian honeysuckle. (In our region, assume that any honeysuckle is exotic unless it is a scarlet- flowered vine.) Bush honeysuckles create denser shade than native shrubs, reducing plant diversity and eliminating nest sites for many forest interior species. Control: (2) on ornamentals; (1); Garlic Mustard on shady sites only, brush cut in early spring and again in early fall (3); (4) during the growing The Most Invasive prevent it from setting seed (3). season; (7); or (10) late in the Non-Native Weeds Use glyphosate (11) or herbicidal growing season. Garlic Mustard (Alliaria soap (less effective) on large petiolata, A. officinalis), a white- infestations. Follow-up with (5) in flowered biennial with rough, spring. Other Ornamental Shrubs scalloped leaves (kidney, heart- or Japanese Spiraea (Spiraea arrow-shaped), recognizable by Mile-a-minute Vine, Devil’s Tail japonica). Control: (1); (2); (3), the smell of garlic and taste of Tearthumb ( Polygonum (7), (10), or (11). mustard when its leaves are perfolatum), a rapidly growing crushed. annual vine with triangular leaves, Privet (all Ligustrum species). barbed stems, and turquoise Control: (1); (7) or (10); or trim off Control: Pull before it flowers in berries in August which are spread all flowers. Do not cut back or spring (10) removing crown and by birds. It quickly covers and mow. roots. Tamp down soil afterwards. shades out herbaceous plants. Once it has flowered, cut (2), Burning Bush, Winged being careful not to scatter seed, Control: same as for stilt grass. Euonymus, Winged Wahoo, then bag and burn or seed to the (Euonymus alatus), identified by landfill. (11) may be appropriate in Japanese Perilla, Beefsteak wide, corky wings on the branches. some settings. Plant ( Perilla frutescens ). Sold as a salad plant, this member of the There is another species called Japanese or Vietnamese Stilt mint family is extremely invasive by Burning bush, E. atropurpureus, Grass, Eulalia (Microstegium wind-borne seeds. Recognize it by which is indigenous to the vimineum) can be identified by its the odd odor, supposedly like raw Appalachians, and a piedmont lime-green color and a line of beef, when you rub it. euonymus called Strawberry bush silvery hairs down the middle of (E. americanus ). the 2-3" long blade. It tolerates Control: (1); (2); (10) or (11). sun or dense shade and quickly Control: (1); (7) or (10); or trim invades areas left bare or Spotted Knapweed ( Centaurea off all flowers. disturbed by tilling or flooding. maculosa) a biennial with thistle- like flowers. Japanese Barberry (Berberis Control: Easily pulled in early to thunbergii), red and green mid-summer (1) – be sure to pull Canada Thistle, Bull Thistle varieties. before it goes to seed. If seeds ( Cirsium arvense, C. Vulgare ). have formed, bag and burn or send Exotic thistles are far more Control: (1); (7) or (10); or trim to landfill. Mowing weekly, or when common than native ones. If you off all flowers. it has just begun to flower may cannot identify the species, it is© WindStar Wildlife Institute Page 3 A Plants Home
  4. 4. Invasive Wetland Plants used, cut annually in late July to has spread from gardens to A number of ornamental plants reduce spread. carpet our flood plains with small once recommended for water yellow flowers in spring. gardens or moist garden soil have Giant Reed (Arundo donax ) spread to our riverbanks, flood chokes waterways from Virginia It comes up in winter, giving it a plains, and wetlands. south. It can grow 20 tall. head start over most native spring wildflowers. They are extremely difficult to Control: same as for Phragmites eradicate once established – up to or mow several times a season. Control: it is not yet known 10 years of repeated treatment whether digging is effective – the may be needed to remove Purple Japanese Knotweed, Mexican small reproductive corms break off loosestrife or Phragmites. These Bamboo ( Polygonum cuspidatum) very easily. plants propagate by seed and by can grow in shade. The stems have fleshy root parts which break off knotty joints, reminiscent of Try digging (1) before the plants easily. Both are spread by water, bamboo. It grows 6-10 tall and flower. Otherwise, use Rodeo (10 or feet (human, animal, bird), and has large pointed oval or 11), preferably in February to tires, including those of mowers. triangular leaves. protect native plants, frogs, and They are also found in dredge spoil, salamanders which become active fill dirt, and compost. it is not Control: cut at least three in March. clear whether seeds may be times each growing season and/or transported by wind. treat with Rodeo (10) or (11). In gardens, heavy mulch or dense Recommended Native Wetland Do not plant exotic water shade may kill it. Plants for Water Gardens garden plants unless they are not hardy, and never dump plants Purple Loosestrife (Lythrum s Turtlehead from fish tanks or water gardens salicaria, L. virgatum), a (Chelone glabra) into toilets, storm drains, lakes, handsome garden plant, has tall or streams. spikes of magenta flowers over a s Lizard’s tail long bloom season. (Saururus cernuus) Common Reed (Phragmites australis,formerly P. communis) Often marketed as sterile, it is s Cardinal flower looks like a tall ornamental grass at best self-sterile, i.e., it can be (Lobelia cardinalis) with lovely plumes, usually white or pollinated by plants you may not tan. be aware of, growing nearby. s New York ironweed (Vernonia noveboracencis) Although the species is A single plant can produce up to indigenous, a particularly a million seeds. Like Phragmites, it s Blue flag (Iris versicolor) aggressive strain, probably chokes out all competitors and introduced or a hybrid, has has taken over millions of acres of s Virginia bluebells escaped from natural controls and wetland in the U.S. (Mertensia virginica) taken over many formerly diverse wetlands. It is also seen in Control: initial infestations may s Wild blue phlox roadside ditches. be hand-pulled (1) before flowering (Phlox divaricata) (do not dig). Bag and burn or send Control: (10) or (11), using Rodeo to the landfill. Otherwise, use s Arrowhead when the plant is flowering. If Rodeo (10) or (11) when plants (Sagittaria latifolia) possible, follow-up with a begin to bloom (they continue to controlled burn of the dead plants, flower while setting seed). Expect s Pickerelweed to allow native plants to return. to re-treat for several years until (Pontederia cordata) the seed bank is exhausted. Do not dig Phragmites – the s Also use native reeds, rushes, roots will break, re-sprout, and Lesser Celandine, Celandine and sedges. spread. If herbicide cannot be Buttercup ( Ranunculus ficaria)© WindStar Wildlife Institute Page 4 A Plants Home
  5. 5. Small to Medium Invasive, Flowering Fruit Trees – these Non-Native Trees displace our native fruit trees: Recommended Small Native Empress Tree, Princess Tree Cherry, edible and ornamental Ornamental Trees (Paulownia tomentosa) – large (Prunus avium, P. cerasus , Serviceberry ( Amelanchier spp.), panicles of lavender flowers, like Japanese species and hybrids). Fringetree ( Chionanthus upside-down wisteria, identify this Pear, Bradford and other virginicus ), Black haw (Viburnum tree in spring; the large brown Ornamental Pears ( Pyrus prunifolium), and Red seed capsules remain all year. calleryana ) – self-sterile but can chokeberry ( Aronia arbutifolia) pollinate other cultivars, now are beautiful flowering trees Winged seeds allow it to spread spreading rapidly from street that also produce fruit for deep into undeveloped areas, plantings. birds. though it needs some sunlight and is most common along trails and White Mulberry (Morus alba ) – waterways. It grows very rapidly the fruits may be white, purple, or and sprouts readily from roots black; leaves are lobed. Our under which nothing else grows. Its and cut stumps. delicious native red mulberry, which small oval leaves have a single has very large, usually unlobed tooth. Control: (1) – seedlings and leaves, is dying out from a root small saplings only; (7), (8), (9), disease carried by white mulberry. Control: (1); (7), (8), (9), or (10). or (10) – use 50% solution, any time