Growing Calendula From Seed – Planting Guide

Growing Calendula from Seed

Hello friends, we are here with a new topic called “growing Calendula from seed”. The scientific name of Calendula is Calendula officinalis and it is a member of the Asteraceae family. Calendula is also called Pot Marigold, English Marigold, or Poet’s Marigold is an Annual Flower. It is an annual plant and it self-seeds easily so the plant will grow on its once in the next season and it can survive the winter season in mild climates. Calendula is planted as a companion plant to many plants like tomatoes and potatoes to help deter insect pests and can be easily grown in the comfort of your home.

The lovely colorful flowers of this Calendula plant add a splash of bright color to the garden. Its edible flowers are mainly used to a distinct flavor to salads and other dishes. It is highly tolerant to cold weather and has been used as a container herb for a very long time. It can flower from spring right through summer and autumn season until plants get halted by frost in the winter season. It grows up to knee height depending on soil and variety. Also, it is easy to grow from seed and blooms long without the need to deadhead.

A Quick Guide to Planting for Growing Calendula From Seed

Planting for Growing Calendula From Seed
Planting for Growing Calendula From Seed (Image source: pixabay)
  • Botanical name – Calendula officinalis
  • Family name – Asteraceae
  • Common Name – Calendula, pot marigold, and common marigold
  • Mature Size – About 1 to 2 feet tall and wide
  • Soil Type – Average and well-drained soil rich in organic material
  • Soil pH – Neutral (6.0 to 7.0)
  • Sunlight – Full sun to partial shade
  • Maturity – About 45-60 days from seed to flower
  • Height – 18 to 24 inches
  • Spacing – About 24 to 36 inches apart in all directions
  • Germination temperature – 22°C, Growth temperature – 24°C
  • Best Companions – Cucumber, Tomato, Peas, Carrot, Asparagus, Radish, Parsley, and Thyme, etc.
  • Worst Companions – Sage, potato
  • Watering – Water the Calendula plants during dry periods, once or twice per week
  • Bloom Time – May to early fall season; will rebloom constantly if old blooms are dead-headed
  • Flower Color – Yellow, orange, cream, pink
  • Hardiness Zones – Perennial in zones 9 to 11 (USDA)
  • Toxicity – Non-toxic
  • Have bright, sassy orange and yellow flowers 2.5-4 inches across on plants 18-24 inches tall
  • Easy to grow indoors (start 6-8 weeks before the last frost) or sow seeds outdoors after the last frost
  • It requires full sun and compost-rich soil or potting soil
  • Like marigolds, Calendula also will help repel insects, so are great for companion planting

Varieties of Calendula

There are several varieties and Calendula cultivars, offering flowers of slightly different appearances. Some popular Calendulas include;

‘Touch of Red’ – It has dark red underneath and on the edges of each petal. Flowers feature red-tipped petals with shades of yellow and orange color.

‘Triangle Flashback’ – It has soft and apricot-pink color flowers.

‘Radio extra’ – It is a tall variety with bright orange, cactus-like blooms

‘Pink Surprise’ – It has ruffled gold and yellow color flowers

‘Touch of Red’ – Flowers with a mixture of orange and red color shades with red-tipped petals

‘Neon’ – Double-petaled flowers in bold colors

‘Greenheart Orange’ – Flowers with orange color petals surrounding lime-green centers.

‘Tangerine Cream’ – Double-petaled flowers with bi-color blooms of bright orange and cream

‘Bronzed Beauty’ – Cream and peach flowers that grow on tall stems

‘Citrus Cocktail’ – A compact, short plant with yellow and orange flowers; works well in containers

‘Sherbet Fizz’ – It has buff-colored flowers with deep red undersides petal tips

‘Dwarf Gem’ – A compact variety with double-petal blooms of orange, yellow color flowers

‘Fruit Twist’ – It has a mix of single, double, and semi-double flowers in yellow and orange color flowers

‘Art Shades’ Mix – Flowers have bright variations of yellow and orange, in single color or bicolor. They tolerate poor sites well.

‘Bonbon’ Series – It has extremely dense, pompom-like flowers, grow in shades of yellow and orange color. Look good in containers. Buy beautiful pots online.

