Invasive Buckthorn

Buckthorn before and after

Replace buckthorn with recommended native shrubs and trees.

Buckthorn (Rhamnus cathartica) is an invasive species of shrub or tree, reaching up to 30 ft. high. It forms dense thickets and reproduces freely, crowding our other plants and disrupting ecosystems in forest preserves and other natural areas. Two species are found in Lake County: Common buckthorn and glossy buckthorn. Its oval, shiny leaves have prominent veins and a slightly curving tip, and grow one to four inches long. Pale green-yellow flowers appear July though September. Both species produce quarter-inch, black fruit by September. Birds and other wildlife eat this fruit and disperse the seeds, spreading buckthorn into new areas. By developing a network of critical landscapes, everyone can work together to safeguard the resources and places that benefit people, wildlife and the economy.

Buckthorn is the most common tree in the Chicago region, making up approximately 40% of our canopy, according to a 2010 tree census conducted by the U.S. Forest Service and The Morton Arboretum. It will continue to be an issue until the whole community is involved: from private landowners to homeowner associations, gold courses to garden clubs, businesses to school districts. Under the Illinois Exotic Weed Act, buckthorn cannot be sold in Illinois. But momentum is building and will continue to build. See below for recommended species to plant in place of invasive buckthorn. Together, public and private partners are working towards a buckthorn-free Chicago region. Let's tell this invader: "The BUCKTHORN stops here!"

PHOTOS above: Before & After Buckthorn Removal at Almond Marsh Forest Preserve. 
Credit: Lake County Forest Preserve 

 

Recommended privacy screen replacements, following removal of European buckthorn:

Grass, Ground and Herbaceous

Canada Anemone (Anemone canadensis) 1-2' H x 1' W". Tolerates wet conditions.
Wild Ginger (Asarum canadense) 6" H x 6-12" W. Prefers shade.
Butterfly Weed (Asclepias tuberosa) 2-3' H x 2-4' W: One of the showiest milkweeds, it has orange flower clusters and long. narrow leaves. Drought tolerant and a host for many pollinators. Prefers sunny locations, dry conditions.*
Swamp Milkweed (Asclepias incarnate) 2-5' H x 2-3' W. Prefers sun and wet conditions.
Lady Fern (Athyrium filix-femina) 2' H x 1' W. Prefers shade.*
Hairy Wood Mint (Blephilia hirsutus) 3' H x 18" W. Prefers shade.
Wild Hyacinth (Camassia schilloides) 6-12" H x 12" W. Prefers sun.
Palm Sedge (Carex muskingumensis) 2-3' H x 1-2' W. Tolerates wet conditions.
Curly Wood Sedge (Carex rosea) 12" H x 12" W. Prefers shade.
Beak Grass (Diarrhena obovata) 2' H x 1-2' W. Prefers shade.
Pale Purple Coneflower (Echinacea pallida) 2-3' H x 1-2' W. Prefers sun.
Bottlebrush Grass (Elymus hystrix) 3-4' H x 1" W. Prefers shade.
Purple Lovegrass (Eragrostis spectabilis) 1-2' H x 1-2' W. Prefers sun and dry conditions.
Big Leaf Aster (Eurybia macrophylla 1' H x 1' W. Prefers shade.
Wild Geranium (Geranium maculatum) 1' H x 1' W: Colony-forming forb with showy pink-purple flowers. Prefers shade.*
Rough Blazing Star (Liatris aspera) 2-3' H x 1-2' W. Prefers sun and dry conditions.
Virginia Bluebells (Mertensia virginica) 2' H x 1-2' W. Prefers shade.
Solomon's Seal (Polygonatum biflorum) 2-4' H x 1-2' W. Prefers shade and dry conditions.
Wild Petunia (Ruellia humilis) 1-2' H x 1-3' W. Prefers sun and dry conditions.
Little Bluestem (Schizachyrium scoparium) 2-4' H x 1-2' W. Prefers sun and dry conditions.
Prairie Dropseed (Sporobolus heterolepsis) 1-2' H x 2-3' W: Dense tufts of sprawling narrow-leaved grass that turn golden in fall with a lovely sweet scent. Prefers sun and dry conditions.*
Sky Blue Aster (Symphyotrichum oolentangiense) 2-3' H x 1-2' W. Prefers sun.
Golden Alexanders (Zizia aurea) 1-3' H x 2-3' W. Tolerates full sun to shade.

*Species are our top picks.  

