The hardy weeds are not only blooming, they are beginning to set seeds. But don't panic. Mustard weeds are relatively easy to control, Phillips says. They are not highly allergenic, and the city has a weed-cutting plan in place. Winter moisture and cool soil created ideal conditions for seed germination, Phillips says.
Seed pods form from the flower, and the weed continues to put out flowers for a period of time.
Most mustard weeds will have begun dying out in May, about the time kochia and Russian thistle begin to dominate the local weed scene, Phillips says. Fortunately, most of the pollen produced by mustard weed is carried off by bees and other insects, rather than being carried off by the wind. The key to controlling the spread of mustard weed is to stop it from going to seed and avoid disturbing the soil in the process, says Phillips. It's best to wait until the weed flowers. Once the weed is cut, it should be removed from the ground to prevent it from eventually reseeding.