We use the following technique to grow seedlings for transplanting with excellent results. Although we use it in semi-arid New Mexico, it should work equally well in other parts of the country. We use greenhouses for our growing environment.
About 8 weeks before transplanting, prepare 6-pack cells by filling them with the suggested growing medium, and place the cells in the plastic trays. Place the trays on the heating cables and plug in the cables. Water the cells with a diluted solution of 20-20-20 fertilizer (1/2 teaspoon in 1 gallon of water) or a slow-release fertilizer like 10-10-10 because the medium has virtually no nutrients.
Select the seeds according to the criteria above and use a pre-planting treatment if you wish. With a stick or the eraser end of a pencil, punch a hole in each cell 1/4-inch deep. Drop two or three seeds in each hole, then cover them with the planting medium. In each six-pack, insert a plastic tag with the variety name and the date marked on it in permanent ink or pencil. Some growers keep a journal in which they record the variety name, date, number of seeds planted, and later, the germination percentage and other notes on the progress of each variety.
When the seeds sprout, cull all but the most vigorous seedlings from each cell by clipping them at the base with scissors. Gently water the cells from the top and make certain the cells are kept moist, but do not allow water to sit in the trays and keep the mixture soggy. If the seedlings are stressed at all by drying out or wilting, it will be difficult if not impossible to revive their normal growth. Make certain there is adequate ventilation and air circulation in the growing enviroment. Fertilize the cell-packs once a week with the same mixture described above.
In a heated greenhouse, the heating cables can be turned off after the seeds have sprouted. But, in a cold frame where the only heat is from the cables, the cables should be kept on until the nighttime temperatures warm above freezing.
Cigarette smokers should wash their hands with a strong soap or with rubbing alcohol before touching the seeds or seedlings. The tobacco in cigarettes may contain tobacco mosaic virus which can infect the pepper seeds or plants.