It’s November in the Midwest and the colorful autumn leaves have fallen. Yet the understory remains a dark green tangle. You’re looking at invasive buckthorn.

Common buckthorn (Rhamnus cathartica) berries and leaves in late fall. — **Invasive buckthorn**

Common buckthorn (Rhamnus cathartica) and glossy buckthorn (Frangula alnus) are invasive woody species in North America. These species were introduced for hedging, but escaped cultivation and have become especially prevalent in Upper Midwestern states like Minnesota, Wisconsin, and Michigan. They form dense, shady thickets, often with sharp thorns that make them impassable. Invasive buckthorns are also allelopathic, meaning they release chemicals into soil to prevent other plants from competing. With no native predators, buckthorn can overwhelm understories, wooded wetlands, and fields. The result can be a complete die-off of native species.

Managing buckthorn is a multi-year process with many techniques for removal. In this post, I’m focusing on revegetation after buckthorn removal. Recent research, especially the Cover it Up! project from the University of Minnesota, has shown that specific native plant species are well-suited for suppressing buckthorn regrowth. These species can outcompete buckthorn in spring and fall, helping revegetate open areas with bare soil. Complementary native plants can also benefit revegetation when planted alongside early establishment species. Check out these native plants for replacing buckthorn!

*Denotes recommendation by Cover it Up! management guide for revegetation.

Trees

Balsam fir (Abies balsamea)*

Balsam fir is common in Minnesota’s northern forests and found scattered further south on cold, wet slopes. Of Minnesota’s native evergreens, balsam fir is best suited for replacing buckthorn. It is shade-tolerant and capable of growing dense understory stands. Balsam fir is a favorite of white-tailed deer, and adding protection around saplings will improve survival.

Ironwood (Ostrya virginiana)

Common in upland deciduous forests, ironwood is a shade-tolerant understory tree. It rarely grows into a canopy tree except around sunny woodland edges, where it can develop a spreading crown. It is an excellent replacement for buckthorn in shady upland woods.

Northern red oak (Quercus rubra)

Northern red oak is not very shade-tolerant, but it is capable of filling canopy openings in mixed forest. Red oak prefers well-drained upland soils, but you can also find it on sandy soils that experience occasional fire, like pin oak savanna. When replacing buckthorn with red oak, you must also include native shrubs or grasses to suppress buckthorn regrowth while slow-growing oak saplings establish.

Sugar maple (Acer saccharum)

Sugar maple is renowned for its sublime fall color, and its sweet spring sap used for maple syrup. It prefers rich, moist soils. Young trees can survive in deep shade until there’s a canopy opening, making sugar maple ideal for planting in mature forests.

Black cherry (Prunus serotina)

Black cherry is a staple of hardwood forests and grows into a large tree. In many visual aspects, black cherry resembles buckthorn, but has thornless bark, edible berries, and striking fall color. Black cherry drops its autumn leaves much earlier than buckthorn, so it must be planted alongside companion shrubs or grasses that can suppress buckthorn regrowth in spring and fall.

Shrubs

Red elderberry (Sambucus racemosa)*

Red elderberry is a large shrub with sizable leaves that appear early in spring and hang on into late autumn. The spring and fall shade from those leaves is exceptional at suppressing buckthorn regrowth, according to the Cover it Up! research. Keep in mind that the red berries aren’t edible, although they look great and attract birds.

Leatherwood (Dirca palustris)

Leatherwood is an underappreciated shrub for full shade. It has attractive yellow flowers and twigs so flexible they can be tied in knots. Leatherwood bark can cause contact dermatitis when handled by some people, so wear gloves when planting.

**Red-twig dogwood (Cornus sericea)**

Growing in wetlands and wet forests, red-twig dogwood competes well against invasive buckthorn. It has attractive red stems, clusters of bird-friendly berries, and spreads readily to fill open spaces, like those left after buckthorn removal.

American hazelnut (Corylus americana)

American hazelnut is often found in oak savanna and upland forest. It is drought-tolerant and features edible nuts prized by squirrels. The fall foliage takes on vivid hues and American hazelnut spreads readily in open woods.

Serviceberry (Amelanchier spp.)

Serviceberry species are considered “keystone species” because they play a critical role in supporting ecosystems. Several species are native to Minnesota, all producing edible berries. Downy serviceberry (Amelanchier arborea) is a flowering tree reaching the western edge of its range across eastern Minnesota. Smooth serviceberry (Amelanchier laevis) is the most common serviceberry found throughout the state, and can grow as an understory shrub or tree. Any native serviceberry is an excellent replacement for invasive buckthorn.

Flowers

Wild bergamot (Monarda fistulosa)*

Also called bee balm, wild bergamot is a pollinator magnet. It is especially valued by the federally endangered rusty-patched bumblebee (Bombus affinis). Bee balm grows aggressively and is effective for suppressing buckthorn regrowth in prairie, open woods, and oak savanna.

White snakeroot (Ageratina altissima)*

White snakeroot is a pioneer flower of open woods and readily regrows in spaces where buckthorn has been removed. It often dominates the groundcover in the first two years after seeding or planting, and then slowly succeeds to longer-lived understory species.

Columbine (Aquilegia canadensis) flowering in a home garden. — Columbine (Aquilegia canadensis)*

Columbine’s hanging red flowers are a herald of spring and a favorite of pollinators. Columbine forms robust colonies around woodland edges that will happily bloom in any light conditions. Drier soils are tolerated.