the ground is not frozen; (11) Control of flowering/fruit trees: Russian Olive, Autumn Olive on re-growth and small trees. (1); (7) or (10); (8) if very large; or ( Eleagnus angustifolium, E. if grown for harvest, protect fruit umbellata ) – formerly Mimosa ( Albizia julibrissin) has from birds with netting or recommended for erosion control rather garish pink flowers in hardware cloth. and wildlife value, these have summer and feathery compound proved highly invasive and diminish leaves. It spreads slowly by wind- Siberian Elm ( Ulmus pumila ), a the overall quality of wildlife borne seed pods, or in water or fill- fast-growing medium-height tree habitat. dirt. It re-sprouts when cut or also sold for hedges, displaces our burned. Needs some sunlight. native elms, which are already Control: (1) – up to 4" diameter under pressure from Dutch elm trunks; (7) or (10) or bury stump. Control: (1); (7), (8), (9), or (10). disease. It forms dense thickets Do not mow or burn. Recommended Native Trees For Hedges Invasive Ornamental Grasses American hazel nut (Corylus americana) makes an excellent hedge. Often promoted as native In damp soils, Slippery elm (Ulmus rubra) is a good substitute for plants, most ornamental grasses Siberian elm. come from outside our region. Once established, they are On sunny, dry sites, Staghorn sumac or Shining sumac (Rhus extremely tenacious. They are now typhina, R. copallina) form thickets; keep suckers in check by mowing. spreading into our meadows. So far, Pampas grass Recommended Native Shade Trees ( Cortaderia selloana and C. White oak (Quercus alba), Northern or Southern red oak (Q. rubra, jubata), Japanese silver grass Q. Falcata), and Mockernut hickory ( Carya tomentosa) are widely ( Miscanthus sinensis ), and Reed adapted shade trees. canary grass (Phalaris arundinacea) have been the most Other oaks and hickories are suited to very dry, wet, or steep sites. invasive. Tupelo, also called Black or Sour gum ( Nyssa sylvatic) has brilliant red fall foliage and small fruits eaten by birds. Control: (1); (2); or (11), using additional sticker-spreader.© WindStar Wildlife Institute Page 5 A Plants Home
  6. 6. Medium to Tall or March to protect surrounding Recommended Native Grasses Invasive, Non-Native Trees plants). Use maximum strength Native grasses usually grow in Norway Maple (Acer specified on label for all herbicide small clumps, in a mix of several platanoides) has large leaves applications on Ailanthus. species. similar to sugar maple. Break a leaf or stalk – a drop of white Glyphosate is not effective Tall ones include Indian grass sap will show if it is Norway against Ailanthus. (Sorghastrum nutans ), Big maple. bluestem ( Andropogon gerardii), Sawtooth Oak ( Quercus Purple top ( Triodi flava), and, on Fall foliage is yellow. acutissima ) – often recommended the coastal plain, Switch grass (Exceptions: cultivars such as for wildlife, this Asian tree has (Panicum virgatum). “Crimson King," which have red spread into our region from leaves in spring or summer, may forestry plants, displacing Small to medium grasses have red autumn leaves.) The indigenous forest trees. include Little bluestem leaves turn color late, usually in (Schizachyrium scoparium), November. Control: (1); (7), (8), (9), or (10); Bottlebrush ( Hystrix patula), (11) on small trees and re-growth. and Wild oats ( Uniola latifolia). This tree suppresses growth of grass, garden plants, and forest understory beneath it, at least as far as the drip-line. This Guide was compiled for the Maryland Native Plant Society by Our mixed deciduous forests Louisa Thompson, Master Gardener Consultant, Maryland Cooperative will give way to pure stands of Extension, March, 1999. Norway maple in the next century unless we control its Sources include: spread now. s “Exotic Plants," by Gene Cooley, MD Natural Heritage Program Control: (1); (7), (8), (9), or (10); (11) in mid-October to early s “Invasive Alien Plant Species of Virginia," by the Virginia Native November, before the leaves turn Plant Society and the VA Division of Natural Heritage color. s “Plant Invaders of Parks and Natural Areas," by the NPCI Alien Tree of Heaven ( ilanthus A Plant Working Group altissima ), known from A Tree Grows in Brooklyn incredibly , is “Invasive Exotic Pest Plants in Tennessee," by the Tennessee Exotic s tough and can grow in the Pest Plant Council poorest conditions. s “Element Stewardship Abstracts" of The Nature Conservancy It produces huge quantities of wind-borne seeds, grows rapidly, s “Invasive Plants: Weeds of the Global Garden," by John M. Randall and secretes a toxin that kills and Janet Marinelli, 1996, Brooklyn Botanic Gardens Book Club other plants. Once established, this tree cannot be removed by s The Monsanto web-page ( www .monsanto .com). mechanical means alone. The author would like to thank Rod Simmons, Jil Swearingen, Susan Control: (1) – seedlings only. Rudy, Susan Salmons, Philip Pannill, Marc Imlay, Marion deGroff, Jane Herbicide – use Garlon 3a(9) Baldwin, Graham Egerton, and Ray Bosmans for their comments. with no more than a 1" gap between cuts, or (10); plus (11) on Control of invasive exotic plants is a new endeavor; the re-growth. Or paint bottom 12" of recommendations given here may not have been fully tested. bark with Garlon 4 (in February© WindStar Wildlife Institute Page 6 A Plants Home
  7. 7. Invasive, Non-Native Vines bright orange seed capsules in Control: clip off flowers or fruits All of these vines shade out the clusters all along the stem, while if any are seen (2), and (1) pull shrubs and young trees of the the native species bears them only any seedlings. To eradicate ivy forest understory, eventually killing at the branch tips. climbing trees, cut stems as high them, and changing the open above ground as you can reach, structure of the forest into a Control: (2); keep ornamental then pull down and paint lower dense tangle. Do not plant next to plants cut back, remove all fruits portion of stems and foliage with open space. as soon as they open, and bag or Garlon 3a (10), taking care not to burn fruits; to eradicate use wet the tree bark. Ground cover: Kudzu (Pueraria lobata), the vine Garlon 3a (10). pull up as much as you can, dig that smothered the South, is now out the roots as well as you can, spreading through the Northeast Porcelain Berry (Ampelopsis and repeat until it no longer re- and Midwest. It grows extremely brevipedunculata) has small, hard sprouts; or treat re-growth with rapidly both above and below fruits in a loose, flat cluster that Garlon 3a. ground, and can pull down trees. turn from white to yellow, lilac, green, and finally a beautiful Wintercreeper ( Euonymus Control: small patches may be turquoise blue. fortunei). Control: same as for eliminated by repeated weeding (1), English Ivy, but Garlon is not mowing (2), or grazing; established Control: (1) before fruits appear; effective; glyphosate mixed with infestations can only be controlled keep ornamental plants cut back, extra sticker-spreader may be. with herbicide (10) or (11) – expect and bag or burn fruits before they re-growth, but wait a full year and ripen; to eradicate use Garlon 3a Vinca, Periwinkle ( Vinca minor). re-treat in the third year. Herbicide (10). Control: with persistence, you can is most effective in early fall. dig out vinca (1); plan to remove Controlled burning (4) of the dead English Ivy (Hedera helix) grows re-growth. If digging is not plants the following spring allows up trees and can eventually pull feasible, cut to the ground and native vegetation to return. them down. It spreads along the treat re-growth with glyphosate ground and occasionally by fruits. (11). Japanese Honeysuckle ( Lonicera japonica), including Hall’s honeysuckle is a rampant grower that spirals around trees, often Recommended Native Ornamental Vines strangling them. American bittersweet (Celastrus scandens) has been almost Control: (1); (3); (10); (11) in fall completely displaced by the Asian species. To preserve it, give it or early spring when native preference, except where its exotic counterpart is present, because vegetation is dormant. Plan to re- the two hybridize. treat