Keeping weed propagules out of the greenhouse by using sterile media, introducing only clean plant materials, and weed control outside of the greenhouse. Where possible, screening vents and windows will limit the introduction of wind blown seed as well as insect movement. Concrete or mulched floors will also limit weed establishment. Some weeds will get into the greenhouse. These should be removed manually or by herbicide treatments before going to seed.
Continuous removal is expensive and time consuming.
Currently there are no residual herbicides labeled for greenhouse use. Where weeds are a continual problem, clean up the area, removing the soil or covering it with a mulch. Only under extremely rare circumstances would fumigation be recommended for weed control. Herbicides labeled for greenhouse weed control Trade names used herein are for convenience only. No endorsment of products is intended, and no criticism of unnamed products is implied.