Is a 3 gallon grow bag large enough?

To support roots all the way through vegging and 12/12? Or should I invest in something even larger.

The more room your plant has to grow, the bigger it will be in the end. It depends really how big do you want your baby to be? I think 3 gal is a pretty decent size tho:cool:

3 gallon is a great size for finishing out flowering in but some use 5 gallons when they have the space to use it. I start seeds in solo cups, move to 2 liters and then to 3 gallons for flowering. I believe if you give the plant a fresh pot to grow out more roots during that 2 week stretch it does help with the overall health and vigor of the plant as well as provide more yield as an end result. Just my 2 cents. Take it or leave it.