Dogfennel is an aggressive native perennial plant, and is currently the most common pasture weed in Florida. Studies have shown that significant loss of forage occurs if Dogfennel is not removed prior to July 1st. Additionally, while cattle will not normally consume this weed, the leaves contain a toxin that results in dehydration. Overwintering rosettes begin to grow as temperatures increase, and seeds will also start to germinate (April-June) and seed dispersal will begin November-December.
There is no specific timing to herbicide control of dogfennel. Instead, plant height should be the deciding factor. Smaller plants are easier to control. See Dogfennel: Biology and Control for more infomation.