By Lyle Pyeatt, July 1985

In spite of such misleading and commonly used names as African Gold and French marigold, these plants are native to the Americas. The distribution of wild marigold species ranges from Arizona and New Mexico through Central America to Argentina.

The marigold is an immensely popular warm season annual, and rightly so, because it has many positive qualities and few potential problems. No other plant is faster or easier to grow. Flowers are produced over a long period of time and are long lasting when used as a cut flower. There is a whole spectrum of interesting and different cultivars from which to choose.

Marigold types:

African or American (Tagetes erecta): These are tall, erect-growing plants up to three feet in height. Hybridists have also produced some dwarf cultivars (for example: 'Cupid' and 'Guys and Dolls') The flowers are globe-shaped and large, to five inches across. Red flower colors do not appear in this group, but there now are white-flowered cultivars. The Africans take longer to reach flowering stage than the French type.

French (Tagetes patula): Cultivars in this group grow 5 inches to 18 inches high. Flower colors are red, orange and yellow. Many cultivars combine red and orange in different bicolor patterns. Double-flowered cultivars predominate, but there are a number of others with single, daisy-like flowers. Flowers are smaller than those in the African group.

Species: This group probably is not as far removed from their wild ancestors as the much hybridized African and French types. Plants form compact, low mounds less than 12 inches high. Two species offered in the trade are described below.

Tagetes tenuifolia 'pumila' (T. signata 'pumila'): The signet marigolds produce compact plants with finely divided, fern like foliage and masses of small, single flowers. 'Lemon Gem', 'Lulu', 'Paprika', 'Silva', and 'Starfire' are signet marigold cultivars.

Tagetes filifolia: 'Irish Lace' is the common name of this species. The leaves are finely and delicately divided. The white flowers are minute in size.

Triploid: These are hybrids between dwarf French and tall African cultivars. Most triploid cultivars grow from 12 to 18 inches high. In addition to combining qualities of the two different parental types, the triploids are sterile and incapable of producing viable seeds. Since none of the triploid plant's energy is directed to seed production, flowers are produced in profusion over a long period. Seeds are expensive and the germination rate is rather low.

Sources

Your favorite garden center/nursery sells plants in containers and packets of seed of some cultivars. Mail order seed companies list many cultivars.

Flower Color

Red, orange, yellow and even white.

Uses

Dwarfs are excellent for edging walkways, flower beds and borders. Intermediates (12"-24") are useful in massed plantings and mixed flower borders. Tall cultivars are good for background use in beds and mixed borders. Taller growing cultivars can be planted in rows in the vegetable garden or a cutting garden for use as cut flowers in the home.

Nematode Suppression

Research at the University of Georgia has shown that certain French marigold cultivars (Tangerine', 'Petite Gold', 'Petite Harmony', 'Goldie', and 'Nemagold') are effective in reducing root knot nematode populations in the soil when planted closely spaced in a solid block.

Culture

Grow in a sunny location in moderately fertile soil and water in moderation. Over fertilization and excessive soil moisture can result in too much foliage and not enough flowers. Marigolds are tough, don't give them too much "T. L. C.". Plant the low and intermediate height cultivars 6 to 12 inches apart. Space the tall Africans 12 to 18 inches apart. The tall cultivars may require staking, particularly if they are watered overhead or if they are planted in a windy area.

Starting From Seed

If you don't find plants of your favorite cultivars at nurseries and garden centers, or if you like to grow your own plants from seed, consider this: Sow seed in containers in spring. Transplant to recycled six plant packs or similar containers when the seedlings are large enough to handle. When the seedlings are well established and beginning to crowd each other in the six packs (i.e. 3 to 4 weeks after transplanting), plant them in their permanent location. An alternative to starting the plants in containers is to sow the seed outdoors in a permanent location. After the plants have germinated, thin to the proper spacing for that particular cultivar. If you provide optimum growing conditions the triploids and many French cultivars will begin to flower seven to nine weeks after you sow the seed.

The Marigold Odor

People who object to the strong scent of marigolds may be pleased to know there are odorless cultivars ('Sweet'n Gold', 'Sweet'n Yellow', and 'Odorless Mixed'). However, availability may be restricted to one or two mail order seed sources.

Troubles

Marigolds are subject to far fewer insect and disease problems than most annual flowers. Be especially watchful for the "night raiders", i.e. snails, slugs and earwigs. Young marigold plants can rapidly be consumed by these pests.