My first experience with growing calendula from seed was tossing a wildflower mix into one of my front yard gardens. It was fun to see all the different flowers reveal their blooms throughout the growing season. The superstar, though, was the calendula, which produced vibrant, sunny blooms right into December. While a few of the wildflowers have popped up again here and there after reseeding themselves, it’s the daisy-like calendula that dependably returns each year in that one little area. In this article, I’m going to share how easy it is to grow calendula from seed.
Part of the Asteraceae family, calendula (calendula officinalis) is also called pot marigold. Calendula is often included in herb gardens because of its various medicinal and DIY uses. It’s known for its anti-inflammatory benefits and is used to create fabric dyes. The plant is also a no-fuss addition to flower beds and borders because of its attractive foliage and profusion of blooms.
Is calendula an annual or a perennial?
In cooler climates, up to zone 9, calendula is grown as an annual. Because of its resistance to lower temperatures, it’s considered a hardy annual. It may seem like a perennial if plants reappear each year, but that’s because once those seed heads form, they will self sow in the garden.
Why grow calendula?
The main reason to grow calendula from seed is because it’s very easy. Sow calendula seeds to fill in spaces in a perennial garden or as part of your annual planting. Plants are quick to grow, taking about six to eight weeks to reach maturity. Because of calendula’s thick foliage, plants are good at keeping weeds at bay. And I love when I can harvest something from the garden either for a project or my plate.
Calendula flowers attract pollinators to the garden, like bees and butterflies, as well as other beneficial insects.
In her book, Plant Partners, Jessica recommends growing calendula to deter aphids from feasting on your cole crops. These include collards, cabbage, broccoli, Brussels sprouts, and cauliflower. Not only does calendula deter these little pests from infesting your veggies, they attract a variety of beneficial insects that feed on them!
Direct-sowing calendula seeds
Calendula is not one of those plants that is necessary to give a head start indoors (though you certainly can if you have the space, see below). There are three easy ways to grow calendula from seed right in the garden. You can start seeds by winter sowing. The second way is to simply allow the blooms to dry out at the end of the growing season and fall into the garden where the seeds will self sow. Or, direct sow calendula seeds after the last spring frost has past.
Choose an area that gets full sun to partial shade with well-drained soil. Amend the area with a bit of compost to add nutrients to the soil. Scatter seed about every six inches (15 cm) and lightly cover seeds with about a quarter to half an inch (½ to 1 cm) of soil. Or, gently push them into the soil to that approximate depth. Water lightly. You can also consider sowing seeds a few weeks apart to stagger blooms. Thin young plants, if necessary (move the ones you pull to other parts of the garden).
Starting calendula from seed indoors
Indoors, because germination is quick, you only have to wait until about three to four weeks before your last frost date before starting seeds in seedling trays in a soilless seed-starting mix. Be sure to harden off calendula seedlings before you transplant them to their spot in the garden or to a container. If planting in the latter, make sure your pot has good drainage.
Caring for calendula plants
Calendula are pretty low-maintenance, but deadheading will encourage more calendula blooms throughout the growing season. Simply use your finger to snap off spent blooms at the base of the bud. If you want seeds, be mindful of not deadheading too close to the winter. If your plant doesn’t have a chance to rebloom, you won’t get any seeds. Drought can also encourage premature seed production, so if conditions are especially dry, be sure to give them a bit of water. Too much moisture during a wet summer can lead to powdery mildew.
Calendula can become a bit stunted in super hot weather. But it thrives in the cooler months of spring and fall. If a plant stalls in the summer, be sure to keep it consistently watered and it should bounce back in the fall. I’ve had calendula plants last through a few frosts before finally being taken out by the first snowstorm of the season.
Calendula isn’t really one of those plants you need to fertilize—too much nitrogen can divert attention to leaf production. But, I always amend the soil with compost before planting. And if you’re giving other annuals a little organic fertilizer boost mid-season, you can include some around the base of your calendula plants.
Collecting calendula seeds
It’s very easy to collect calendula seeds. Once the seed heads have dried on the flower, if they’re ready, they’ll fall into your hand when you touch them.
This video shows you how to collect your calendula seeds and dry them for storage.
If you are growing more than one variety of calendula, it is likely they will cross pollinate. I get a few color variations in the blooms of the calendula plants that grow in my garden. Some calendula have orange flowers, while others are more golden to a pale, yellowy-white!
Growing other annuals from seed