Description

Common Buckthorn is a deciduousa shrub or tree which sheds its leaves annually small tree or coarse shrub. It grows 6.5-20 feet tall. The glabroussmooth; free from hairs branches usually have shoots that are tipped with stout spines. The leaves are opposite to subopposite, elliptic to ovate, 1.5-3.0 inches long and can be acute or obtuse. They are glabrous and have minutely serrate margins. The lateral veins (usually 3, but can be 2 or 4) on each side are strongly upcurved. The leaves remain on the plant late into the autumn, when most of the native species have already lost their leaves. The fragrant, non-showy yellow-green flowers of Rhamnus cathartica are polygamodioecioushaving bisexual and male flowers on some plants, and bisexual and female flowers on others, 4-petaled, and are present in clusters of 2-6. These flowers appear in the spring while the leaves are expanding, and are borne near the bases of the leaf stalks. The dark, purple to black fruit are globose drupes, about 0.25 inches across, contain 3-4 seeds and appear in the fall.

Habitat

Rhamnus cathartica can be located in open woods, pastures, fence rows, roadsides, moist and dry upland sites, floodplain and riparianthe area immediately adjacent to running freshwater forests and ravines. It grows in well-drained soils, preferring neutral to basic soils. In calcareous soilssoils formed from the crushed up and decayed shells and bones of sea creatures situations, it can form extensive monotypic standsan area dominated by a single species

History and Introduction

Common buckthorn was recommended as a quick-growing hedge plant and shelter belt for crops, common buckthorn was introduced over two hundred years ago and reported as escaped from cultivation by as early as 1800. 

This species was introduced to North America as an ornamental shrub and used for living fence rows and wildlife habitat. Since its introduction, it has spread aggressively across most of the northeast.

Threats

Rhamnus cathartica has the ability to form dense thickets under which native vegetation cannot survive due to shading and crowding. Many types of birds, as well as small mammals, eat its fruit, easily dispersing it over long distances. Rhamnus cathartica is a threat to agriculture because it is an alternative host for the crown rust of oats. This rust has a major effect on the yield and quality of the crop. Rhamnus cathartica plants can regenerate even after they are cut or burned.

Dispersal Methods

The seeds of Common Buckthorn are dispersed by birds.

Control

As with any other invasive infestation complex, large stands of common buckthorn are best managed via a combination of mechanical and chemical means. Small seedlings and plants can be hand pulled or removed using a weed wrench while larger shrubs must be cut and sprayed, either with a basal bark or cut stump application, to attain good control. All managed infestations should be monitored to ensure exhaustion of the seed bank for at least two years and to prevent reinvasion from nearby populations. Any new seedlings can be hand pulled or sprayed. 

Mechanical

Remove plants before producing fruit by hand pulling or digging; use control burning in spring and fall, burning may need repeating annually or biannually for two to three years to deplete the seed bank. 

Chemical

It can be effectively controlled using any of several readily available general use herbicides such as glyphosatea widely used herbicide that can kill certain weeds and grasses, it works by blocking an enzyme essential for plant growth or triclopyrherbicide used to control both broadleaf and woody plants. Retreat foliage of re-sprouts. Follow label and state requirements.