Students for Stewardship The Cork Board
← Back to the library

Common Buckthorn

Rhamnus cathartica (RAM-nus kat-AR-tik-uh)

Family: Rhamnaceae Non-native Understory (15-40 ft)

Common buckthorn is a deciduous shrub or small tree in the Rhamnaceae or buckthorn family and is native to Europe, Africa and northern Asia. It was introduced to North America in the early 1800s and has spread and become invasive in many northeastern states and Canada. It is found in disturbed areas such as roadsides, fencerows, fields, and pastures and undisturbed areas such as riparian, wetland edges and ravine slopes. The plant grows moderately fast, tolerates shade and is short-lived. The species name cathartica refers to its purging effects. The tree will grow to 30 feet tall with thorny crocked branches. Due to hybridization with native buckthorns, the plant can be variable in looks The leaves can be opposite, to sub-opposite or even alternate on the stem. The flowers are either male or female and inconspicuous in spring. There are separate male and female trees. Small round drupes appear after blooming on the female trees. It is mildly toxic to humans and mammals but birds will eat the fruits and disperse the seeds. The tree will grow in full sun to shade and tolerates moist to well-drained soils. It is difficult to eradicate as it sprouts readily from stumps. Treating stumps has some benefits but the seeds stay viable for years and can sprout at any time. Common buckthorn provides dense shade that can interfere with the establishment of native plants and alters the ecosystem. Please see native alternatives to the left. Insects, Diseases, and Other Plant Problems: Invasive in many northeastern and midwestern states. More information on Rhamnus .

Source: NC State Extension Gardener Plant Toolbox ↗ NC State Extension Gardener Plant Toolbox, 66 attributes.

How it fits the guild

Guild layer 2 - Understory (15-40 ft) Optimal soil pH Alkaline (>8.0); Neutral (6.0-8.0)
See companions & conflicts ↓

Companions & Conflicts

Curated pairwise relationships between this plant and others in the library — who feeds whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.

No curated interactions recorded for this species yet.

Also noted by NC State

Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.

Often confused with Frangula alnus Frangula caroliniana
Fills a similar niche Ampelopsis glandulosa var. brevipedunculata Elaeagnus umbellata Lonicera japonica

Full plant profile

Growing Conditions
Plant type
Poisonous; Tree
Life cycle
Woody
USDA zones
3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b
Light
Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
Clay; Loam (Silt); Sand
Soil pH
Alkaline (>8.0); Neutral (6.0-8.0)
Soil drainage
Good Drainage | Moist | Occasionally Dry | Occasionally Wet
NC region
Mountains; Piedmont
Mature size
Height: 18 ft. 0 in. - 30 ft. 0 in. | Width: 15 ft. 0 in. - 20 ft. 0 in.
Growth rate
Rapid
Maintenance
High
Canopy layer
2 - Understory (15-40 ft)
Form & Appearance
Habit / form
Erect; Multi-stemmed; Multi-trunked; Rounded
Texture
Medium
Foliage
Deciduous
Leaf color
Green
Leaf type
Simple
Leaf arrangement
Alternate; Opposite
Leaf shape
Elliptical
Leaf margin
Dentate
Leaf feel
Smooth
Leaf size
1-3 inches long, 1-3 inches wide
Hairs present
No
Leaf detail
The simple leaves are sub-opposite, opposite or nearly alternate, elliptical in shape with toothed margins, arching leaf veins, and a rounded or small pointed tip, rounded or tapered base on a hairy stalk. 1-3" long by 1- 1.5" wide. Leaves persist into late fall.
Fall color
Gold/Yellow
Flower color
Gold/Yellow; Green
Flower form
Insignificant
Flower size
< 1 inch
Flower detail
Separate male and female flowers. Flowers are yellowish green in clusters, less than ¼ inch across with 4 prominently spreading sepals. Male flowers with four erect greenish stamens and the female with a single style, the tip 4-parted
Bloom time
Spring
Fruit color
Black
Fruit type
Drupe
Fruit size
< 1 inch long, < 1 inch wide
Fruit detail
Fleshy round drupe, 1/4 to 1/2 inch wide. Glossy black with 2-4 seeds mature in fall
Bark color
Dark Brown; Dark Gray; Orange
Bark detail
The bark is dark brown to dark gray, peels with age and is dotted with vertical light-colored lenticels. The inner bark is orange.
Stem color
Brown/Copper; Green
Stem detail
Crocked green to green-brown mature to brown. At the tip there is often a straight thorn with two elongated, brown scaly buds on opposite sides that curve in similar to a deer hoof, hence the common name
Wildlife & Ecology
Native status
Non-native
Origin
Europe to Western Siberia and North West China and NW. Africa
Wildlife value
Fruit attracts birds
Attracts
Songbirds
Food & Medicine
Harvest time
Fall
Fruit type
Drupe
Landscape Use
Garden tags
#deciduous #poisonous #thorns #purple #shrub #multitrunked #high maintenance #fast growing #aggressive #bird friendly #tree #weedy
Problems & Resistance
Problems
Spines/Thorns; Weedy
Resistant to
Drought
Poison severity
Low
Poison parts
Fruits
Poison symptoms
Nausea, vomiting, and diarrhea.
Toxic principle
Glycosides.
Contact dermatitis
No
Toxicity summary
Low severity poison; parts: Fruits

Planted at Hunnicutt

Nobody’s planted this one yet.