‘Calypso’ Series – It has compact, dense plants great for container growing. Flowers have dark-colored centers and feature shades of orange and yellow color.

Difference between Marigolds and Calendulas

Are marigold and Calendula the same? The simple answer is No. Both plants are members of the sunflower or Asteraceae family. Usually, Marigold plants are members of the Tagetes genus includes at least 50 species while the Calendula plant is a smaller genus with 15 to 20 species.

Seeds – Calendula seeds are brown in color, curved, and slightly bumpy. Marigold seeds are straight black color seeds with white color, paintbrush-like tips.

Shape – Generally, Calendula petals are long and straight, and they can be orange, yellow, pink, or white. Marigold petals are more rectangular with rounded corners. They aren’t flat, but slightly wavy. Flower colors range from orange to yellow, red, mahogany, or cream.

Site Preparation for Growing Calendula from Seed

Generally, Calendula plants mostly prefer full sun but will tolerate light shade in warmer regions. It is best planted in prepared garden beds or large containers filled with organic potting soil. Before planting, use a shovelful or two of well-aged manure or compost into the ground to improve soil conditions.

Soil and Light Requirements for Growing Calendula from Seed

Calendula requires full sun or part shade. Calendula will not do well in the hot summer heat and prefers the cooler temperatures of the spring season and early fall season. Water the Calendula plants regularly until well established. Calendula is tolerant of ordinary soil, yet prefers optimal conditions that offer rich and nutritious organic soil. It does well naturalize in meadows and herb gardens, as well as in the flower border.

Sowing Calendula Seeds                                      

Calendula grows in most soil types and will even tolerate partial shade. The plants do best in sunny positions though, especially on well-drained soil. Sow the seahorse-like seeds in the autumn or spring season. Sowing them in autumn will give the Calendula plants a head-start and you’ll see flowers much earlier. Calendula seeds germinate best at between 15-25°C. Though, sow about 6 to 8 weeks before the first frost in modules filled about 1-part perlite mixed with 3 parts multi-purpose compost. Then, top dress with horticultural grit waters it in and keeps moist undercover in a bright place. The seeds must be sown 1.25cm (1/2”) deep.

You’ll see leaves emerge 6 to 15 days after sowing. With protection from both the cold and slugs the plants will overwinter well and you can plant them outside after the last frost in the spring season. If growing in a tray, you’ll probably want to plant them individually in modules before the winter season.

You can sow Calendula seeds in modules in the spring season. Use the same instructions above and sow 6 to 8 weeks before the last frost date if you’re starting them off inside or in a heated greenhouse. If your greenhouse is unheated, sow seeds after the last average frost date.

Growing Calendula Flowers in Pots

  • Calendula flowers can be easily grown in pots or containers. Feel free to decorate the balcony, kitchen, and other office spaces with Calendula flower pots as long as the spot receives enough sunlight.
  • Use well-draining, organic potting soil or also make your mixture with half garden soil and half well-rotted compost for Calendula plant growth. The key is to select a container with plenty of drainage holes, as Calendula in containers cannot withstand soggy feet. Container-grown Calendulas plants also need full sun and average nutrients.
  • Take a pot or containers containing plenty of drainage holes to avoid soggy feet.
  • Calendula prefers sunshine it can grow in partial shade. So, place the pot in a spot receiving 6 to 8 hours of sunlight.
  • Calendula plant prefers loose and rich soil with a pH level of 6 to 7.
  • Calendula plant needs plenty of water. Water the pots regularly and mulch the soil. Avoid overwatering, but supply about 1 to 11⁄2 inches of water per week for optimal plant growth.
  • Gather Calendula flowers late in the morning. They are fully open and then the dew has dried. Pick the complete flower at full bloom. Flowers will re-bloom in about 2 weeks. Also, you can collect seeds when fully mature and dry.

Caring for Container Grown Calendula

Calendula plant care in a container couldn’t be easier and keep the soil moderately moist. Generally, the plants do not need fertilizing, but a high phosphorus formula can encourage more blooms. Calendula plants don’t need deadheading, as their seed heads are quite ornamental. Pull off the Calendula seeds and save them in an envelope in a dark and dry location until the next season.

