GMSgrowsanswered grow question 4 years ago If you use a bud boosting formula like massive bud formulation, then if you don't like fox tailing, you need to stop using it earlier than your normal bloom ferts. Fox tailing is a trate of bud stimulants. When my buds reach the 6th actual flowering week, not including the stretch period is when I stop using the bud stimulant.