The Best Time to Sow Calendula Seeds for Maximum Blooms

Calendula, also known as pot marigold, is a wonderfully easy annual flower to grow from seed. With its sunny yellow and orange blossoms, it brings cheer to any garden Calendula also has a long blooming season, especially if you stagger your sowing. So when is the optimal time to sow calendula seeds? Read on to learn the best techniques for starting these bright beauties at just the right time

An Overview of Calendula

Before diving into precisely when and how to sow them, let’s first take a quick look at calendula itself.

• Calendula officinalis is an herbaceous annual or short-lived perennial, depending on your climate zone.
• It thrives in sunny spots and average soil as long as it drains well.
• The daisy-like flowers come in shades of yellow, orange, peach, apricot, cream, and red.
• Blooms are edible and used in salads or to color butters and cheeses.
• The dried petals and flowers have anti-inflammatory, antifungal, and antioxidant properties.
• Calendula attracts pollinators and beneficial insects to gardens.

With proper sowing, this cheery flower will give you months of color and harvesting potential in flower beds, borders containers and vegetable gardens.

When to Sow Calendula Seeds Outdoors

Calendula thrives when directly sown right in the garden. Here are the optimal times and techniques for outdoor sowing.

Early Spring

The first opportunity to sow calendula seeds is in early spring as soon as the soil can be worked. Calendula will tolerate some light frosts, so you get a jump start on the season by starting seeds a few weeks before your last expected spring frost date.

Target sowing for 6-8 weeks before your average last frost to give seeds time to germinate and grow to a mature size that can handle a frost.

Spring

You can continue sowing calendula seeds every 2-3 weeks in spring up until early summer. This ensures a prolonged harvest and blooming period.

Staggering sowing gives young plants time to establish without having to compete for light and nutrients. It also prevents having blooms fade all at once, allowing you to have fresh flowers for months on end.

Early Fall

In areas with longer growing seasons, sow a late crop of calendula in early fall about 8-10 weeks before the first expected autumn frost.

This will provide bright blossoms in the cooler weather when many other annuals have finished up for the season. Plus, the late sowing establishes plants that will self sow for earliest blooms the following spring.

Winter Sowing

If you live in an area with cold winters, try winter sowing calendula seeds. This technique allows you to sow seeds in mini greenhouses outdoors during winter so they germinate as soon as spring warmth arrives.

Recycle plastic containers, line them with plastic wrap, add potting mix, sow seeds, and seal the greenhouse up tight. Place them outside in a sunny spot and let nature take its course. The greenhouse protects seeds from harsh elements while allowing the natural freeze/thaw cycle to gently break dormancy.

When to Start Calendula Indoors

While calendula grows well directly sown, you can also get a head start by sowing indoors.

Late Winter

The optimal window is 8-10 weeks before your frost free date when outdoor sowing is still too chilly.

Start seeds indoors during late winter so plants are ready for transplanting once outdoor temperatures are steadily above 50°F. Avoid sowing too early and having leggy seedlings.

Early Spring

You can also sow seeds indoors approximately 3-4 weeks before your last expected spring frost. This shorter lead time works well if you get a late start or have limited space under lights.

Summer for Fall

Indoor sowing in summer can provide transplants for a fall crop. Sow seeds 8-10 weeks prior to your first autumn frost so calendula has time to mature and bloom before freezing weather finishes the season.

How to Sow Calendula Seeds Outdoors

Sowing calendula directly in the garden is easy. Follow these simple steps for success.

Choose a Sunny Spot

Select a location that will provide full sun to partial shade. Areas near walls or fences make nice microclimates if your garden lacks sheltered sunny spots.

Prepare Soil

Give seeds the best start by preparing soil in advance. Loosen and mix in 1-2 inches of aged compost or well-rotted manure a few weeks before sowing. This provides nutrition and helps retention moisture.

Sow Seeds

Once soil is workable in spring, sow seeds approximately 1/4-1/2 inch deep and 6 inches apart. Gently water to settle seeds into soil contact.

Maintain Moisture

Keep seeds and seedlings consistently moist but not saturated until plants become established. A light mulch can help conserve moisture.

Thin or Transplant

If seeds are too close once germinated, carefully thin or transplant seedlings at least 12 inches apart to allow for growth and air circulation.

How to Sow Seeds Indoors

You can also get a head start on the season by sowing indoors. Here’s how.

Use Seed Starting Mix

Fill seedling trays or cells with a quality seed starting mix that is loose, nutrient-rich, and designed to prevent fungal disease.

Sow Seeds

Sow 2-3 seeds per cell. Gently press into the soil surface but don’t bury too deeply.

Maintain Warmth

Keep newly sown pots at 70-75°F until sprouting, whether on a seedling heat mat or near other heat sources.

Provide Light

Once sprouted, move to bright light. Supplement with grow lights to keep plants from stretching toward windows.

Transplant Outside

Harden off plants for 7-10 days before transplanting into the garden after the danger of frost has passed.

Acclimate Plants

Set transplants in dappled shade for a few days so they can adjust to outdoor conditions before exposing them to full sun.

Caring for Calendula Plants

Give your calendula patch some simple care and it will reward you with months of blooms.

Water Regularly

Water whenever top inch of soil is dry. Drought can cause flowers to fade and go to seed prematurely.

Deadhead Spent Blooms

Pinch off faded flowers just below the flower heads to encourage more buds to form.

Provide Occasional Fertilizer

Use a balanced liquid fertilizer or compost tea a few times during peak growing season to support flowering.

Watch for Powdery Mildew

Powdery mildew can be an issue in damp conditions. Improve airflow and avoid wetting foliage when watering.

Saving Calendula Seeds

Let a few spent flower heads ripen on plants in fall until nice and dry. Collect seeds to sow again next year.

Growing Gorgeous Calendula Flowers

With the right sowing schedule, you can enjoy calendula’s cheery blooms for months on end. Start seeds indoors or out based on your climate and the season. Stagger sowings throughout spring and again in fall. Take advantage of calendula’s hardiness and start seeds early for extended color. Then care for plants properly and watch them thrive. Soon you’ll have plenty of bright blossoms and harvested seeds to carry you through until next year’s sowing season rolls around again.