How to Plant, Grow, and Care for Calendula
Are you thinking of adding calendula to your garden this season? This popular herb has many different uses and is quite easy to grow. In this article, gardening expert and former organic farmer Logan Hailey shares everything you need to know about growing calendula in your garden, including maintenance and care needs.
With its fragrant, resinous flowers and joyful orange blooms, calendula is a delight in the garden. This fast-growing, laidback herb is so easy to grow that one planting may bring flowers and seeds for years to come. It is an eager annual that self-seeds without becoming invasive or overtaking other plants in your garden.
Calendula is one of the most beautiful and functional flowers you can grow. It magnetizes pollinators, attracts beneficial biocontrol insects, and has plenty of other uses in the garden.
With consistent moisture and regular deadheading, calendula will share its happy blooms all summer long. Let’s dig into everything you need to know about growing a vibrant calendula patch!
Plant Type Annual Flowering Herb
Plant Genus Calendula
Plant Species officinalis
Hardiness Zone 3-11
Planting Season Spring
Plant Maintenance Low
Plant Height 10-12 inches
Temperature 50-75°F, tolerates down to 25°F
Companion Plants Most Vegetables and Herbs
Soil Type Well-drained loam, neutral pH
Plant Spacing 6-12 inches
Watering Needs Low
Sun Exposure Full Sun to Partial Shade
Pests Blister Beetles, Flea Beetles, Aphids
Diseases Calendula Smut, Powdery Mildew
Calendula is an annual flowering herb with a medium bushy habit and highly resinous blooms. It is a member of the Asteraceae (daisy) family and has distinctive ray florets that form each petal. Calendula is a very popular cut flower and companion plant for vegetable gardens.
Though it’s commonly called “pot marigold,” it is not actually a marigold. Calendula comes from the Calendula genus whereas marigolds come from the Tagetes genus. Both are members of the Asteraceae or Compositae (daisy family).
History and Cultivation
Calendula is one of the oldest known cultivated flowers in the world. With more than six centuries of domestication, the plant is delightful to grow in almost any garden in growing zones 3-11.
This “Poor Man’s Saffron” has been used in culinary traditions throughout Europe and Asia for thousands of years. The Latin name kalendae translates to “little calendar” or “little clock,” which refers to the plant’s tendency to bloom at the beginning of every month.
This popular low-maintenance annual flower has its roots as a European wildflower but has been widely adapted to the United States. Calendula is also native to Southwestern Asia, the Mediterranean, and the Canary Islands.
Calendula is an eager self-sowing flower that sometimes escapes gardens into nearby pastures and wild areas, however, it is not invasive and will not overtake native plants.
There are about 20 species of small bushy annuals that belong to the Calendula genus. Most garden varieties are Calendula officinalis L. Modern breeders have crossed unique calendula plants to develop dazzling rainbows of floral shapes and colors, including varieties like ‘Pacific Beauty,’ ‘Porcupine,’ and ‘Triangle Flashback.’
All of these varieties are grown similarly and may cross-pollinate to yield floral discoveries that are unique to your garden.
This flower is extremely easy to grow from seed. Most gardeners direct sow it in the spring after the last frost date. You can also start the plants indoors up to six weeks before the last frost date and transplant them outside when the weather has warmed.
One of the coolest things about calendula is its seed shape. These seeds are very fun to examine and plant with children. They may compare the seeds to little “C”-shaped worms, curled snakes, or ancient shells. Thanks to the size of the seeds, they are fairly easy to handle and singulate during planting.
Once you plant calendula, you may not need to do so again! It naturally self-sows by dropping its seeds from withered flowers to keep proliferating the patch.
Once the risk of spring frost has passed, calendula can be seeded in the garden. Start by preparing a weed-free bed with well-drained soil. If your soil is heavy or high in clay content, amend it with compost and aerate it with a broad fork. Make sure the bed receives full sunlight.
Use the back of a garden tool or your finger to create a furrow about ½” to ¾” deep. Plant one of the unique “C”-shaped seeds every 4-6 inches and gently press them into the soil to prevent it from rising to the surface when watered.
