Buckthorn seedlings

Many folks involved in restoration work are familiar with buckthorn (Rhamnus cathartica), a really bad invasive shrub that is especially hard to get rid of. There is quite a bit about buckthorn eradication on this web site. But have you ever seen buckthorn seedlings?

The photo below shows a spread of buckthorn seedlings growing out of a pile of mulch that had been brought in for restoration purposes (fortunately, not at Pleasant Valley Conservancy). You would think they would know better, but many landscape architects are guilty of such acts.

In Wisconsin, one of the missions of the Wisconsin Crop Improvement Association is the promotion of mulch certified to be free of noxious weed seeds. Although this is a voluntary process, users can use WCIA standards to ensure the quality of their mulch.

Weed-free topsoil would also be desirable, but is much harder to arrange. The only certain way is to use sterilized soil, an expensive proposition. (A large autoclave is needed to sterilize any reasonable quantity of soil.)