Well I only applied HST in week 8. But my plant is way more advanced weeks ago than she should have been. Very odd, but point is, let some form of bud grow on it don't apply HST too early. I'd do it no later than 4-5 weeks left so she can heal on a normal growing plant, mine was done cause it's just an odd plant. HST on autos is something that really shouldn't be done. But fem once you leave at least 5 weeks with nutes so 6-7 with flush. So if you flush for 1 week start at least 6 weeks before expected harvest. Happy growing.