Start marigolds inside several weeks before the last frost by planting seeds in seedbeds. Transplant the seedlings into individual pots and then move them to the garden after the danger of frost passes. Marigolds have large seeds that are easy to germinate.Continue Reading
Some marigold varieties take 45 to 50 days to bloom, so start the plants indoors several weeks before the final frost is expected. Plant the seeds in protected seedbeds, cover them with 1/4 inch of vermiculite and water the seeds. Keep the soil moist and in a warm location.
Transplant the seedlings into flats filled with loose dirt when they reach 2 inches in height.
Once the danger of frost passes, move the marigolds to the garden. Prepare the soil by turning it to a depth of 6 inches, and removing any rocks. Mix 5-10-5 granular fertilizer into the soil before transplanting the plants. Add 2 inches of organic mulch around the plants while they are young. Apply water to the base of the plants when you transplant them and during times of drought, but do not feed marigolds. Feeding them encourages growth of foliage while discouraging flower production.