Marigold

Marigolds (Tagetes species) are easy to grow, economical, bloom reliably all summer, and have few insect and disease problems.
Barbara H. Smith, ©2020 HGIC, Clemson University

Marigolds (Tagetes species) are easy to grow, economical, bloom reliably all summer, and infrequently have insect and disease problems. They are a popular warm-season annual with bright, long-lasting blooms.

Height/Spread

Plant height varies with the cultivar. Marigolds cover a full range of sizes from about 6 inches to 3 feet tall.

Ornamental Features

Marigolds have cheery, pom-pom, anemone, or daisy-shaped inflorescences in colors ranging from yellow and gold to orange, red, and mahogany. Some unique cultivars have striped, bicolor, or creamy white blooms. The two main species grown in home gardens are the French marigold (Tagetes patula) and the African marigold (Tagetes erecta). French marigolds are more compact in stature, with smaller flowers. African marigolds are much larger, with blooms up to 4 inches across.

Marigold leaves are finely cut and fernlike. The foliage is a rich dark green and is often strongly scented, making them deer resistant.

Growing Marigolds

Marigolds are used for mass planting, edging, borders, cut flowers, and container plantings. Most varieties bloom from early summer until hard frost in late fall.

Marigolds require full sun and grow best in well-drained, loamy soil. Prepare flower beds by incorporating organic matter and cultivating the soil to 6 inches deep. For best results, amend the soil prior to planting according to the results of a soil test. For more information on submitting a soil sample for testing, see HGIC 1652, Soil Testing. Marigolds prefer a slightly acidic soil. However, at a soil pH below 5.5, marigold leaves may develop a bronze speckled appearance due to manganese or iron toxicity.

In the absence of soil test results, a slow-release fertilizer formulated for annuals can be incorporated at the time of planting. The ideal time to plant marigolds is after the last frost in spring. Space the plants according to the mature size of the cultivar. Space French marigold plants 8 to 10 inches apart, and space African marigold plants 12 to 16 inches apart. For information on how to prepare landscape beds for planting marigolds, see HGIC 1152, Growing Annuals.

Water marigolds well at planting and keep the soil evenly moist for the first couple of weeks until they become established. Marigolds grow well with about an inch of water per week. In the absence of adequate rainfall, water established marigolds deeply once per week, allowing the soil to dry somewhat between watering.

Remove the old flowers as they fade for continued bloom. African marigolds may require staking to prevent the plants from falling over during storms.

Marigolds can be purchased as transplants or seeds. Marigolds germinate quickly, are easy to grow from seed, and are an excellent choice for a beginning seed gardener. Start seeds indoors, at 70 to 75 °F, four to six weeks before the desired planting time. Start seed for African marigold cultivars indoors 8 weeks prior to planting outside. Alternately, once the soil has warmed and the danger of frost has passed, marigold seed can be sown directly into the garden. Plant the seed approximately ¼ inch deep and expect germination in 5 to 7 days. At the end of the season, seed can be saved from open-pollinated cultivars. However, it is best not to save seed from hybrid cultivars. The seed collected from hybrids may be sterile. Even if the seed is viable, the offspring of hybrids do not look like their parent cultivar.

Problems

Despite their reputation for repelling pests, some insects are attracted to marigolds. Spider mites can be a problem in hot, dry weather. Slugs, leafminers, aphids, whiteflies, thrips, and caterpillars can also cause damage. Marigolds are susceptible to diseases caused by viruses such as Tomato Spotted Wilt Virus (TSWV), Impatiens Necrotic Spot Virus (INSV), Cucumber Mosaic Virus (CMV), and the phytoplasma disease called Aster yellows. Viral infection symptoms include spots or rings on the leaves, chlorosis (yellowing leaves with green veins), or stunted/unusual growth. Viruses are typically spread by whiteflies, thrips, or aphids, while aster yellows is spread by leaf hoppers feeding on the plants. Fungal stem and root rots, fungal leaf spots, gray mold, and bacterial wilt are also occasional disease problems. For more information on managing these pests and diseases, see HGIC 2100, Gray Mold (Botrytis blight) and HGIC 2771, Insecticidal Soaps for Garden Pest Control.

Species & Cultivars

Marigolds are native to subtropical America and have been cultivated in Mexico for over 2,000 years. Marigold cultivars are usually sold as part of a series with similar growth characteristics and a wide range of colors.

African marigolds (Tagetes erecta) have large, double flowers and bloom from midsummer to frost.
Barbara H. Smith, ©2020 HGIC, Clemson University

African marigolds (Tagetes erecta): Also commonly called American marigolds, these cultivars have large, double flowers from midsummer to frost. African marigolds are excellent bedding plants. They can grow as tall as 36 inches and can be used as background plantings and cut flowers.

• ‘Antigua™’ series marigolds grow 12 to 16 inches tall. They are compact hybrids with a mounded garden habit with blooms covering the entire plant. The fully double, 3-inch flower heads bloom well above the foliage. The series offers flower colors in gold, orange, primrose, yellow, and a mix.
• ‘Big Duck’ hybrids are extremely heat tolerant and bloom heavily until the very end of the growing season. All three colors in the series won a 2019 All-America Selections (AAS) award for their garden performance, including gold, orange, and yellow.
• ‘Crackerjack’ is an open-pollinated mix. It has large blooms on 3-foot tall plants. The plants are less uniform in appearance than hybrid cultivars. ‘Crackerjack’ is a mix of gold, orange, primrose, and yellow.
• ‘Inca II™’ hybrids produce large, double flowers on stocky 12- to 14-inch plants. The series is available in gold, orange, primrose, yellow, and a mix.
• ‘Marvel II™’ hybrids have large flowers on well-branched plants that hold up well to weather. The series is offered in gold, orange, yellow, and a mix.
• ‘Vanilla’ hybrid has 3-inch, creamy-white blooms.

