When a plant starts budding depends on the strain - some go by maturity and others by daylight length. Then you need to consider your enviroment and whether you'll have a long enough season to finnish the flowering before budrot sets in. You should've checked this out at the beggining of the season though so that you'd have the correct genetics for your grow.
Where did you get your seeds from so people know which purple haze you have?

ETA Your plant's looking nice by the way:rastasmoke: