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HomeMy WebLinkAboutItem XI - Controlling Buckthorn A L 17 TLE HISTORY BUCKT14ORN . Common,or European buckthorn, and glossy buckthorn are the two non What You Should Know. What You Can Do. native, invasive buckthorn species found in Minnesota. Common buckthorn was first brought here from Europe in the mid-1800s as a popular hedging material. It escaped and became a nuisance plant, farming dense thickets in forests,yards, parks, and roadsides. It crowded out native plants and displaced the native shrubs and small trees in the mid-layer of the forest where many species of birds nested,Today, common buckthorn is found in nearly every Minnesota county,even o though the sale,transport, z and movement of these plants is prohibited. c „ �.. Glossy buckthorn,also from Buckthorn leafs out early and retains its leaves late into the fall,creating dense shade that helps Europe, has been sold by it to out-compete many native plants. the nursery trade in three different forms.The cultivar What happens when buckthorn has been planted as an Frangula alnus 'Columnaris'is ornamental shrub,hedgerow,shelterbelt,or tree in your narrow and tall;the cultivars backyard? Frangula alnus 'Asplenifolia' and 'Ron Williams'have An impenetrable, messy thicket grows that: narrow leaves that give them Out-competes native plants for nutrients, light,and a fern-like texture. moisture. • Degrades wildlife habitat. •Threatens the future of forests,wetlands, prairies,and other natural habitats. •Contributes to erosion b oat-competing etin plants on the y p g P forest floor that help hold soil in place. Serves as host to other pests,such as crown rust fungus and soybean aphid. • Creates messy fruits that stain sidewalks and driveways. • Lacks natural controls,"such as insects or disease that would curb its growth. iii� elf „ �a Glossy buckthorn Deborah Rose,MN DNR Ninneso#n NINE •• • • • « . « « « —• •- prranr�ewr COMMON BUCKTHORN GLOSSY BUCKTHORN Scientific Marne Rhamnus cathartica Scientific Name Frangula alnus Other Common European Buckthorn Other Common Fen Buckthorn, Name Name Alder Buckthorn Nursery Bone Nursery `Columnaris' (tall hedge buckthorn) Cultivars Cultivars 4splenifolia' (fernleaf buckthorn) `Ron Williams' (Fine Line°buckthorn) Shape of 10-25 feet tall; oval form; upright; Shape of 10-18 feet tall;oval form; upright Plant frequently multi-stem Plant Habitat Dry to moist areas such as woodlands, Habitat Primarily wet areas(bogs, marshes, savannas,abandoned fields,roadsides. riverbanks,wetlands, pond edges), but It will grow in both full sun and in shade. also will grow in dry areas. It will grow in both full sun and in shade. Leaves Egg-shaped,dark green,dull to glossy; Leaves Oval,smooth,dark green,glossy,with with finely tooth edges;3-5 toothless edges;8-9 pair pair of curved leaf veins. '' of leaf veins. Leaves get Leaves stay dark green �t fall color. Easily confused and on the tree late into o ����� ��! with native chokecherry. fall. Easily confused with ' f r/ dogwoods,plums,and % i z hl' cherries. J , Flowers Small,yellow-green color;4 petals; Flowers Small,creamy-green color;5 petals; z produced in May. Z produced in late May-June. z z � E a 1? Stems Buds are most'commonly sub-opposite, Stems Buds are alternate,fuzzy and brown, but can be opposite or alternate;short, and lack scales; no spine at tip of the '/8'/4-inch sharp spine at tip of the twig. twig. Fruit and Round, berry-like fruit arranged in Fruit and Round,berry-like fruit;'/4 inch diam- Seed clusters;'/4 inch diameter;green Seed eter;produces less fruit than com- (unripe)to black(ripe)color. Each mon buckthorn;red-brown(unripe)to fruit has 3-4 seeds. Berries persist black(ripe)color. Each fruit has 2-3 throughout mid-winter. seeds. Berries do not persist. bud at lip spine at tip m / 7S alternate buds subopposite buds ti CD Fernleafbuckthorn - leaf o alternate buds U alternate leaves W14AT YOU CAN DO TO CONTROL BUCKTHORN Controlling ar Buckthorn Plants Buckthorn plants that are stumps are easily covered and 2 inches in diameter or lost under cut brush and leaves. rir larger are best controlled by cutting the stem at For basal bark treatment,a z --' the soil surface and then method that applies chemical treating e custump tprevent through the bark, low-volume p with herbicide to spray applications can be made re sprouting.This can be z , with Garlon 4, Pathfinder II, done effectively with hand' and similar oil-based products. tools, chain saws, or brush cutters. i This application method uses IN Stumps should be treated within -;L triclopyr ester mixed with an two hours after cutting.Treat oil diluent (e.g., Bark Oil Blue, 1 with an herbicide containing kerosene, or diesel oil)applied directly to the bark of glyphosate (Roundup, Podeo, etc.) uncut buckthorn from the root collar up about 12-18 inches. 0 or triclopyr(many brush killers, This treatment works best on stems less than 5 inches in -' Garlon 3A, Garlon 4, etc.)to diameter. An ultra low-volume spray wand should be used prevent re-sprouting. Herbicides to minimize herbicide use and reduce the potential for can be applied to cut stumps with non-target injury. Buckthorn treated in this fashion can be 6 a paintbrush,wick applicator, left standing or cut at a later date after the plant dies. dauber, or a low-volume sprayer. Apply the herbicide to the outermost growth rings When applying chemical treatments in the fall and next to the bark(see photo).The best time to cut and winter,follow herbicide label instructions regarding chemically treat the stumps is in late summer(avoid May temperatures at which the herbicide can be applied. and June)and throughout the fall. Water-soluble herbicides like glyphosate(Roundup, Rodeo, etc.)or