Buckthorn management is one of the toughest challenges facing arborists and landscape managers.  Buckthorn is an extremely invasive tree that has been displacing urban forests and wetlands for years.  Unfortunately, there is no quick fix for our buckthorn dilemma.  Buckthorn management is a long-term and often costly endeavor.  Management plans need to be in place on all levels with homeowners, municipalities, arborists and landscape managers working together to slow down the buckthorn invasion.

A Brief History of Buckthorn

Common buckthorn was commonly planted for years as a hedge or windbreak.  The growth form is a multi-stemmed, medium sized tree. Female trees produce large quantities of fruit contributing to the rapid spread of buckthorn.  Glossy buckthorn, or columnar buckthorn, has also been planted for years.  Glossy buckthorn produces fruits continuously for several months, a common trait of invasive plants.  Common buckthorn is generally associated with terrestrial plant communities, while glossy buckthorn is associated with wetland communities.  However, they are readily seen invading uplands and lowlands together.

The Problem with Buckthorn

There are several attributes of buckthorn that put it on the top of the invasive plant list which include:

1. Out-competes native plants for light, space and nutrients

2. Buckthorn fruit is readily spread by bird

3. Seeds may persist in the soil for up to 6 years before germinating 

4. Leafs out early in spring and stays green in fall longer than other trees

5. Thorns are dangerous and can injure persons in woodlands, parks and landscapes

6. Chemicals in its roots, leaves and fruit can inhibit the growth of other plants 

7. Vigorous trees that are difficult to kill even with herbicides

8. Creates a monoculture as it invades an area decreasing diversity of plant communities

 Key Elements of a Buckthorn Management Program

When deciding how to create and implement a buckthorn management program, there are several factors that must be considered.  These factors include budget, length of time that the buckhorn has been present, size and density of the buckthorn, season of the year and size of workforce (or number of volunteers). 

(1) The first phase of any buckthorn project would be to remove the medium and large buckthorn trees.  Also, the stumps must be ground out or treated chemically to minimize re-growth.  When dealing with a limited budget, remove the largest seed-bearing trees.  This phase can be started whenever, but optimum results can be achieved in the fall.

(2) The second step will be to pull or spray smaller seedlings.  The choice between pulling or spraying will depend on the size of the management area, the number of seedlings in the area, and if using chemicals is the right choice for you.  Some people would prefer not to use chemicals, but in larger areas it is often the most effective choice.

(3) Once the buckthorn is removed, there will be a flush of new sprouts from germinating seeds that have been lying dormant in the soil.  This is caused by an increase in light penetration to the soil.  During this phase, new seedlings should be sprayed or pulled. This phase could last several years.

(4) The fourth phase of management will vary depending on how severe the buckthorn has displaced the native plants in the area.  In some plant communities native plants will re-establish in time.  However, in many areas, the buckthorn will have displaced native plants for so long, replanting will be necessary.  This is a very important part of the restoration process.  Unless native plants can re-establish, it will be easier for buckthorn to reinvade.  Here are a few plants that can be used in the replanting phase of buckthorn management.

Trees; Ironwood, Pagoda dogwood, serviceberry, alder

Shrubs; Nannyberry viburnum, Arrowwood viburnum, dogwood, winterberry, hazelnut

Perennials; Jack in the pulpit, columbine, wild geranium, early meadow rue, lady fern