repeatedly. Trumpet honeysuckle ( Lonicera sempervirens a semi-evergreen ), Wisteria, Chinese and Japanese twining shrub with tubular red flowers attractive to hummingbirds, is (Wisteria sinensis, W. Floribunda) uncommon but indigenous to the piedmont. both become heavy, woody vines that can pull down a large tree. Native wisteria ( Wisteria frutescens ), much less aggressive than the introduced ones, can be grown from Maryland south. Control: (1); cut back and deadhead ornamental plants (2); Trumpet vine ( Campsis radicans ) has dramatic flowers attractive to (10). hummingbirds, and Virginia creeper ( Parthenocissus quinquefolia has) spectacular red fall foliage, but be aware that both are aggressive Oriental Bittersweet ( Celastrus growers. orbiculatus) has almost completely displaced American Native grapes ( Vitis spp. ) provide an enormous amount of food for bittersweet ( C. scandens ). The birds but are aggressive and not ornamental. Asian plant has its flowers and© WindStar Wildlife Institute Page 7 A Plants Home
  8. 8. Invasive Non-Vining Ground Covers Control: (1) (difficult); (2); (6); Note on Herbicides Crown Vetch ( Coronilla varia) (11). The Maryland Native Plant has striking pink flowers. Its bare Society strongly recommends woody stems are unattractive in Indian Strawberry ( Duchesnea non-chemical methods of winter. Often planted along indica). From India, this shade- control wherever feasible. highways, its seeds spread tolerant ground cover spreads by However, for large infestations, invasively. fruit and runners. and for a few plants, non- chemical methods are Control: (1); (10) or (11). Control: (1), taking care to inadequate. remove each crown; (6). Mints, including Spearmint Applied carefully to avoid non- (Mentha spicata), Ground Ivy, Gill- Running Bamboos (many species target plants, glyphosate is the Over-the-Ground, Creeping Charlie and genera; Phyllostachys, least environmentally damaging (Glechoma hederacea), Henbit Bambusa, and Pseudosasaare the herbicide in most cases. (Lamium amplexicaule), and Purple most destructive). Many bamboos Dead Nettle ( L. purpureum), send runners great distances, Roundup contains a stronger spread by wind-borne seed as well under pavement and edging. concentration of glyphosate as by runners. than Kleen-Up. Both contain a Once established, they form petroleum-based sticker- They grow in sun and shade and impenetrable thickets that are spreader. are common lawn weeds which have almost impossible to eradicate. spread to woods and wetlands. Rodeo, the glyphosate Recognize mints by square stems Plant bamboos only in formulation for wetlands, does and a minty smell when crushed. containers, never in open soil. not contain any sticker- Prevent from spreading out spreader and thus is safer for Plant culinary and ornamental drainage holes. the environment. mints in containers; prevent from spreading out drainage holes or Control: (1) – an enormous job; The smallest size of Rodeo over the top. (10) or (11). available is one quart of concentrate, obtainable from Recommended Native Ground Covers farm supply store for about Evergreen: Golden ragwort (Senecio aureus) and green-and-gold $60. Add food coloring for (Chrysogonum virginianum) have showy yellow flowers in spring and visibility, and a soap-based grow in moist shade. Wild stonecrop (Sedum ternatum) has lacy white sticker such as Cide-Kick. flowers; it grows in thin, rocky soil in light shade. Moss phlox (Phlox subulata), the familiar landscape plant, has a looser form in the wild, For small applications, and usually has white flowers; it tolerates very poor soil but needs another choice is Roundup Sure good drainage. Shot Foam, easier to see and control than liquid Roundup. Semi-evergreen: Allegheny spurge (Pachytsandra procumbens) is indigenous to the mountains but will grow here. It looks much like its Glyphosate is ineffective on Japanese cousin. some plants; for these, triclopyr (Garlon), a stump and Deciduous: Wild ginger (Asarum canadense) has kidney-shaped brush killer, may be indicated or leaves that seem to sparkle in spring. Not a culinary plant, its roots Crossbow, which will not kill do have a gingery scent. it needs moist shade. grass. When using herbicides, read Recommended Alternatives to Bamboo the entire label and observe all Giant cane (Arundinaria gigantea), a well-behaved native bamboo, is precautions listed, including indigenous to damp woods and swamps on the coastal plain. proper disposal. If in doubt, call Elsewhere, use native grasses or shrubs. your state Extension Service.© WindStar Wildlife Institute Page 8 A Plants Home
