How to Grow Calendula From Seed

Calendula is a cool-season annual that is happiest in mild weather, so timing makes all the difference. Direct-sow the seeds outdoors a couple of weeks before your last spring frost, since young plants shrug off light frost, or start them indoors 6 to 8 weeks earlier for a head start. In hot-summer regions it also makes a wonderful fall and winter flower. For blooms from early summer until frost, sow a fresh short row every 2 to 3 weeks.

Sow calendula seeds about a quarter inch deep and cover them well, because unlike many flowers these seeds need darkness to germinate. Firm the soil, keep it evenly moist, and seedlings usually appear in 7 to 14 days at around 60 to 70F. Grow in full sun to light shade in average, well-drained soil; calendula is not fussy and even does well in a large pot. Thin or transplant the seedlings to about 8 to 12 inches apart so air can move freely between the plants.

Calendula is one of the easiest flowers you can grow. Water when the top inch of soil dries, and skip heavy feeding, since rich soil gives leaves at the expense of flowers. The single most useful habit is deadheading: pinch or snip off faded blooms every few days and the plant will keep pumping out new flowers right up to a hard frost. In hot regions like Texas, Florida, and the Deep South, calendula slows and stops blooming once highs stay in the 80s and 90s, so grow it as a fall-through-spring flower there, while gardeners in the North and Pacific Northwest enjoy it all summer.

Calendula is a classic companion flower. It draws in hoverflies, ladybugs, and bees that hunt aphids, and its sticky stems are often used as a trap crop to lure pests away from vegetables. These four make especially good companions, and you can add any of them in one click:

Pick calendula flowers in the morning once the dew has dried and the blooms are fully open, snipping them right at the base of the flower head. Harvesting often actually encourages more flowers, so cut freely. To dry them, spread whole heads or loose petals in a single layer somewhere warm and airy out of direct sun until they are papery and crisp, then store them in an airtight jar away from light. The bright petals keep their color well for months.

Calendula petals are edible and have a mild, slightly peppery, faintly tangy flavor. Scatter the fresh petals over salads, soups, rice, and butter for a splash of gold, or dry them to stir into baked goods and a pretty herbal tea. Cooks have long called calendula the poor man's saffron, since the dried petals lend food a warm yellow color. Beyond the kitchen, the flowers are a favorite of pollinators and make cheerful, long-lasting cut flowers for the table.

• Few flowers: usually too little sun or too much nitrogen. Give calendula full sun, go easy on feeding, and deadhead often to keep blooms coming.
• Powdery mildew: a white dusty coating in humid, crowded conditions. Thin plants for airflow and water at the base, not overhead.
• Aphids: calendula sometimes acts as a magnet for them, which can actually protect nearby crops. Rinse heavy clusters off with water and let ladybugs and hoverflies do the rest.
• Plants fizzle in summer heat: calendula dislikes high heat. In hot climates grow it in the cool of fall, winter, and spring.