Im kinda new but I've done my research and pretty much from what i read you can keep a plant in a vegitative stage for a really long time it all depends on you really. if you have a 1000w then I would veg the liven hell out of a few plants with that much light. I typically veg for 8-9 weeks sometimes 10 depending how greedy i feel and how big I want my crop to be, but Im using a 400w hps alongside a 100w mh and I currently have one huge mother plant and 4 clones going rite now so you should be able to fit a few more with 1000w. lemme ask tho why are you interested in just 1 plant under 1000w?