Wedding Cheesecake | First growing exp.

You should not harvest yet. I have the impression that you're looking at the trichomes on the leaves and not in the flowers. As for a partial harvest, don't bother with that, the plant will be too stressed by the pruning and you'll be wasting energy on buds that are too small. However, for your next crop, remember to prune all the little flowers at the bottom of the plant that won't give a great yield. This will allow the plant to concentrate its energy on the big flowers at the top.