Marigolds

How to Plant, Grow, and Care for Marigolds

Marigolds, French
Pixabay

No annual is more cheerful or easier to grow than marigolds. These flowers are the spendthrifts among annuals, showing a wealth of gold, copper, and brass into our summer and autumn gardens. The flower’s popularity probably derives in part from its ability to bloom brightly all summer long.

Marigolds have daisy-like or double, carnation-like flowerheads and are produced singly or in clusters. Although there are some 50 species, most marigolds we know come from just three:

  • Tagetes erecta are the tallest and most upright, at three to five feet. They are sometimes known as African, or American, marigolds. They thrive under hot, dry conditions.
  • Bushy T. patula, or French marigolds, are somewhat smaller and more compact. They are often wider than they are tall. Elegant and eye-catching, they have relatively demure flowers and usually grow from 6 inches to 2 feet tall.
  • The dainty T. tenuifolia are the signet, or rock-garden, marigolds that like hot, dry sites and make a wonderful edging. Their flowers are edible.

Marigolds have been sterotyped, but they offer tremendous variety. Both the African and French marigolds are generally aromatic, too.

French and signet types can be planted anytime through midsummer, but the tall American marigolds are best planted right away in the spring (after danger of frost is past) because they are slower to mature.

Planting

  • Marigolds thrive in full sunshine and can often withstand very hot summers.
  • Though they grow in almost any soil, marigolds thrive in moderately fertile, well-drained soil. Prepare the soil by digging down about 6 inches to loosen it. Remove stones. 
  • Optional: Add some granular fertilizer in the planting hole. A 5-10-5 works fine.
  • Sow them directly into the garden once the soil is warm. You can start seeds indoors but they germinate so easily outside that there’s really no advantage. Marigolds sprout within days in warm weather and plants bloom in about 8 weeks.
  • Sow seed 1-inch apart. While still small, thin the seedlings. Space French and Signet types 8 to 10 inches apart. Larger American varieties should be at least 10 to 12 inches apart.
  • After planting, thoroughly water each plant.
  • Separate seedlings when they are about 2 inches tall. Plant them in flats of loose soil, or transplant them into the garden.
  • If planting in containers, use a soil-based potting mix. Either mix in slow-acting granular fertilizer at planting time or plan to water in diluted liquid fertilizer periodically. Take care to space properly; marigolds grown in containers can become crowded.

Yellow marigolds

Care

  • Germination from large, easily handled seeds is rapid, and blooms should appear within a few weeks of sowing.
  • Marigolds don’t require deadheading, but if the spent blossoms of the American type are clipped, the plants will continue to bloom profusely.
  • When you water marigolds, allow the soil to dry somewhat between waterings, then water well and repeat the process. Water in high heat. 
  • Do not water marigolds from overhead. Water at the base of the plant. 
  • Do not fertilize marigolds during growth. Too rich a diet stimulates lush foliage at the expense of flowers. 
  • The densely double flowerheads of the African marigolds tend to rot in wet weather.
  • Add a layer of mulch between plants to suppress weeds and keep soil moist, especially when plants are young.

Pests/Diseases

Farmers and gardeners have long known that marigolds make important companion plants all over the garden. The underground workings of the marigold will repel nematodes (microscopic worms) and other pests for up to 3 years.

Marigolds have few pests or problems. Mites and aphids sometimes infest marigolds. Usually a spray of water or an insecticidal soap, repeated every other day for a week or two, will solve the problem

Occasionally marigolds will get a fungal infection if it’s often wet. Avoid watering on the leaves, keep weeds down, and plant in well-drained soil. 

Harvest/Storage

  • In flower arrangements, strip off any leaves that might be under water in the vase; this will discourage the overly pungent odor.
  • Marigolds can be dried for long-lasting floral arrangements. Strip foliage from perfect blossoms and hang them upside down.

Recommended Varieties

Wit & Wisdom

  • In the late 1960s, Burpee president David Burpee launched an energetic campaign to have marigolds named the national flower, but in the end, roses won out.
  • For years, farmers have included the open-pollinated African marigold ‘Crackerjack’ in chicken feed to make egg yolks a darker yellow.
  • Marigolds are one of the October birth flowers.

Cooking Notes

  • The bright petals of signet marigolds add color and a spicy tang to salads and other summer dishes.
  • The flower petals are sometimes cooked with rice to impart the color (but, unfortunately, not the flavor) of saffron.
  • ‘Mexican Mint’ (sometimes called Texas tarragon) is a sturdy little herb that can be substituted for French tarragon in cooking. This species has been long used in Latin America for tea as well as seasoning.

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Tagetes

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