Invasive Plant Species Control
Common Buckthorn
(Rhamnus cathartica)
Native Substitutes
- Black chokeberry (Aronia melanocarpa)
- American hornbeam (Carpinus caroliniana ssp. virginiana)
- Pin cherry (Prunus pensylvanica)
- Fireberry hawthorn (Crataegus chrysocarpa)
- Chokecherry (Prunus virginiana)
Description
Appearance: Tall understory shrub or small tree up to 20' high with a spreading loosely branched crown, often multiple stems at the base. Brown bark with elongate silvery corky projections (caution: native plums or cherries have a similar bark). Female and male plants. A cut branch exposes yellow sapwood and orange heartwood. Twigs often end in stout thorns.
Leaves: Alternate, sometimes opposite; broadly elliptic, pointed at the tip, smooth, dark, glossy and small-toothed. Leaves stay green late into fall.
Flower: Inconspicuous flowers appear in May or June, clustered in the axils of leaves.
Fruit: Clusters of black 1/4" fruit ripen on female plants in August and September.
Seeds: Viable for 2-3 years in the soil.
Root: Buckthorn has an extensive fibrous root system.
Ecological Threat
Aggressively invades oak forests, savannas, prairies and riparian woods, completely eliminating native plant diversity in the understory over time. It thrives particularly on well-drained soils. Plants leaf-out early and retain leaves late into the fall creating dense shade. Seeds have laxative effect on birds who disperse them. Introduced to North America as ornamental shrubs. Also used as a cathartic and may have been brought here as part of pharmacopoeia.
Legal Status: This plant is a restricted noxious weed in Minnesota and the importation, sale, and transportation of the plant or its propagating parts is illegal in the state except as provided by Minnesota Statutes, section 18.82.
Control Methods
| Mechanical | Chemical | Biological |
|---|---|---|
| Prescribed fire | Cut-stump treatment with glyphosate or triclopyr | Research in progress |
| Uprooting in small infestations | Basal bark treatment on stems less than 3" |
Sources
Wisconsin Manual of Control Recommendations for Ecologically Invasive Plants, 1997
Minnesota Department of Natural Resources, Restore Your Shore CD, 2001
