Remaining weeks/days (3 plants)

No, you don't have to do it all at once.. but i would be a bit concerned if there is a very long delay from first to last --- dead rotting roots? how long before they die? as long as that isn't an issue, shouldn't be a problem. It will remain alive awhile after it has been chopped down, so there's definitely some leeway there. Think the middle pic is showing a new wave of pistils vs original growth? if trichomes look good on the non-new calyxes, it might be ready soon. the others look like they have a while left.. the calyxes are not plump around the pistil - giving the illusion they have shortened, but really it's the plumping around it that is the cause. they do die and coil up of course... a good chunk of them should be by the end.