it's a real pain with these because the colas dont really get that dense, finished feeling like normal strains. Ive noticed they start to turn yellower by the day and really show their colors when theyre in the last week or two. and about the old growth turning brown thats wierd. is it the buds or leaves? if its theleaves then you're all good, but definitely got a problem if its nuggz.-edit- nvm i saw the budworms. i'd say you have another month. another piece of advice from me is that with these types of sativas you will have a lot of amber trichs at harvest because they have such a long life, just wait until there are almost no clear trichomes then cut it if its ready. those are gonna be some tasty-frosty nuggz man!