Cover with a thin layer of soil or compost. The seeds should end up at a depth of roughly ¼” to ½”, or about two times the depth of their largest dimension.
Thoroughly water in until the soil is moist but not soggy. Keep the soil consistently moist to help with germination, which should take 1-2 weeks.
If the nights are still cool, you can optionally cover it with row fabric to provide extra warmth during germination. Once germinated, thin calendula to 6-12 inch spacing between each plant.
If you feel doubtful about your calendula planting, sow extra seeds and thin them later. These seeds are very forgiving. You can also broadcast seed calendula by sprinkling the seeds over a broad area and distributing a thin layer of soil over the top.
Make 2-3 sowing successions every few weeks throughout the spring for a continuous supply of blooms throughout the summer. Alternatively, just leave a few calendula flowers to go to seed and drop their seeds in place for a new round of plants.
For extra early blooms, you can start calendula seeds in cell trays or pots. The seedlings need to have a warm greenhouse, bright windowsill, or grow lights to help them mature before the weather has warmed outside.
It is best to start calendula seeds indoors 4-6 weeks before the expected last frost date. Fill 6-packs or 50-cell trays with a well-drained seed starter mix. Be careful not to shove the mix into the cell, otherwise, you can cause compaction.
Use a pencil or your fingertip to create a “dibble” about ½” deep in the center of each cell. Then place 1 to 2 calendula seeds in each hole. Cover the seed(s) with a thin layer of seedling soil mix and gently press down to ensure the seed is fully tucked into place.
Give the trays a generous watering with a fan-spray hose nozzle. Avoid blasting the soil with water that may uncover the seeds.
Place the seeded trays in a warm, bright area that is about 70°F. Make sure to keep the soil consistently moist. Germination should occur in about 7-14 days. Once true leaves appear, thin the seedlings down to one plant per cell by snipping away the weaker seedling at the base.
When the chance of frost has passed and the seedling roots have filled out their container, use the steps below to transplant calendula into your garden.
The best time to plant calendula is in the spring after all chances of frost have passed. While established plants can handle mild frosts, young seedlings are more likely to die in harsh weather. Before planting calendula, ensure you’ve prepared a site with well-drained, loamy soil with full sun to partial shade.
As long as you get the timing right, transplanting calendula is a breeze. Seeds can be started indoors any time in the spring, but the ideal window is about one month before your last frost date. Once the seedlings have grown about 4-6 inches tall and fully developed their root system, transplant them using the same method used with vegetables.
Begin by preparing the planting bed. Weed and amend the soil as needed. Then use a hori hori knife or a small trowel to dig a hole that is about twice the size of the root ball. Make sure that the seedling soil is moderately moist but not wet.
Carefully massage the outside of the container to loosen the roots. Grasp the plant from its base and gently pull it out. Gently place the seedling in the hole and then backfill. Keep the soil level even with the base of the plant and avoid burying the stem.
Estimate 6-12 inches of spacing between each plant in each direction. For bulk plantings, stagger the rows to give each plant more space to grow.
Give the newly transplanted seedlings a generous dose of water to help the roots take to their new home. If your soil is rich in organic matter, no fertilizer is necessary. Otherwise, add some compost to the soil.
Calendula typically begins to flower about 50 days after seeding!
How to Grow Calendula
If gardeners in the 1400s (more than six centuries ago!) were cultivating calendula, you should have no problem growing this beautiful flower using modern methods. Calendula is remarkably easy to grow and requires little to no maintenance.
Like most Asteraceae (daisy) family members, calendula prefers full sunshine but will enjoy some partial shade in the heat. These vibrant blossoms don’t like to be too shaded out by their neighbors, so they are best planted in an area with other plants of a similar height, such as in the margins of a garden vegetable bed. If you plant it in too much shade, you may be disappointed by the floral display.