Tall meadow rue (Thalictrum dasycarpum)*

Tall meadow rue is typical of wet woodlands and grows tall white flower clusters in early summer. It has attractive leafy foliage and grows in sun or shade.

Virginia waterleaf (Hydrophyllum virginianum)*

Virginia waterleaf has green foliage with light spots resembling water droplets. It carpets woodlands in late spring and features clusters of lavender flowers. Virginia waterleaf spreads aggressively by rhizomes, which is great for suppressing buckthorn but tricky in a small garden.

Brown-eyed Susan (Rudbeckia triloba)*

Brown-eyed Susan is a Special Concern species in Minnesota, due to habitat loss from agriculture and urban development. That said, it flourishes in home landscapes and can quickly cover bare soil left after buckthorn removal. Plant in mesic or moist soil with at least part sun.

Early figwort (Scrophularia lanceolata)*

Figworts are underappreciated pollinator powerhouses. Small red flowers brim with nectar and attract numerous bees and butterflies. Early figwort can grow under any light conditions, and is adaptable to most well-drained soils. It is well-suited for oak savanna and woodland restoration.

Big-leaf aster (Eurybia macrophylla)

Big-leaf aster is a fixture of northern forests, often forming large colonies with leafy green foliage. Purple flowers erupt in late summer and look stunning next to goldenrods. Big-leaf aster is adaptable to most soil and light conditions, and will grow on rocky soils.

Solomon’s plume (Maianthemum racemosum)

Solomon’s plume has arching stems with large, green leaves. Cream flowers appear in late spring, followed by patterned berries turning bright red in autumn. Solomon’s plume can form large colonies in dry, shady areas, making it an ideal plant for revegetating pine forests.

Anise hyssop (Agastache foeniculum)

Anise hyssop is a pollinator magnet, drawing dozens of bee species to its long-blooming purple flowers. This species is quick to establish in part to full sun, often producing blooms in its first year of life. Anise hyssop is also optimal for sensory gardens, thanks to the fragrant aroma of its crushed leaves.

Nodding bur-marigold (Bidens cernua)

Nodding bur-marigold, also known as nodding beggarticks, is an annual flower of wetland edges. It forms large, scattered colonies and readily reseeds each year. The pollen-rich flowers are beloved by bumblebees.

Zigzag goldenrod (Solidago flexicaulis) flowering in a woodland meadow. — **Zigzag goldenrod (Solidago flexicaulis)**

Many goldenrod species are native to Minnesota, but zigzag goldenrod is the most shade-tolerant. It grows semi-aggressively and draws many pollinators to its yellow flowers. Use zigzag goldenrod to revegetate moist woodlands.

Ferns

Ostrich fern (Matteuccia struthiopteris)

Of ferns, ostrich fern is prized for its edible early fronds (fiddleheads) and its tendency to form large colonies. Ferns alone will not suppress buckthorn regrowth, but they are a vital component of revegetation, especially in forests. Ostrich fern prefers moist soil and dappled sunlight.

Sensitive fern (Onoclea sensibilis)

Sensitive fern gets its common name from its tendency to wilt at the first frost. It grows equally well in sun or shade and spreads by rhizomes to create colonies. Sensitive fern prefers moist soils rich in organic matter.

Royal fern (Osmunda regalis)

Royal fern is the largest fern in Minnesota, growing up to six feet in height and diameter. It readily spreads in wetland soils and is an excellent replacement for buckthorn in wet woods.

Grasses

Canada wild rye (Elymus canadensis)*

The elymus genus of rye grasses is especially effective at suppressing buckthorn regrowth, according to the Cover it Up! research. These grasses, including Canada wild rye, establish quickly on open soil and form a thatch that smothers buckthorn seedlings. Canada wild rye grows in almost any soil conditions, but prefers part to full sun.

Virginia wild rye (Elymus virginica)*

Virginia wild rye is similar to Canada wild rye, but is more shade-tolerant and prefers moist riparian soils. It performs admirably in shoreline and forest restorations.

Bottlebrush grass (Elymus hystrix)*

Bottlebrush grass is a shade-loving grass species found naturally in floodplain forest. It grows well in a home garden, though the spiky seeds tend to get stuck in socks. Use bottlebrush grass to replace buckthorn in shady areas with medium soil moisture.

Side-oats grama (Bouteloua gracilis)

Side-oats grama always surprises in the driest years, often growing best during drought conditions when competition is low. It is a relatively short grass, topping out at three feet, and has unique hanging seeds along one side of the stem. Side-oats grama is a great groundcover for sunny, dry soils and competes well against buckthorn in prairies and savannas.

Fowl manna grass (Glyceria striata)

Fowl manna grass is a great replacement for buckthorn in wet soils. It tolerates partial shade to full sun and is commonly found along Minnesota’s lakeshores. The common name derives from the high value of the seeds for wild birds.

Sedges

Common wood sedge (Carex blanda)

On their own, sedges often grow too slowly to impede buckthorn regrowth, but they are crucial for ecosystems. Common wood sedge is a good species for revegetation, and forms colonies in any woodland.

Pennsylvania sedge (Carex pensylvanica)

Prized in home landscapes for its flowing, grasslike appearance, Pennsylvania sedge spreads slowly to carpet forest floors. It is a great option for planting in dry, shady spots.

Fox sedge (Carex vulpinoidea)

Fox sedge grows large, elegant bunches when given full sun and moist soil. It is a great sedge for rain gardens and shoreline restorations.

Ready to tackle buckthorn in your landscape? Schedule a consultation for help creating a management plan for replacing buckthorn with native plants!

Native Plants to Replace Buckthorn