Gather your planting supplies about six weeks prior to the last projected frost date in your region if you plan to transfer the celosias outdoors once they germinate.
Fill the peat pots about three-quarters full with potting soil or seed-starting mix.
Sprinkle the top of the pots lightly with warm or lukewarm water.
Place three or four seeds in each peat pot and then cover very lightly with potting soil or the seed-starting mix. The seeds should be about ¼-inch deep in the soil.
Cover the peat pots with plastic wrap and place the pots in a warm, sunny place away from drafts.
Remove the plastic every day for about one hour to give the plants a chance to breathe.
Keep the soil moist but not soaked with warm or lukewarm water until the seeds germinate. This should take between 10 days and two weeks.
Pinch and remove all but two of the strongest, more virile looking leaves once the seeds have germinated.
Begin to “harden off” the plants to prepare them for the transition from indoors to outdoors. When daytime temperatures reach 60 degrees, start leaving the plants outdoors in a protected area for several hours a day. Add two hours a day for a week until you can safely leave the plants outdoors overnight.
Transplant the peat pots directly to your garden, or to a container, when the soil temperature reaches at least 60 degrees, scattering the pots in a creative, clustered manner. Avoid planting them in rows, like soldiers. Water and fertilize the plants with a slow-release water-soluble fertilizer.