No one is quite clear why Downton Abbey’s Lady Edith chose the name Marigold for her daughter’s name, but naming baby girls after flowers was common in England during the 1920s. I’d like to believe Marigold was named for both her beauty and resiliency. This spirit is why the marigold nearly became the floral emblem of the U.S.
Alas, the marigold lost to the rose in 1986. Our girl was asked to her prom but never made prom queen.
French marigolds (Tagetes patula) are really native to Mexico. The African marigold (Tagetes erecta) also hails from Mexico. Our marigold is a native of North America and an American in all the ways that count. She’s one of us.
Why should you grow marigolds?
Marigolds look great in planters, hanging baskets, or ornamental beds and borders. Marigolds can also be an excellent addition to the vegetable garden. Many gardeners don’t plan on growing flowers in their vegetable gardens. However, the placing of flowers in with vegetable plants will encourage diversity of plants and wildlife as well as attract pollinators and protect the soil.
Marigolds are also very easy to grow
Marigolds will grow in a wide range of soil types and conditions. All they really demand is plenty of sunlight. They are nearly trouble-free.
Marigolds can be started from seed between four to six weeks before the last frost date. In Central Virginia, that is about the second or third week in April. They’re also quick to germinate — often within 10 days.
It’s a tad late in the season now to start from seed, but inexpensive bedding plants are still available from many gardening centers.
Marigolds attract predatory insects
They don’t just draw in pollinators, they also attract insects that help in natural pest control. Marigolds entice lacewings, ladybugs, parasitic wasps and other predatory insects that will eat aphids and other pests.
Marigolds make great trap plants
A trap crop is a planting that lures pests to keep them away from other more valuable plants. Slugs generally like marigolds, so planting ‘sacrificial’ marigolds around the edges of a bed might help protect other flowers. For example, slugs will be drawn to the marigolds rather than other plants.
Marigolds repel certain pests
Sorry, marigolds don’t repel deer or rabbits. There is some evidence that marigolds—at least in part—help repel cabbage moths and Mexican bean beetles.
Marigolds produce chemicals that repel nematodes
Nematodes are little organisms, roundworms, which make up the phylum Nematoda. There are many different species of these tiny, thread-like creatures.
Some nematodes cause problems for plants and people. Others do not. Marigolds produce compounds in their roots called nematicides. In all honesty, most gardeners are unable to determine which nematodes we have in our soil.
The bad guys can promote poor root development and swollen root tips in plants. This can appear in a plant that is stunted or exhibits interveinal chlorosis. Interveinal chlorosis is the yellowing of leaf tissue between the leaf veins while the veins themselves remain green.
When certain marigolds are integrated with certain nematodes, the marigolds will kill off the nematodes in that particular spot thus reducing the nematode numbers. This can control a harmful nematode population. Marigolds may also excrete a chemical which can repel nematodes in surrounding areas.
Companion planting with marigolds helps, but the science is not conclusive regarding nematode control. Some attractive bedding plant or French marigold cultivars produce higher levels of toxin and might be considered more effective in reducing bad nematodes in soil. ‘Petite Gold,’ ‘Petite Harmony,’ ‘Tangerine,’ and ‘Goldie,’ ‘Polynemia’ and ‘Single Gold’ are recommended. Leaving roots in the ground at the end of the growing season can help to increase the efficacy of repelling nematodes. Marigolds might help control nematodes, but they will not eliminate them. If you have a severe problem, you may have to consider choosing and growing disease resistant plant varieties or practice other pest control measures in your garden. A call to your Cooperative Extension office is a good starting point for a solution.
Marigolds are a poor man’s saffron
On a happier note, I’ll conclude with marigolds as an edible flower. Their colorful petals have been fed to chickens to promote richer colored egg yolks. Don’t have saffron? Marigold petals can be used to enhance the golden color in soups and stews. The petals can also be used as a natural food coloring for cake frosting and other goodies. Numerous recipes can be found on-line especially for Calendula officinalis often called a marigold.
Virginia McCown is a master gardener living in Central Virginia along with her garden and assorted creatures both great and small.