triclopyr amine (Garlon 3A, brush killers, In cases where more than a few plants are treated, add etc.)can be applied to cut stumps when the temperature an indicator dye (available where pesticides are sold)to is above freezing(32° F).Oil-based products of triclopyr the herbicide to mark the cut stumps you have treated. ester(Garlon 4, Pathfinder II)can be applied when the Colored flags can help mark cut stumps because the temperature is below freezing(below 32° F). Controlling Seedlings and,Small Buckthorn Plants If individual plants are If you wish to hand pull plants less than 3/8-inch ingreater than 3/8-inch, use a diameter, remove them t ;ihand tool that pulls the shrub by hand. Small seedlingsr' out,such as a Weed Wrench or can be pulled and will , ,� �� Root Talon. Hand-pulling tools r`ot re-sprout. If pulling � � o cause soil disturbance so tamp individual plants is °r a� loose soil back into the ground. zimpractical,spray foliage Take extra care when pulling on of short buckthorn or ti � sensitive sites or steep slopes. seedlings with herbicide. Glyphosate will kill all activelyry Pemoving buckthorn by hand is growing vegetation on which it is sprayed.Triclopyr will m ,: easier if the soil is moist. kill broadleaf plants and conifers, but not grasses when applied properly,Spray after native plants have gone Before you pull or dig buckthorn, contact Gopher State dormant(about mid-October). Follow all herbicide label One Call at 651-454-0002 or 8o0-252-1166 to make sure instructions.Applications exceeding maximum labeled there are no buried utilities in the area. amounts may result in a non-target injury. SEED VIABILITY AND THE NEED FOR FOLLOW-UP Buckthorn seeds can remain viable in the soil for up to five years. Follow-up control of seedlings that emerge after initial control efforts is important on all sites.With no follow-up control, buckthorn will come back. Fire offers a long-term management option in grassland or savanna gover-types. Burning will need to be done every two to three years. If burning is not an option,a follow-up treatment of pulling or spraying the seedlings is needed.Successfully treating buckthorn requires a long-term commitment. it i, LIFE AFTER BUCKTHORN Chokecherry (Prunus virginiana) REMOVALChokecherry grows in a variety of Managing your woodland is an ongoing process. Removing soil types. It develops into a tall f buckthorn not only will benefit the environment, it shrub on rich, loam soils, When provides opportunities to create wildlife habitat, redesign planted on dry, sandy soil, it takes your landscape, and beautify an area. Do not make hasty Q on a shorter, bushier form.The decisions with your land after you have removed or bright berries make a delicious controlled buckthorn.Think about the goals and objectives jelly and are an important foal for you have for your property. � wildlife. Short-term recommendations include: • Follow-up buckthorn control in areas where you have Pagoda dogwood (Cornus alternifolia) previously removed buckthorn. Native to rich,deciduous Remove any fruit-bearing buckthorn trees. ill forests, pagoda dogwood • Monitor areas that are relatively buckthorn-free and is also commonly planted control buckthorn plants right away if detected. as a small ornamental tree. �.ong-ter taco en atl 5 Incl It prefers rich, loam soil ® e where the rooting area is • Replant desirable tree,shrub, and herbaceous species ze if species do not return from the seed bank. If you protected from summer are replanting in the same places buckthorn once heat or drought. Its branches spread in horizontal layers, grew,the soil may benefit if you wait one or two giving the tree a beautiful form. years before replanting other trees and shrubs. You American hazelnut (Corylus americana) will also need this time to do follow-up buckthorn American hazelnut is a control. Check with a local nursery, extension service, widespread shrub found Minnesota Department of Natural Resources,or in dry to moist forests and Minnesota Department of Agriculture for assistance z woodlands. It grows in a on species recommended for your area. variety of soil types and • If you are managing a large area, consider fire as part E / tolerates dr sand soil or of a forest management plan. � y' y gravelly slopes. In the open, it sends up many stems, forming clumps. It provides Alternative plantings for buckthorn food and cover for wildlife. Several species of native trees and shrubs display characteristics similar to buckthorn.The following plants Black chokeberry(Aronia melanocarpa) are examples of some of the environmentally-friendly Black chokeberry typically species available at garden centers and nurseries. ° grows at the margins of lakes and wetlands—places where the High—bush Cranberry (Viburnum trilobum) soil is fairly rich and moist,and This multi-stemmed bush where it can get partial sun. It has lovely spring flowers o is colonial, but not aggressive. and persistent red berries. Black chokeberry has attractive Z � Left unpruned, it will grow white flowers in early summer and tall, but it can be pruned r shiny black berries with lovely red into a dense hedge.The foliage in the autumn. European species (Viburnum opulus)is often sold in nurseries but is invasive and should be avoided. FOR MORE INFORMATION: Call the Minnesota Department of Natural Resources Nannyberry (Viburnum lentago) at 651-296-6157 or 888-MINN-DNR � ! gal Nannyberry is a tall shrub or visit www.mndnr.gov/invasives that grows in a variety of Z soils. It spreads gradually ©2013 State of Minnesota, Z from a central clump, Department of Natural Resources forming nicely shaped thickets. It has sweet, STOP INVASIVE SPECIES 4�6/° edible, blue-black fruits. EwR-136,3 IN YOUR TRACKS. Clean' carry.. _..