Marigold Development

General

• To make sure your marigolds develop properly, plant them in a well-drained site that gets full sun. You can sow directly from seed or use transplants. For the best flower development, pinch back spent blossoms. Avoid fertilizing your marigolds. This might increase the plant's foliage but inhibit flowering. Marigold flowers bloom in a wide variety of colors, including orange, gold, red and yellow. Make sure your plants receive at least 1 inch of water per week, whether from rainfall or manual application.

African

• African marigolds grow taller than most of the other most widely grown marigolds and develop double flowers. Double flowers occur when a blossom has extra petals, giving the blooms a fuller appearance than most flowers. The large flowers of the African marigold might grow 5 inches wide. The foliage of the plant gives off an unpleasant scent. Growers have developed cultivars from the African marigold, including the "Aurora" series of plants, which thrive in humid, warm climates, according to the Clemson University Extension.

French Marigolds

• French marigolds, botanical name, Tagetes patula, develop differently from African marigolds. French marigolds typically do not grow as tall as Africans and their flowers grow only about 2 inches wide. Also, the blossoms might appear as either double of single flowers and individual bloom might be single-colored or bicolored. French marigolds have a compact and bushy growth habit. Growers have also developed many cultivars for French marigolds.

Signet

• Signet marigolds develop a rounded, pleasing shape as they mature and have much smaller flowers than the French and African Marigolds. The attractive leaves give off an appealing aroma, according to "Southern Living" magazine. Signets grow about 1 foot high and have edible blossoms. The plant might have trouble developing flowers during periods of high temperature. Pruning the plant by one-third can help it bloom again when the high temperatures subside.