Q : Buckthorn has become a major problem throughout the state. Can planting native species help suppress the growth of buckthorn, especially after buckthorn is removed from an area?

A : Depending on the circumstances, restoring native plant species after buckthorn removal may help suppress the regrowth of buckthorn. Without follow-up control of resprouting plants and seedlings that emerge after initial control, buckthorn will come right back. Buckthorn seeds in the soil can remain viable for up to five years. As a result, it is essential to monitor and manage buckthorn stands each year to suppress its growth, and allow native plants to establish. The best time to cut and chemically treat the stumps is in late summer and throughout the fall. Control methods are available on the DNR Web site at http://www. dnr.state.mn.us/invasives/ terrestrialplants/woody/ buckthorn/index.html