Use a natural product to ward off slugs and snails, which seem to find Calendula as tasty as we do. For minimizing pests like aphids, whiteflies, and cabbage loopers apply insecticidal soap sprays every few days. Therefore, these natural practices will preserve the flavor and safety of the Calendula flowers.

Process of Growing Calendula from Seeds Indoors

It is best to grow Calendula seeds indoors 6 to 8 weeks before the last spring frost in colder climate conditions. Fill about 2-inch peat pots with potting soil, leaving a half-inch of space between the potting soil’s surface and the top of the pot. Sow 2 Calendula seeds in each pot at a depth of about 1/4-inch. Light inhibits Calendula seed germination so be sure the seeds are completely covered with soil. Mist the soil until it feels very moist in the top about 1/2 inch, and then cover the pots by using a sheet of plastic wrap.

Set the peat pots near a large and sunny window with southern exposure. Make sure the location you choose receives at least 6 hours of bright, direct sunlight each day. Watch for the germination process in 10 to 14 days. Remove the weaker of the 2 Calendula seedlings from each pot if both seeds germinate. Then, discard the plastic wrap when the Calendula seeds germinate.

Transplanting Calendula Seedlings – Calendula seedlings are adaptable and establish quickly after transplant but they perform best if slowly acclimated to outdoor conditions, which is a process called hardening off. Slowly expose the seedlings to direct sun and wind after the first week of planting. After 2 weeks, the seedlings can be transplanted into a sunny garden bed with moderately fertile, fast-draining soil or into a large pot with drainage holes at the base.

Transplant Calendula seedlings approximately 16 inches apart to provide enough space for their mature spread. Be sure to plant the Calendula seedlings at the same depth they grew in their pots. Keep the soil moist during the first 2 weeks after transplant, then water whenever the soil feels mostly dry in the top inch.

Tips for Growing Calendula from Seed

In case if you miss this: Growing Eggplants from Seeds.

Tips for Growing Calendula from Seed
Tips for Growing Calendula from Seed (pic credit: pixabay)
  • Calendula plant is easy to grow from seed directly sown in the garden. Whether you start the seeds indoors or outdoors, the Calendula seed germination process is simple.
  • Choose a sunny site. The more sun is the better for growing Calendula.
  • For Calendula plants, the soil needs to be moderate-rich and drain well. It will tolerate poor conditions but perform better when it has nourishing soil. Calendula does not need any extra fertilizing once established.
  • Calendula grows nicely in the vegetable garden. Good companions for Calendula are Cucumbers, Tomatoes, Peas, Carrots, Asparagus, and spring salad vegetables.
  • The Calendula flowers bloom best in cooler weather with low humidity and the Calendula plant needs regular water
  • If the foliage looks haggard, cut Calendula plants back to about 3 inches to promote new growth.
  • During hot weather conditions, give your Calendulas 1 to 1 1/2 inches of water once a week. Although these Calendula plants can tolerate low-water conditions, regular irrigation encourages summer blooms.
  • Pull any weeds growing near Calendula plants. Applying about 2- to 3-inch layer of organic mulch stops weeds while helping maintain consistent soil moisture and cooler soil temperature levels.
  • Remove spent flowers to keep the plant looking tidy and to encourage additional blooms. Calendula self-seeds quickly and sometimes becomes weedy if not deadheaded regularly.
  • Pinch back young Calendula plants to promote a bushier form. Severely cut back Calendula plant starts suffering in the summer heat. This helps keep the plant healthy enough to recover and produce autumn blooms.

Starting Calendula Seeds Outdoors

  • Sow Calendula seeds outdoors during the spring season. Avoid warm temperature levels, as they will produce only weak plants. For optimal fall flowering start the new set of seedlings during the summer season. Note that the Calendula seeds self-sow readily. The plant needs germination temperature from 12 to 15°C.
  • Although Calendula germination temperatures vary until soil temperatures reach 15°C before sowing Calendula seeds directly in the garden. Then, spray the bed to settle the soil around the Calendula seeds. While the Calendula seeds germinate maintain moisture in the top inch of soil. Watch for signs of germination 10 to 14 days after seed sowing. Thin the seedlings to one every 12 inches once they grow to about 2 inches in height. Remove all but the hardiest seedlings.

