Carrie Barre-LiBaire's Gardening Column

Down to Earth Gardening

When you purchase a home in the middle of winter, you have a general idea of how your landscape will look like once the snow melts. Spring uncovers some surprises, and it takes some time to learn about and become familiar with your new surroundings. In my case it took me over a year to realize that I had some undesirables in my yard-Buckthorn.

European or Common Buckthorn (Rhamnus cathartica) and Glossy Buckthorn (Rhamnus frangula) were brought to Minnesota from Europe and used as hedge plantings until their invasive properties were realized. Both of these species are classified as a “Restricted noxious weed”, which means that sale, transportation or movement is prohibited statewide. Buckthorn aggressively invades many natural areas, choking out our native trees and plants. Both types of Buckthorn have profuse amounts of black berries that birds eat and spread the seed. Buckthorn is easy to identify this time of year because the leaves do not change color and stay on much later than other small trees.

We purchased our home in the dead of winter. I could tell that there were Lilacs, Crabapples, and Evergreens, but that was about it. We had a hedge in the back along the property line, but I didn’t pay much attention to that. I had more important landscape challenges to conquer. The first fall I noticed part of the hedge turned a brilliant orange, so I figured it was Amur Maple-which is also on the Minnesota Invasive Plants list- and forgot about it. Another year goes by, and I’m busy fixing the lawn and creating gardens when I notice this tree about 10 feet from the hedge. It was an ugly tree, gnarly and disjointed. I noticed it had thorns, then (gasp!) black berries-this was the dreaded Buckthorn! Then I noticed that Buckthorn was mixed in with the Amur Maples and Lilacs. That thing coming up from the middle of the Forsythia-Buckthorn!

I haven’t tackled the hedge yet, (just got the okay from the neighbor that it could go) but as for the individual trees, I cut them down to the ground with a hand saw and that took care of it. In more naturalized areas, Buckthorn can be a real devil to eradicate. You may have to cut and then paint the surface with a high concentrate herbicide. This is best done when the tree is fully leafed out and temperatures are consistently above freezing. It is probably too late to do anything now, so look for small trees that still have green leaves with black berries and mark these trees for removal in the spring.

Recently, I wrote about maple decline and inadvertently stated that the “Autumn Blaze” maple is a cross between a sugar maple and a red maple. It is actually a cross between a silver maple and a red maple. Thanks to those savvy gardeners out there who caught the mistake, as you can tell by this article, sometimes I’m not as observant as I should be!

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