  9. 9. Control Measures (1) Pull seedlings and small or shallow-rooted plants when soil is moist. Dig out larger plants, including the root systems. Use a spading fork or weed wrench for trees or shrubs. (2) To prevent spread of seeds of desirable ornamental plants, cut off spent flowers (“deadhead") or cut off seeds or fruits before they ripen. Bag, and burn or send to the landfill. (3) Mow or cut back at least three times a season to deplete plants’ store of nutrients, reduce seed formation, and kill or minimize spread of plants. If necessary, repeat each year. (4) Controlled burning during the spring, repeated over several years, allows native vegetation to compete more effectively with the exotic. This may require a permit. Spot treatment with glyphosate in the late fall can be used to make this method more effective. (5) Use a corn-based pre-emergence herbicide on annual weeds. This product is also an organic fertilizer, i.e., it can stimulate growth of existing plants, including weeds, so it is appropriate for lawns and gardens but may not be appropriate in woodlands. (6) In lawns, spot treat with broad-leaf weed killer. Good lawn-care practices (test soil – use lime and fertilizer only when soil test shows a need; mow high and frequently – leave clippings on lawn) reduce weed infestations. (7) Cut down the tree. Grind out the stump, or clip off re-growth. (8) Girdle tree – cut through the bark and growing layer (cambium) all around the trunk, about 6" above the ground. Girdling is most effective in spring when the sap is rising, and from middle to late summer when the tree is sending down food to the roots. Clip off re- growth. (9) Hack and squirt – hack a hole (several holes in larger trees) WindStar Wildlife Institute is a downward into the growing layer, and squirt in glyphosate (or national, non-profit, conservation triclopyr if recommended in text above). Follow label directions for organization whose mission is to Injection and Frill Applications. This is most effective from middle to help individuals and families late summer. Clip off any re-growth or paint with glyphosate. establish or improve the wildlife habitat on their properties. (10) Cut down, and paint the cut stem or stump with glyphosate (or triclopyr if specified above). Follow label directions for Cut Stump For more information or Application. Clip off re-growth or paint with glyphosate. (See Note on for the name of a Master Wildlife Herbicides.) Habitat Naturalist in your area, please contact: (11) Paint foliage with glyphosate herbicide (see Note on Herbicides). Use an envelope dauber (small sponge-topped bottle), following label WindStar Wildlife Institute directions for “wiper" method. Add a drop of food color for visibility. Or use a foam spray. Avoid dripping on non-target plants, because glyphosate kills most plants except moss. If it rolls off waxy or grass- E-mail: like foliage, use additional sticker-spreader. Deciduous trees, shrubs, and perennials move nutrients down to the roots in late summer. Glyphosate is particularly effective at this time and when flowering plants are in bloom. Several invasive exotics retain their foliage after native plants have lost theirs, and resume growth earlier in spring Photography by than most natives. This allows you to treat them without harming Catherine Gilleland, Maryland the natives. However, the plant must be growing for the herbicide to Master Wildlife Habitat Naturalist work, and more may be needed in cold weather because growth is slower.© WindStar Wildlife Institute Page 9 A Plants Home