Marigolds require moderately fertile soil, and full sun conditions in order to thrive. Sow directly in the garden, after danger of frost is past, or start indoors in seed trays 4 weeks before frost-free date, and transplant into the garden.
Spacing between plants will vary depending on the variety, yet one plant can easily grow a 6”-12” wide if flowers are kept trimmed and plants are given ample fertilizer to stimulate growth. Too much fertilizer will stimulate lush foliage, however, at the expense of flowers. Allow plenty of air circulation between plants to avoid rot in wet weather.
Marigolds are particularly practical in containers, as they prefer the soil to dry out in between watering, yet can also be finicky, and do not like water from overhead, so instead water at the base of the plant.
Marigolds are the ultimate deer-resistant plant, with a strong fragrance to the foliage and flowers that repels most invasive, while the roots repel nematodes under the soil. The foliage may be prone to gray mold or leaf spot, and powdery mildew, while young plants can often develop damping off disease if overwatered and not given ample air circulation between other plants.