The small, single flowers literally cover the plants in summer. Flower colors range from yellow to orange. They also are edible. The flowers of signet marigolds have a spicy tarragon flavor. The foliage has a pleasant lemon fragrance.
Signet marigolds are excellent plants for edging beds and in window boxes.
The varieties Lemon Gem, Golden Gem and Tangerine Gem do well in Iowa. There are basically three marigold planting options available to home gardeners. Marigold plants can be purchased at greenhouses and garden centers. Other options are to sow marigold seed outdoors when the danger of frost is past or to start them indoors 6 weeks prior to the last frost date. Planting site requirements for marigolds are full sun and a well-drained soil.