When Do I Transplant

So my plant is 20 days old today. A Fast Bud Autoflowering plant. I have it in a pot that is 8" in diameter and about 8 inches tall. The plant itself is 4" tall (picture included). My question is at what point will this pot start to cramp the roots? I want to transplant before the growth becomes stunted.

Thanks.

Well, it'll be quite awhile before you have to worry about that, because it is growing pretty slow right now. It's tough to say exactly, but, I veg mine to 18" sometimes,(when I transplant to 10" or 12" pots) use 6" pots, and although they are getting close at that point, never ran into problems with them being rootbound.

May I suggest that you look into the culprit of the slow growth? It's tiny for a 20 day old plant, even if it's a strain that doesn't grow that large. If you get some free time later, start a new thread and include the details of your setup, and I'm sure you'll get some help that'll get your baby up to speed.

agreed, what type of lighting and how far away is it? how often are you watering?

gotta be weak lighting

You need more lighting ASAP, probably in the next week or two. Then worry about roots.