I agree, start them indoors and move them outdoors when they have 4-5 sets of true leaves. Outdoors it's often hard to keep them on a regimented feed schedule due to periods of rainy weather, so I would suggest a soil mix that contains some good organic material like worm castings, composted manure or guano. That way the plants can feed off the soil instead. A mix of sphagnum peat moss, perlite and organic material, plus some dolomite lime to buffer the pH of the soil, and some mychorrizal fungi to stimulate root growth.