the only thing you need to do is drill holes on the bottom so extra water can drip out instead of staying on the bottom, which causes root rot. They seem to be big enough to hold till harvest. When you transplant, make sure that the soil in both containers are dry. When you transplant into the bigger container, soak the whole container, while making sure the excess water is properly drained. then let dry completely so the roots will branch out and reach for water, thus creating a strong base. then you can return to your normal watering schedule.