Want Gooseneck Loosestrife Gone

Asked August 27, 2013, 3:22 PM EDT

What is the best way to eliminate white gooseneck loosestrife? We have it in a flower garden with many other varieties of flowers and it is taking over. We tried digging it out but that was far from successful.

Hennepin County Minnesota

1 Response

Glyphosate herbicides are very effective for killing loosestrife. Glyphosate is available under the trade name Roundup. Glyphosate is nonselective; however, selective application techniques allow it to be used effectively with minimum damage to desirable plants. It is taken up through the leaves or young stems and will kill any plant that it is applied to. Therefore, treat only the loosestrife plants and avoid contact with valuable plants.

Glyphosate is biodegradable, very short-lived and becomes quickly inactivated when it contacts moist soil. The overall objective when controlling loosestrife with glyphosate herbicide is to spray very carefully so the loosestrife plants are selectively removed but the surrounding desirable vegetation are not harmed. If this can be accomplished most of the loosestrife will be controlled.

Follow-up treatment is needed each growing season since some plants will be missed, new seedlings will sprout, and a few plants will survive the initial treatment. Improper mixtures and careless application, however, inevitably kills more surrounding vegetation and leads to the establishment of more loosestrife seedlings. Roundup can be applied with a small paintbrush if spraying is not an option. Cut the stem and apply roundup directly to the cut stem avoiding plants you want to keep. Read and follow the directions carefully.