But now is not the time to spray, said a range specialist with New Mexico State University. Broom snakeweed germinates when there is winter and early spring moisture, he said.
Seedlings appear in the early spring.
As livestock eat the plant, it affects their reproductive systems' resulting in abortions in pregnant females. Duncan suggests that ranchers and land managers wait to spray broom snakeweed for two reasons. The hot and dry summer weather usually kills the seedlings due to lack of moisture. Secondly, research indicates the best time to spray broom snakeweed is in the fall. The plant can be sprayed from the full bloom through the first part of December.