Common buckthorn is an invasive plant in Illinois and should not be planted. It forms dense thickets and reproduces very freely, crowding out other plants and disrupting ecosystems in forest preserves and other natural areas. In woodlands it can completely replace existing understory plants; including native wildflowers. Buckthorn has berries that are spread by birds. The seeds germinate at a very high rate and remain viable in soil for two to three years. Buckthorn is very common in gardens and yards in the Midwest, but should be removed where it is found. Buckthorn is a large shrub or tall tree with glossy oval leaves that can easily be recognized in fall, when it remains green after most other leaves have fallen.
- Deciduous (seasonally loses leaves)
- Zone 3
- Zone 4
- Zone 5
- Zone 6
- Zone 7
- Full sun (6 hrs direct light daily)
- Partial sun (4-6 hrs light daily)
- Full shade (4 hrs or less of light daily)
- Dry sites
- Wet sites
- Road salt
- Acid soil
- Alkaline soil
- Dry soil
- Moist, well-drained soil
- Wet soil
- Small tree (15-25 feet)
- Large shrub (more than 8 feet)
- Late spring
Tree & Plant Care
This is an invasive plant. Do not plant it.
However, if the plant is already persisting, there are several management methods. The buckthorn can be managed culturally by pulling small plants and seedlings or mowing them over. Large plants can be girdled by removing 2 inch strips of bark from each stem and applying herbicide to the girdled surface. The buckthorn can also be controlled chemically in late fall. Systemic chemicals can be sprayed and drawn down into the plant’s roots. Furthermore, a stump treatment can be implemented by using glypsophate or triclopyr paint or spray on a freshly cut stump.
Disease, pests, and problems
Buckthorn is susceptible to rust and powdery mildew.
Buckthorn is on Illinois’ exotic weed list due to its high germination rate in a variety of habitats including gardens, fence rows, pastures, prairies, and abandoned farm fields. In woodlands it can completely replace existing understory plants; including native wildflowers. Seeds remain viable in soil for 2-3 years which contributes to the invasive nature of this plant.
Native geographic location and habitat
Attracts birds, pollinators, or wildlife
Birds love the plant’s berries and disperse them everywhere.
Bark color and texture
The tree’s bark is brown to gray in youth, rough and peeling with prominent whitish lenticels and yellow coloration on the inside. The bark may form dense thickets.
Leaf or needle arrangement, size, shape, and texture
- Arrangement: opposite to sub-opposite leaf arrangement
- Size: 1 ½ -3” long and ¾ - 1 ½” wide
- Shape: single, elliptical
- Texture: medium to coarse, minute teeth on margins, rounded to point tips
- Remain bright green in fall for some weeks after most other shrubs and trees have lost their leaves
Flower arrangement, shape, and size
- Shape: 4 petals in leaf axils
- Size: small, dioecious
Fruit, cone, nut, and seed descriptions
- Type: berry-like, clustered, on female plants only
- Size: pea-sized
- Color: dark blue in late spring and early summer, turn black in August and persist throughout the winter