In hot climates, summer flowers can be sensitive to heat stress. Midday shade may help them survive regular scorching temperatures above 85°F. But you still need to be sure that the plants are getting enough sunlight to fuel their needs. Bursting out new flowers every week requires a lot of energy!
Calendula plants typically need 1 to 1.5 inches of water weekly to thrive. In areas with summer rainfalls or rich soil (which holds onto moisture), even less water is needed.
If you are planting as a vegetable companion plant, it will get plenty of residual water from your irrigation system. Alternatively, you can give your calendula border bed a dose of water from the hose once a week in cool weather or every few days in hot weather.
Well-drained, loamy soil is ideal for calendula. This wildflower is quite robust in poorer soils, but it does not tolerate soggy or waterlogged roots.
If your garden has heavy clay soil, consider amending it with compost and broad forking to add aeration to the root zone. The roots can rot if they are sitting in super wet soil.
The ideal pH is 6-7.0 or slightly acidic to neutral. However, calendula can survive in a wide range of soil types.
Climate and Temperature
This vibrant herb is readily adaptable to almost any garden in the United States. It tolerates temperatures down to 26°F but can be heat sensitive in temperatures above 85°F. The plants don’t usually die in extreme cold or heat, but they may stop blooming. Hard freezes will kill calendula plants and leave behind their seeds for next year’s self-sown patch.
For maximum floral display, calendula prefers the cool to moderate weather of spring and early summer. The ideal temperature range for flowering is between 60-80°F.
In zones 3-5, you may need to start them indoors to maximize your bloom time during the brief frost-free months. In zone 6 and warmer, it will reliably bloom for at least 3-4 months of the summer. Calendula can even grow in partial shade as a perennial in hardiness zones 9-11.
Calendula requires little to no fertility to thrive. After all, this plant is used to growing wild in the poor soils of the Mediterranean basin!
If you are planting it in your vegetable beds, the flower should have no problem subsisting from residual nutrients from organic fertilizers and compost. However, if you are growing in extremely poor soil, it is recommended to offer a little dose of compost or all-purpose organic (slow-release) fertilizer.
Avoid planting calendula in areas with excess nitrogen or synthetic fertilizer. Like many flowers, too much quick-release nitrogen can cause calendula to funnel its energy into herbaceous leaf growth rather than blooms. It can also cause infestations of aphids and mites.
The only maintenance calendula requires is floral harvest and deadheading. If you want your plant to keep producing blooms all summer long, it’s best to cut back withered flowers.
This will also help reduce the amount of self-sowing. Seed heads develop fairly quickly and can be collected before they fall into the soil.
There are about 15 species of Calendula, but most seeds are ornamental cultivars of Calendula officinalis. The floral options range from pastel yellow to vibrant orange to variegated and even speckled combinations!
Our favorite calendula varieties include:
- Best for culinary and herbal use: ‘Resina’ calendula
- Best classic variety: ‘Alpha’ calendula
- Best unique flower shape: ‘Zeolights’ calendula (the fluffy bronzy orange petals with a yellow backdrop are dazzling in bouquets)
- Best colorful blend for cut flowers: ‘Flashback Mix’
- Best compact variety: ‘Oopsy Daisy’ calendula
Pests and Diseases
Calendula is renowned for its insectary benefits, but it isn’t immune to these common garden pests. Fortunately, the plants are super resilient and usually bounce back from pest or disease issues within a week or so. Simply yank out any problematic plants and let new flowers grow from their self-sown seeds.
The most annoying and common pest of calendula is a long black beetle called the blister beetle. These beetles frequent a variety of garden flowers, but calendula is one of their favorites.
They are called blister beetles because their bite can cause a mild burn or blister on the skin if they bite you (so wear gloves when dealing with them!)
The beetles are unlikely to kill calendula plants, but they are very unsightly and can make the petals of your calendula blossoms look pretty ragged.
To get rid of Blister Beetles, all you need are gloves and an empty plastic container:
- Put on gloves to protect your hands.
- Fill a plastic container with soapy water.
- Hold the container under the flowers and quickly knock the beetles off into the water.