Watering Requirements for Growing Calendula from Seed

To promote Calendula flowering, stress the plant by reducing water intake after about 4 or 5 weeks. For 3 days, do not water your plant (or water very little if you have rapidly draining soil). After 3 days gradually increase water and you should see blooms after about 3 days.

Fertilizer and Mulching Requirement for Growing Calendula from Seed

A layer of garden compost spread in the garden before sowing Calendula seeds will encourage healthy growth, yet over-fertilizing will produce more leaves than flowers. Supplement mid-season with liquid seaweed or organic fertilizer spread at the plant base.

With fertile garden soil, the Calendula plant requires no additional feeding at all. Marginal soils may need feeding with a balanced water-soluble fertilizer, but over-feeding can make the plants leggy and spindly. Growing Calendula plants in containers require monthly feeding with diluted balanced fertilizer.

Spring mulch by using a layer of natural bark or hay around the plant base, may reduce weeds and keep the soil moist.

Pests and Diseases Management in Growing Calendula Plants

Insects and diseases are not a problem for Calendula plants. The Calendula flower can help deter insect pests, making it a good companion plant for vegetable gardens. One of the most common problems for growing Calendula is a tiny insect that likes the blooms as much as you do. Aphid feeding causes curled leaves and they produce honeydew which attracts ants. Aphids love to feed on the undersides of the plant leaves, if this Calendula problem is severe, treat the plants with insecticidal soap. Whiteflies are small white flies that hide and feed on the undersides of the plant leaves. Just as with aphids, these can be controlled by using a hard stream of water or application of insecticidal soap. Other pests that can cause Calendula issues include snails, slugs, and thrips but they tend to be a very minor threat.

Additional problems with growing Calendula include the fact that these plants may be susceptible to powdery mildew. This fungal disease causes white fungal patches on the plant leaves that easily spread to other plants. It is fostered by cool, wet weather. To manage powdery mildew disease, plant to allow for air circulation, and remove any infected plant parts. Calendula smut disease is another disease that can plague the plants and results in brown spotting. Alternaria leaf spot causes small red or purple color spots to appear. Apply a fungicide and practice good garden sanitation for fungal diseases. Aster yellows, caused by a phytoplasma rather than a bacterium or fungi, are another problem of Calendula. It causes plants to become stunted with yellow-green color leaves and flowers and eventual death. Remove and destroy any infected plants.

You may also check this: Growing Broccoli In Greenhouse.

How to Treat Sick Calendula Plants

To combat diseases in Calendula plants, practice good sanitation, allow sufficient space between plants, and apply fungicides. Crop rotation is also an important part of managing diseased Calendula plants. Then, remove and discard infected plants to slow the spread of the disease. In the case of aster yellows, keep the area around the Calendula plants weed-free and take steps to control them. Also, remove infected plants.

When and How to Harvest Calendula

Some growers find the taste bitter, the flowers and leaves of Calendula can be used in salads and other recipes. Also, Calendula is a medicinal herb that has been used in topical ointments for cuts and scrapes.

Harvest Calendula when fully bloomed, using only the petals for consumption. Carefully collect Calendula flowers in the late morning, after the dew has dried. Pick flowers when they are fully open, and check because they come and go quickly. Though, turn them occasionally until they are papery dry, and then store them in canning jars until ready to use.

Commonly Asked Questions about Growing Calendula from Seed

Does Calendula come back every year?

The Calendula flower is an annual plant that will readily reseed.

Will Calendula grow in shade?

Calendula is best planted in well-drained soil of loam, sand, and chalk within a neutral, acidic, or alkaline pH level balance. The plants are best positioned in an area of full sun or part shade.

How many hours of sun does Calendula need?

Grow Calendula in a spot with full sun means at least 6 to 8 hours of direct sun per day.

Why is my Calendula plant dying?

If Calendula plants die out due to hot summer weather conditions, cut them back hard and water. Then, they will start growing again when cooler weather returns. Plants can self-sow, so allow some to set seeds and remove plants after they are killed by heavy frost in the fall to avoid disease issues the following year.

How long does it take for Calendula to grow?

Calendula plants are easy to grow from seed and quickly grow to maturity in 6-8 weeks after sowing.


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