You can prepare a light, loose soil mixture of your own. In this the tiny hairlike roots of new seedlings can easily work their way through and absorb the nourishment necessary for their development. Equal amounts of coarse sand, peatmoss or leafmold, and soil, make a good mix. If your soil is on the sandy side, you will find that two parts soil, two parts peatmoss or leafmold, and only one part sand will make a better growing medium than the equal thirds.
Sterilize your soil mixture or drench it with a fungicide to prevent damp-off of seedlings. Spores of this fungous disease apparently are present in all soils, and the moisture necessary for germination of seed and growth of seedlings provides the ideal condition for development of the fungus. Damp-off is practically impossible to control once it gets started in a seed-bed. Surgically clean tools and equipment are essential; drafts and sudden changes in temperature are to be avoided. Add no fertilizer to your soil mixture. Seeds contain the nutrients to carry them through to germination.