Make the pot at LEAST 4 gallons. You can transplant them whenever you think they're ready. I had a LOT of trouble getting my seeds to germinate, out of two batches I got one viable sprout, and she decided to be a good girl. She's one of my biggest plants despite not being germed til early June, then went into her own dixie cup June 9th. She did put on her big girl panties just over a month later on July 18th, but I can't remember how many nodes growth that was, the cups were falling over in the wind.
She was going all organic!
She's not huge, I've made mistakes, not fed when I should have, what I should have. I now have a plant that's close to 3' tall (I expected that when I topped her, and she's begun flowering so there's just not as much "size" growth) and doing pretty well. The large pot helps her deal with heat issues, and I just think she likes having big shoes (as hydrotech likes to put it) on. I'm debating going with 4 or 5 gallon pots for this next phase (I've some clones).
Now, the plant's not huge, this is my first really successful grow, but I'm learning a lot as I go along. I did learn to use fertilizers/tonics/nutrients with mycorrhizae. I saw EXPLOSIVE growth when I began using this stuff. I currently use a combination of a Hippie Juice called Super Plant Tonic (found on eBay as Blue Mountain Organics, and they now have a whole product line I hear is very, very good), completely organic. And I was using Dr. Earth Organic 5, but in looking at the FF Happy Frog decided that since their product has higher P levels and the Mg, it would better suit my garden's current needs. All gets dosed with mycorrhizae up until three weeks or so (don't quote me, Ohsogreen's the one to talk to on how to finish with this stuff) before flowering finishes.
I tell you what, I've taken a bunch of clones, but I've just heard of "re-vegging" and if I could keep somma the girls with whom I've developed a relationship.... Some of 'em, they're a coupla pains in the ass, I'll be glad to cut their roots! So demanding, high maintenance, I tell you what. But there are others who I think might be some really good smoke, and they sure are pretty to look at.