I start all my vegetable plants indoors from seed about 6 weeks in
advance of planting them in my garden. I keep the plants under grow
lights for 16 hours each day. I use peat pellets to start my seeds and
then transplant the small plants into larger pots using potting soil
when they are about two weeks old. As for my garden soil, I mix
dehydrated cow manure, slow release all purpose vegetable fertilizer and
compost into the bed in the fall of the year along with some chopped up
leaves. Come spring, I just mix in a bit more slow release granular
fertilizer about two weeks before planting time. I have a compost
tumbler and must say that they work quite well. As my plants begin to
produce vegetables, I place some compost around each plant and renew it
about every two weeks. This seems to work very well for me as I always
have a nice crop most years depending on weather of course. I also make
sure my plants get a inch and a half of water each week.

Rich from PA Zone 5-6