Few annuals are easier to grow than marigolds. They are native to South America, and have been cultivated in Mexico for more than 2,000 years, according to the Clemson Extension. Marigolds belong to the Compositae family, which means they are related to asters, daisies and sunflowers. These tough plants love heat and humidity, and they'll add spots of vivid color to your garden.
Marigold flowers come in a wide variety of colors: yellow, gold, red, orange, white and reddish-brown. In addition to solid colors, their blooms also can be bi-color or striped.
Marigold foliage is fernlike or feathery, sometimes lacy. They have a pungent odor. The plants, which grow very quickly, can reach from 6 inches to 4 feet tall, with a spread of up to 3 feet.
Marigolds should be planted in the garden after all danger of frost has passed. If you want to start them indoors from seed, count back 30 to 40 days from your final frost date and start them then.
Use marigolds for large amounts of colors in the garden, borders, containers and as edging plants. They are continual bloomers, hanging on until the first hard frost.
Marigolds require at least six hours of full sun each day. While not too picky about their soil, marigolds will flourish in well-drained soil with lots of organic matter. Add compost or leaf mold 6 inches deep in your flowerbeds.
Pests and Companion Planting
You should not have much trouble with Insects or diseases bothering your marigolds. Extremely hot and dry weather could bring spider mites, and extremely wet weather may lead to fungal stem or root rot.
Gardeners use marigolds in their vegetable gardens to keep away pests. French marigolds give off a substance that kills root-knot nematodes. Whiteflies, aphids and the Mexican bean beetle are supposed to be repelled by the scent of the marigold.
African marigolds (Tagetes erecta) bloom from midsummer to frost. They produce large, double flowers that can reach 5 inches wide. Some popular series include "Antigua," which grows to 15 inches tall with double, 3-inch blooms of orange or yellow; "Crush," which grows to 12 inches tall with 4-inch yellow or gold flowers; and "Aurora," a bushy type that blooms early in humid climates with a variety of colors.
French Marigolds (Tagetes patula) are dwarf, bushy plants that reach 6 to 18 inches. Despite their petite size, they stand up to rainy weather better than the African marigolds. Popular series include "Bounty," which loves humidity and heat; "Little Hero," which has 2-inch double flowers; and "Safari," which has anemone-like blooms 3 inches wide.
Signet Marigolds (Tagetes tenuifolia) are bushy and petite with lemon-scented foliage. They have delicate, small, orange, rust-red or yellow flowers. You can eat the signet marigold's flowers, which have a spicy tarragon-flavor, according to Clemson Extension.
Tangerine Scented Marigold (Tagetes lemonii) is a native of the Southwest. Its leaves smell very strongly of mint and lemon. It grows to 3 feet.
Irish Lace Marigold (Tagetes filifolia) has yarrow-like leaves and very small white florets. Its dark-green leaves have a pleasant scent.
Spanish Tarragon (Tagetes lucida) blooms in the fall. Also known as Mexican or Spanish tarragon, its leaevs have an anise flavor. According to Clemson Extension, gardeners often propagate it as a substitute for tarragon where the climate is too hot and humid for the true herb to survive.
Pot Marigold (Calendula officinalis) is not really a marigold but a calendula. It's a cool-season annual with orange and yellow flowers.