- Be careful not to touch the beetles with your skin.
In just 5 minutes, you can have dozens of drowned blister beetles and happy calendula flowers!
In serious infestations, you may need to mow down the patch or use a row cover to protect new plantings. Avoid using any pesticides (including organic ones like Spinosad) on calendula because this can hurt the bees and butterflies that are attracted to calendula.
Flea beetles don’t only attack arugula and radishes! These tiny bugs sometimes leave mini shot holes in the leaves.
The easiest way to keep flea beetles out is with a physical barrier like row cover. Once plants are established and forming flower buds, you can remove the row cover and allow nature to take care of the rest.
These sap-suckers seem to go for everything in the garden, huh? While calendula can attract beneficial insects that eat aphids, sometimes these bugs go for the resinous flowers themselves. Calendula is rich in nectar and everyone seems to want a sweet sip.
The best way to keep aphids out of your calendula is to avoid fertilizing the plants. A sudden spike in nitrogen can attract aphids to the leaves and flowers of calendula. If aphids do appear, use a strong blast of water or diluted neem oil to get rid of them.
This ugly fungal disease causes unsightly brown spots on calendula leaves. The rounded lesions can also be greenish-yellow or black. The thick diseased spots are thick and can grow through the leaf from front to back.
The easiest means of prevention is simply watering the plants from the base rather than using sprinklers. You can also rotate calendula around the garden or spray with a diluted neem solution if you are very concerned about the appearance of the foliage.
In warm, humid climates, calendula may get a whitish-gray coating like someone spilled flour on it. This fungal disease thrives in moist conditions without much aeration.
You can space calendula wider apart (up to 18”) between plants to encourage airflow. Remove any diseased parts and thoroughly sanitize tools. Never compost mildew-infested leaves or flowers. Avoid overhead watering calendula.
You can use calendula for everything from vibrant salad garnishes to skin-healing oils to cut flower arrangements. With such an easygoing attitude and a plethora of uses, why wouldn’t you plant this joyful flower?
Calendula is one of the most popular companion plants for nearly every vegetable or fruit in the garden. It attracts a range of beneficial predatory insects that help keep pest populations in check, including:
- Hoverflies or Syrphid flies
Calendula is also known to repel:
- Tomato Hornworm
- Asparagus Beetle
Because this is a non-aggressive annual flower, it is perfectly fine to plant it in your garden beds. It works great when interspersed amongst tomato plants or sown in the four corners of a raised vegetable bed.
The nectar-rich, resinous blossoms of calendula are very popular amongst pollinators. Calendula’s pollen can be very beneficial to honeybees. If you are planting a pollinator garden, this low-stress flower is the perfect plant to start with.
Calendula offers a long-lasting floral display as a smaller accent flower in arrangements. The blooms also hold up nicely in dried bouquets.
Frequently Asked Questions
Does calendula come back every year?
Calendula is a self-sowing annual herb. While the same plant will not survive the winter, the seeds dropped from withered flowers reliably sprout the following year. Once you buy calendula seeds, you may not need to plant them ever again!
It readily reseeds itself year after year without becoming invasive. If you don’t want the plant to self-sow, simply deadhead withered flowers before they can form seed heads.
Where does calendula grow best?
Calendula thrives in well-drained soil with full sunshine in zones 3-11. It particularly enjoys the mild, cool weather of spring and fall. It can get a bit heat-stressed in scorching summer climates, but it usually starts flowering again when the weather cools.
What month does calendula bloom?
Calendula usually blooms about 50 days after it is seeded. In most temperate climates, flowers begin appearing in late May. Plants continue to bloom until the first hard frost of autumn.
Before planting calendula, make sure you are ready for a vibrant display! The sunshiney flowers will bring a smile to your face every year. These blooms will also bring a huge range of benefits to your garden and local insects.
As long as you provide it with regular water and ample sunshine, calendula is one of the most lowkey flowers you can grow. Don’t forget to collect some of the “C”-shaped seeds to share with your neighbors!