Buckthorn has become a major invasive problem for many of my clients over the past few years. Many people ask me how to control the buckthorn in their yard. Late fall and early winter can be a good time to control buckthorn, weather permitting. If you have a small yard you could complete the task all at once. If you have a larger yard or more than 15-20 plants to cut down, then I would recommend you work in stages doing sections every year.
I found a site online that will give you some great information from the Minnesota Department of Agriculture the pdf they provide can be found at: www.mda.state.mn.us/new/publications/pestplants/buckthornfactsheet.pdf nnnnnn47hh
A brief summary of this article:
The buckthorn most commonly found in our area has the botanic name of Rhammus cathartica or European or Common Buckthorn. The European or Common buckthorn was imported by the early settlers in the mid-1800’s for use as a hedge plant. It has become a problem invading both woodland understories and field/prairie edges. It is both drought and shade tolerant. It is spread rapidly by birds feeding on the fruit. Common buckthorn grows to a height of 20 feet with an equal spread and irregular crown. The bark is rough grey/brown with horizontal white marks similar to a cherry tree. The fruit is glossy black 3/8” in diameter in dense clusters at the stem junctions, along the branch, and at the ends of the branch tips. Many of the stems have berries, but some do not, and you will have to ID the plant by the thorns on the stems, the buds on the branch stems that are almost opposite on either side of the stem, or the dark green leaves that stay on the shrub in fall longer than many native plants. When the stems are cut near the ground the wood color is a yellowish-brown-green not white like many of the native hardwood trees.
There are several methods used in removal of the plant: cut stump treatments, bark treatments, foliage treatments, fire, or mechanical removal. This post will discuss only the cut stump method using Tordon RTU. I have used Tordon for a number of years at our woods up north. It has been effective in killing the buckthorn stumps and can be applied very selectively to only the stumps which helps minimize the risk of killing other native species in the immediate area. It is important to follow the directions on the label and use all the recommended safety precautions and wear the proper protective gear. After you have gone thru the plant ID process, cut only a small number of stems or trunks, leaving a 2-3 inch stump, remove the cut material from the cutting area, and apply the Tordon with a brush to the freshly cut stumps. It is important not to cut too many stumps at once or you will miss some when trying to apply the Tordon. Moving the cut material away from the stumps will help you locate the fresh cut stumps. It is important to apply the Tordon to a fresh cut stump because this helps in the absorption of the Tordon.
Tordon RTU is a nonrestricted use herbicide, you do not need a special license to buy or use it. It can be purchased from Reinders in Waukesha in a 32 oz. container. The active ingredients are picloram @54% and 2,4-D @ 20.9%. Always pour a small amount in a small container and brush on the stumps using a paint brush. I do not spray the material in order to avoid over application. The advantage of Tordon is that it is ready to use with no mixing required, inexpensive, highly effective, and can be used year round. As long as you keep it sealed and do not let it freeze one container can last many years. The disadvantage of the product is that it can move through the soil and can kill non targeted plants, over application can contaminant ground water and it can persist in the environment.
The only problem in using the stump cutting method is the amount of waste that can be produced in cutting all the stems to the ground. Many cities have a brush pickup or drop off site. With larger projects the movement of material becomes impractical and a chipper might be needed to get rid of the waste. Buckthorn will burn in a hot fire if you harvest the larger stems and trunks for firewood. If you have trunks larger than 12 inches in diameter, call me, I have a source that will purchase them.
Buckthorn has become an invasive species that will continue to change the native habitat unless it is brought under control. Removal can be a daunting task for any do-it-yourselfer, taking the time to do this in small sections will make it much easier to accomplish. Give me a call if you need additional information or help with this plant.