Now this may sound like another stupid question, but I haven't seen any threads or post on how long exactly you can keep a mother plant in a vegitative state to use for cloning and how do you keep the mother from getting to tall or big? exspecially when you are doing an indoor grow (space limited)?
Of course, don't switch to 12/12 lighting. To keep her small, just use a small pot and trim her every now and then (you will be anyway if you're taking clones). After a while it might be necessary to trim the roots too, but be careful with this. I think there's a thread on here about bonsai mothers, try a search.
thanks for the response, just looking to keep a good mother plant around for awhile for some cloning.
Yup, what was stated above. A mother plant will grow indefinitely given the proper circumstances. But who's got the resources to grow a giant Cannabis tree indoors? Trimming likely won't be a problem, depending on how many clones you need to take. You'll also want to do some root pruning when it gets rootbound. You can accomplish this by watering the pot half an hour before hand. Then find a place that can be easily cleaned or go outside. Pull up the whole rootball. You want to use a sharp knife to cut sections off of it. Once you've reduced the size of the rootball about 40% or so, transplant back into the pot with fresh damp soil. Sometimes a small haircut also helps the process. If you don't prune the roots, you're going to encounter problems with your nutes and/or pH. Happy growing!