Once garlic mustard is bolting and flowering, herbicides are a waste of time and money. Plants will rally back, even after several rounds of herbicide application. Provided siliques (seed pods that look like a miniature green bean pod) have NOT started to develop, options for control at this stage include:
1. HAND-PULL GARLIC MUSTARD
Be sure to remove the entire S-shaped tap root to avoid re-sprouting. Gently shake all soil loose from the roots. Excess soil on the roots or any ground contact will allow garlic mustard to re-sprout even though it has been uprooted. Place small bundles of pulled plants where the roots will have NO soil contact. Ideal placement may be the crotch of a tree or shrub, roots facing upward for maximum sun contact. A large fallen log or metal culvert would also be appropriate locations to leave the plants to dry out, decompose and return nutrients to the soil.
2. MOW OR WEED WHIP GARLIC MUSTARD (temporary fix)
As in the option above, do NOT consider this option if siliques have started to develop. Note that this option is not a permanent solution but will buy you time if you have not been able to complete the task of hand-pulling blossoming garlic mustard plants before seed pod/silique formation starts.
Next blog: What to Do with Garlic Mustard after Seed Pods Start to Develop.
Spread the word, not garlic mustard. Educate others about the importance of garlic mustard control.