 

Shrubs

Lead Plant (Amorpha canescens) 1-3' H x 1-3' W. Prefers sun and dry conditions. 
Shrub Indigo (Amorpha fruticosa) 10-15' H x 15-20' W. Prefers sun and wet conditions.
New Jersey Tea (Ceanothus americanus) 2-4' H x 2-4' W: Posies of white flowers transform into unique seed heads for winter interest on this densely rounded shrub. Prefers sun.*
Buttonbush (Cephalanthus occidentalis) 6-12' H x 12-18' W. Tolerates wet conditions.
Hazlenut (Corulus Americana) 5-8' H x 12-18' W. Prefers sun.
Witchhazel (Hamamelis virginiana) 10-20' H x 15-20' W. Tolerates dry conditions.
Wild Hydrangea (Hydrangea arborescens) 3-5' H x 3-5' W. Tolerates wet conditions.
Shrubby St.John's Wort (Hypericum prolificum) 2-5' H x 3-5' W. Tolerates dry conditions.
Winterberry (Ilex verticulata) 6-12' H x 6-8' W. Tolerates wet conditions.
Spicebush (Lindera benzoin) 6-12' H x 6-12' W. Tolerates wet conditions.
Ninebark (Physocarpus opulifolius) 5-10' H x 5-10' W. Tolerates dry conditions.
Fragrant Sumac (Rhus aromatic) 5-8' H x 5-10' W. Prefers sun.
American Currant (Ribes americanum) 3-5' H x 3-5' W: Fast growing shrub with arching stems. Drooping yellow flowers mature into sweet-tart, edible fruit. Fall foliage is a lovely red. Tolerates wet conditions.*
Carolina Rose (Rosa Carolina) 3-8' H x 4-6' W. Prefers sun.
Prairie Willow (Salix humilis) 5-8' H x 2-5' W
Elderberry (Sambucus Canadensis) 5-10' H x 5-10' W. Tolerates wet conditions.
Bladdernut (Staphylea trifolia) 10-15' H x 8-12' W
Early Low Blueberry (Vaccinium angustifolium) 2-3' H x 2-4' W: A tough little shrub with white flowers in spring that attracts insects. Fruits appear in June and attract birds when ripe.*
Nannyberry (Viburnum lentago) 15-20' H x 8-10' W: Excellent privacy hedge replacement. Has clusters of white flowers in summer and lovely red foliage in fall.*
Blackhaw (Viburnum prunifolium) 12-15' H x 12-20' W

* Species are our top picks.  

 

Understory/Small Trees

Downy Serviceberry (Amelanchier arborea) 15-25' H x 10-12' W. Tolerated dry conditions.
Allegheny Serviceberry (Amelanchier laevis) 15-25' H x 15-25' W
Blue Beech (Carpinus caroliniana) 20-25' H x 15-25' W: Mid-sized trees with smooth, gray bark. This tree grows well in different soils and pH.*
Redbud (Cercis canadensis) 20-30' H x 25-35' W: Attractive multi-stemmed tree with heart-shaped leaves. Magenta flowers in spring transform into unique peapods.*
Pagoda Dogwood (Cornus alternifolia) 15-25' H x 20-30' W
Cockspur Hawthorn (Crataegus crus-galli) 20-25' H x 20-25' W
Downy Hawthorn (Crataegus mollis) 20-30' H x 20-40' W: Hardy hawthorn with distinct lateral branching, soft fuzzy leaves and showy white flowers followed by red fruits.*
Ironwood (Ostrya virginiana) 40-45' H x 20-30' W
Chokecherry (Prunus virginiana) 20-25' H x 15-20' W
Staghorn Sumac (Rhus typhina) 15-25' H x 15-25' W
Arborvitae (Thuja occidentalis) 30-60' H x 10-15' W: This is a hardy, versatile evergreen. The narrow profile makes it a nice choice for windbreaks. It requires very little care when used as a hedge.*
American Beech (Fagus grandifolia) 50-80' H x 50-70' W
White Pine (Pinus strobus) 80-120' H x 20-40' W
White Oak (Quercus alba) 60-100' H x 100' W: Stately long-lived oak found in every county of Illinois. Features light gray bark and rounded leaves that turn a rich red in fall.*
Red Oak (Quercus rubra) 60-100' H x 100' W
Basswood/Linden (Tilia Americana) 60-90' H x 30-60' W
Canadian Hemlock (Tsuga Canadensis) 40-70' H x 24-35' W*

Species are our top picks.  

 

Tips from our landscape Architects & Best Practices

- Identify invasive species and remove them. Buckthorn is best controlled by cutting the stem a few inches above the soil, then applying herbicide to the cut stump.

- Assess what you have. Bare spots? Trees? Low areas with water? Have your soil tested. Learn the right plants for the right yard.

- Consider planting native species.

- Reduce turf grass and pesticide use.

- Eliminate insecticide use.

- Conserve water and collect rainwater.

- Use a mulching mower instead of a bagger. Alternatively, rake and compost leaves and clippings to redistribute on gardens for nature's free fertilizer.

-- Learn more online at chicagorti.org/HealthyHedges