How to Grow Marigolds

Orange and Yellow Marigold
Marigolds ©Nannette Richford

The Legend of the Marigold

According to legend, the marigold earned its name from early Christians who planted this bright flower around a statue of Mary as a substitute for an offering of coins. They are also said to represent the golden rays of glory often depicted around Mary's head. The marigold is often used in festivals honoring the Virgin Mary.
Marigolds bloom profusely from early summer until frost, creating mounds of color in shades of yellow, orange and fiery reds. Many gardeners grow marigolds with tomatoes to repel harmful insects. Although research doesn't support the practice other than for repelling nematodes (microscopic insects in the soil that harm the roots of tomato plants) many home gardeners attest to the effectiveness of marigolds in keeping insects at bay. The scent of marigolds may mask the scent of garden plants and confuse insect pests. Try planting marigolds around the perimeter of the vegetable garden to keep insects away.


Marigolds range in size from tiny dwarf varieties that form dense mounds of 6- to 8-inches in height to gigantic 3- to 4-foot varieties. Dwarf marigolds make excellent bedding plants and can be used for borders or added to mixed plantings in containers. Plant tall varieties at the backs of beds or along fences for a showy display of color. Marigold blooms range from single petals that resemble a cosmos to double blooms like the ones above. 

Buying Marigold Seedlings

Marigold seedlings can be purchased in flats at your local nursery in late spring for a few dollars.  When purchasing flats of marigolds, check the plant identification marker closely for predicted size, bloom type and color. Many are labeled as mixed and produce an assortment of yellow, orange and variegated blooms.

Look for healthy green foliage with short sturdy stems. Tall spindly plants are a sign of inadequate light. Soil should be moist and dark brown to black. Tinges of green or gray on the soil indicate excessive moisture.
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Single petaled marigolds.

Starting Marigolds from Seed

Marigolds germinate quickly and grow rapidly. They can be direct seeded in the garden, but they will bloom later than seedlings from the nursery. If you decide  to start marigolds from seed, try planting them inside 8 to 10 weeks before the last expected frost in your area.
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Dwarf French marigolds are often planted in the vegetable garden to repel insects.
 
  1. Fill plant cells or seed starting trays with moist seed starter. I find that mixing the seed starter with a little water in large bowl to moisten it before filling trays or pots makes it much easier to work with. Dry seed starter does not absorb moisture well and makes watering the seeds difficult.
  2. Plant your marigold seeds to a depth of ¼ inch and cover them with soil. Water them well to moisten the seeds. Cover the seed tray or flat with clear plastic wrap and place it in a warm location to germinate the seeds. The top of the water heater or other appliance that provides gentle, bottom heat works well.
  3. Keep the soil moist, but avoid soggy soil. It the soil becomes soaked, or shows signs of mold, partially open the plastic to allow moisture to escape and air to circulate.
  4. Remove the plastic once seedlings emerge and move them to an area with bright, indirect light. Although marigolds thrive in full sun, seedlings sunburn easily on a sunny windowsill. Gradually expose them to more sun each day.

Planting Marigold Seedlings

Prepare the soil in a sunny location that receives 6 to 8 hours of direct sunlight a day. Marigolds will grow in less light, but do not perform as well. 

Plant the marigold seedlings to the original planting depth spaced to the recommended spacing for your variety. Dwarf varieties can be spaced 6 to 8 inches apart, while tall varieties require 12 inches or more between plants. Fill in around the roots with soil. Firm the soil down with your hands to secure the plant and to remove air pockets in the soil. Water the seedlings thoroughly to moisten the soil to the root level.
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Marigolds attract beneficial insects, like bees, to the garden.

Marigold Care

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Marigolds add brilliant color to the garden bed.
Water your marigolds deeply once or twice a week to saturate the soil to the root level. Container plants require more frequent watering; some may require daily watering depending on the size of the container, their rate of growth and the weather conditions.

Fertilize marigolds with water-soluble fertilizer designed for flowering plants once or twice a month from spring until fall.

Deadhead spent blooms to encourage the plant to produce more flowers. Removing the old flowers tricks the plant into thinking it has not produced enough blooms to set seed and reproduce. With regular deadheading marigolds continue to bloom until frost.