i was wondering if you could germinate the seeds then put them straight into a 4 gallon pot and leave them in there until harvest, instead of transferring which i haven't attempted before. : ) thanks
Yes, tons of people do. Some guys on here say that starting in smaller containers, letting the roots almost fill it, and then transplanting will help develop healthier and more dense root systems. I also have seen many experienced growers say that it doesnt matter, that having one big pot allows the roots to expand to any area they want to. I agree with the latter more. Short version: Four gal is fine, You will harvest some nice ladies.
Starting in a smaller container makes it easier to gauge your watering needs than in a large pot. For watering MJ you should water thoroughly when you do then not at all until the soil dries out a bit. In a large container the soil is deeper so doesn't all dry at the same time, and yet a young plant will still have relatively shallow roots, making it harder to know when the soil is properly dried out -- but not over-dried -- for your plant. I've been growing for years and still start in 4" pots before transplanting to the 5 gal buckets, partly out of habit but also I tend to stick with what I know works. I don't see a need for more than one transplant to manage root growth, and transplanting is easy-peasy.