Calendula in Zone 9B — Gulf Coast

Calendula is a winner in the Gulf Coast garden for so many reasons. The bright, cheerful flowers aren't just pretty; the petals are edible, adding a peppery kick to salads, and they have medicinal properties too. Plus, with our long growing season, you'll get a ton of satisfaction from a plant that blooms almost year-round.

Sure, our high humidity and tendency for afternoon storms can bring challenges, but Calendula is surprisingly resilient. With some smart timing and attention, you can enjoy these beauties throughout our 319-day growing season, even during the warmer months.

Starting Calendula indoors is an option, particularly if you want a head start on blooms. Start your seeds indoors from late November through mid December, about six weeks before you plan to transplant. Use seed trays and keep them in a warm spot with plenty of light – a sunny windowsill or under grow lights works well.

When you water, try bottom watering to avoid damping off, which can be a problem with our early spring humidity. Just set the tray in a shallow dish of water and let the soil soak it up from the bottom. This is especially useful in our region, since our springs can come early with a warm spell.

Transplant your Calendula seedlings outdoors from mid January through late February. Before you do, harden them off by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the real world – think sun, wind, and fluctuating temperatures.

Plant them 8-12 inches apart in well-draining soil. Keep an eye on the weather forecast; we can still get some cool snaps during this time, and while Calendula is hardy, young seedlings appreciate a little protection if a freeze is predicted.

Direct sowing Calendula is super easy and works well in our Gulf Coast climate. Sow seeds directly into the garden from mid January through mid October. Choose a spot with full sun to part shade, and make sure the soil is loose and well-draining.

Gently press the seeds into the soil, about ¼ inch deep, and keep them consistently moist until they germinate. Thin the seedlings to 8-12 inches apart once they're a few inches tall. Direct sowing is a great option because it avoids transplant shock, and the plants often catch up quickly.

Calendula needs moderate watering, but it's not a fan of soggy feet, especially with our high humidity. During the cooler months (late fall through early spring), you probably only need to water once or twice a week, depending on rainfall. Let the top two inches of soil dry out between waterings – use the "finger test" to check.

In the hotter, more humid summer months, you might need to water every other day, or even daily if it's been dry. Aim for about an inch of water per week, either from rainfall or irrigation. Water at the base of the plant to avoid wetting the foliage, which can encourage fungal diseases in our humid environment.

Wilting leaves indicate underwatering, while yellowing leaves can signal overwatering. Add a layer of mulch around your Calendula plants to help retain moisture in the soil and suppress weeds, but don't pile it up against the stems.

Deadheading is key to keeping your Calendula plants blooming throughout our long growing season. Regularly remove spent flowers to encourage the plant to produce more blooms. Simply snip off the flower heads just below the bloom.

You can deadhead anytime you see a faded flower. Towards the end of the season, around the time of our first frost in mid- December, you can either let the last flowers go to seed if you want them to self-sow, or you can cut back the plants to tidy them up for winter.

You can expect your first Calendula harvest about 45 days after planting, so from early March through late December. The flowers are ready to harvest when they are fully open. The petals are most flavorful and have the highest medicinal properties at this stage.

To harvest, simply snip off the flower heads with scissors or pruning shears. Be gentle to avoid damaging the plant. Harvesting regularly encourages more blooms, so keep at it!

As the first frost approaches in mid- December, you can harvest any remaining flowers and dry them for later use. If you leave some flowers on the plant, they will form seeds that you can collect and save for next year.

Powdery Mildew

• What it looks like: White or grayish powdery coating on the leaves, stems. Leaves might curl, yellow, and eventually die.
• What causes it: Powdery mildew loves our warm days, cooler nights, and high humidity. It's a fungus that thrives when there's not enough air circulation.
• How to fix/prevent it: Give your plants plenty of space when planting, and prune to improve air flow. Remove any affected leaves right away. You can spray with neem oil or potassium bicarbonate, but milk spray (1 part milk to 9 parts water) is surprisingly effective.

Aphids

• What it looks like: Clusters of tiny green, black, or white bugs on stems and the undersides of leaves. You might also see a sticky residue called honeydew, and the new growth can look curled or distorted.
• What causes it: These sap-sucking insects reproduce like crazy in warm weather. Ants might even be farming them for the honeydew.
• How to fix/prevent it: A strong blast of water from the hose will knock them off. Encourage ladybugs and lacewings – they're natural predators. Insecticidal soap or neem oil works well for bigger infestations. Avoid over-fertilizing with nitrogen, as that attracts them.

Whiteflies

• What it looks like: Tiny white, moth-like insects that fly up when you disturb the plant. Leaves may turn yellow, appear mottled, and drop prematurely.
• What causes it: Whiteflies are another sap-sucking pest that thrives in warm, humid conditions. They often congregate on the undersides of leaves, making them difficult to spot early on.
• How to fix/prevent it: Similar to aphids, a strong spray of water can dislodge them. Yellow sticky traps are effective for catching adults. Insecticidal soap or neem oil can help control infestations. Ensure good air circulation around plants.

Gulf Coast Specific Challenges: The high humidity in the Gulf Coast makes Calendula more susceptible to fungal diseases like powdery mildew. Regular monitoring and good air circulation are key. Also, our wet-year-round rainfall can lead to overwatering if you're not careful, so make sure your soil is well-draining.

Calendula makes a great companion plant for several vegetables in the Gulf Coast garden. Plant them near tomatoes and peppers to attract beneficial insects like ladybugs and lacewings, which will help control aphids and other pests. Calendula also helps repel tomato hornworms.

Calendula is also a good companion for green beans. It helps to deter bean beetles and other pests that can damage the plants. I wouldn't recommend planting Calendula near members of the cabbage family, like broccoli or cauliflower, as they may attract cabbage moths.