The foliage has a pleasant lemon fragrance. Signet marigolds are excellent plants for edging beds and in window boxes. The varieties Golden Gem and Lemon Gem do well in Iowa. There are basically three planting options available to home gardeners when planting marigolds. Marigold seed can be sown directly outdoors when the danger of frost is past or started indoors 6 weeks prior to the last frost date.
Marigolds are also available as bedding plants at garden centers.
Planting site requirements for marigolds are full sun and a well-drained soil. Plant spacing varies from 6 to 9 inches for the French marigolds and up to 18 inches for the taller African marigold varieties. Summer care of marigolds is simple. Water occasionally during dry weather and pinch off faded flowers to encourage additional bloom. Tall African marigolds may require staking to prevent the plants from falling over or lodging during storms.