HOW TO PLANT SNAPDRAGON SEEDS Start indoors by sowing the seed into seed substrate, as opposed to soil, and compress firmly. Don't cover as Snapdragon seeds require sunlight to germinate. Keep moist, and place trays in a warm, sunny location. Grow lights can be used, as well, giving the seeds about 16 hours of light exposure each day. You should see germination in 10-14 days. Thin to one seedling per cell/pot once they've developed two leaves. Keep seedlings at a steady temperature of 60-70ÂF. HOW TO CARE FOR SNAPDRAGON Transplant Snapdragons after the final frost of Spring. Give Snapdragons a spacing between 6-12 inches to ensure they have adequate room. Pinch off the tips once the Snapdragons have 6 leaves, to encourage richer, fuller blooming. Once Snapdragons die back in the fall, cut them down and remove the debris from the growing area.