French marigolds (Tagetes patula) are small, busy plants with flowers up to 2 inches across.
Barbara H. Smith, ©2020 HGIC, Clemson University

French Marigolds (Tagetes patula): French marigolds are small, bushy plants with flowers up to 2 inches across. Their blooms are described as single, anemone, or crested according to their appearance and occur in yellow, orange, or mahogany-red shades. Single types have one outer row of petals. Anemone types have large, flattened outer petals and a ruffled center. Crested types have shorter, densely ruffled petals at the center that appear like a distinct central tuft. Plant height ranges from 6 to 18 inches. They hold up better in rainy weather than the larger African marigolds.

• ‘Bonanza™’ series marigolds grow only 10 to 12 inches tall. All blooms are double-crested. Colors include ‘Bee’ (burgundy tipped in yellow), ‘Bolero’ (gold with red tips), gold, ‘Harmony’ (mahogany with an orange center), deep orange, ‘Flame’ (an orange/burgundy bicolor), and yellow.
• ‘Disco’ is a series with single flowers. Colors include ‘Marietta’ (yellow with a mahogany center), orange, red, and yellow.
• ‘Durango®’ is a series of anemone-flowered marigolds. The plants are well-branched and reach 10 to 12 inches in height. Colors include ‘Bee’ (burgundy tipped in yellow), ‘Bolero’ (gold with red tips), ‘Flame’ (an orange/burgundy bicolor), gold, orange, red, tangerine, and yellow.
• ‘Hot Pak™’ series is extremely heat and humidity tolerant. Plants are extremely compact, reaching only 7 inches tall. Colors include ‘Fire’ (gold/burgundy bicolor), ‘Flame’ (an orange/burgundy bicolor), gold, ‘Harmony’ (mahogany with an orange center), orange, ‘Spry’ (mahogany with a gold center), and yellow.
• ‘Naughty Marietta’ is an open-pollinated cultivar with a single-flowered appearance. The blooms have yellow ray flowers with a mahogany base.
• ‘Super Hero™’ is a compact marigold series reaching 10 inches tall. The color ‘Spry’, with its maroon outer petals and golden center, was a 2018 AAS Winner. Other colors in the series include ‘Harmony’ (mahogany with an orange center), orange, ‘Orange Flame’ (orange/red bicolor with yellow tips), ‘Orange Bee’ (orange/maroon bicolor), ‘Yellow Bee’ (yellow/maroon bicolor), and yellow.
• ‘Safari’ series marigolds have 3-inch anemone-type flowers on compact plants. They grow to 14 inches tall. Colors include ‘Bolero’ (yellow with red tips), gold, orange, red, scarlet, tangerine, yellow, and ‘Yellow Fire’ (maroon with yellow tips).

Interspecific Hybrid Marigolds

• ‘Zenith™’ series is a result of a cross between the French and African marigold species. It reaches 14 inches in height and produces 2- to 3-inch double blooms. Colors include deep orange, golden yellow, lemon yellow, orange, red and gold bicolor, red, and yellow.
• Signet Marigolds (Tagetes tenuifolia): Small and bushy with fernlike, lemon-scented foliage, signet marigolds have leaves that are much lacier than those of other species. Small, yellow, orange, or rust-red single flowers cover the plants in summer. The flowers of signet marigolds are edible with a spicy tarragon flavor. If blooming slows during midsummer, shear back the plants by one-third to encourage additional blossoms when cool weather returns.
• ‘Gem’ series cultivars ‘Golden Gem’ and ‘Lemon Gem’ are the most well-known signet marigolds. They grow to 8 inches tall and are dense with tiny, bright flowers.
• 

  Mexican marigold (Tagetes lemonii) is a perennial shrub native to southwestern United States.
  Barbara H. Smith, ©2020 HGIC, Clemson University

  Mexican Marigold (Tagetes lemonii): This perennial shrub is a southwestern U.S. native and is hardy in USDA zones 8 to 11. The strongly scented leaves have an aroma that is similar to a mixture of lemon and mint. It reaches 3 feet tall and produces small, golden, daisy-like flowers in the spring and fall.

Spanish Tarragon (Tagetes lucida): This anise-flavored marigold grows 3 feet tall and blooms in fall with many small, simple flowers. It is an excellent substitute for tarragon, where the climate is too hot and humid for true tarragon to survive.

Irish Lace Marigold (Tagetes filifolia): This is a short plant with lacy leaves and tiny white florets. It is grown for the beauty and licorice scent of its delicate, dark green leaves.

Pot Marigold (Calendula officinalis): Pot marigold is not a true marigold. This cool-season annual is grown for its bright yellow and orange flowers. It can be planted for early spring bloom near the coast or spring or fall bloom in the rest of South Carolina. Pot marigolds are often grown as herbs.

Marigolds as Cover Crops

When planted as a cover crop, several cultivars of marigolds have been found to suppress root-knot nematodes. French marigold cultivars ‘Tangerine’ and ‘Single Gold’ (Tagetes patula ‘Tangerine’, and Tagetes patula ‘Single Gold’) have shown resistance to several root-knot nematode species. Intercropping marigolds for nematode control has not been found to be effective in protecting nearby plants and is not recommended. For more information on root knot nematode control, please see HGIC 2216, Root Knot Nematode Control in the Vegetable Garden.

Originally published 03/99