|I planted eggplant and tomatoes in Burpee seed-starting kits, and want to know if I am going to have to transplant these to other pots, or if they can stay in the kits till I'm ready to plant in the garden.|
|It depends on how big the plants get--if they get to big for their pots, they'll become pot bound and the roots will be crowded, slowing growth.
As a rule of thumb, plant tomatoes and eggplant 6 to 8 weeks before the last frost date. Your last frost date is around late April/early May, so you probably could have waited a bit to plant the seeds. They may indeed outgrow the containers by the time the garden is ready for them. If they roots begin to fill the soil block, simply transplant to a slightly larger pot.