Calendula in Zone 8A — Florida

Calendula is a fantastic addition to any Florida garden, offering vibrant color and a host of practical uses. The petals add a peppery zest to salads, can be infused into soothing skin balms, and even attract beneficial insects to your vegetable patch. Plus, seeing those bright orange and yellow blooms thriving in your garden is simply satisfying.

Our Florida gardening calendar is different, with summer being the slow season. While the heat and humidity can be challenging, Calendula thrives during our cooler months. With a long growing season of 283 days, you'll have plenty of opportunities to enjoy this versatile flower.

Starting Calendula indoors is an option, but honestly, direct sowing is often easier here in Florida. If you want a head start, though, begin in late December through mid January, about six weeks before you plan to transplant. Use seed trays with a good seed-starting mix, and keep them warm and consistently moist.

Bottom watering is especially helpful to prevent damping off, a fungal disease that can plague seedlings in our humid climate. Place the tray in a shallow dish of water and let the soil absorb moisture from the bottom. Once the soil surface is damp, remove the tray. Remember our spring character is reversed here, so it's always a race against the quickly approaching heat.

Transplant your Calendula seedlings outdoors from mid February through late March. Before transplanting, harden them off by gradually exposing them to outdoor conditions for about a week. Start with an hour or two of shade and increase the time and sunlight exposure each day.

Space the plants 8-12 inches apart in well-draining soil. Keep an eye on the weather; those late-season cold snaps can still happen, so be prepared to cover your seedlings if a frost is predicted.

Direct sowing Calendula is a breeze in Florida, and it's my preferred method. You can sow seeds directly into the garden from mid February through early October. Choose a sunny spot with well-draining soil.

Gently rake the soil surface and scatter the seeds, then lightly cover them with soil. Keep the soil consistently moist until the seedlings emerge. Thin the seedlings to 8-12 inches apart once they have a few sets of true leaves. The soil temperature is usually warm enough during this period to encourage germination.

Calendula prefers moderate watering, which can be tricky in our Florida climate. During the cooler months (fall, winter, and early spring), aim for about 1 inch of water per week, either from rainfall or irrigation. Check the soil moisture before watering; stick your finger about 2 inches deep. If the soil feels dry, it's time to water.

In the hotter months, Calendula may go semi-dormant, so reduce watering frequency. Our wet-summer rainfall can often take care of the watering for you during this time. Always water at the base of the plant to avoid wetting the foliage, which can encourage fungal diseases in our humid environment.

Signs of underwatering include wilting leaves and stunted growth. Overwatering can lead to root rot, indicated by yellowing leaves and a generally unhappy plant. A layer of mulch around the base of your Calendula plants helps retain moisture and suppress weeds, which is especially helpful in our sandy soil.

Deadheading is key to keeping your Calendula plants blooming throughout the season. Regularly remove spent flowers by snipping them off just below the flower head. This encourages the plant to produce more blooms instead of putting energy into seed production.

During the peak of summer, when temperatures soar, your Calendula might slow down or even stop blooming. Continue to deadhead any spent flowers, but don't be surprised if the plant looks a bit tired. As the weather cools down in the fall, it should bounce back. Before our first frost around early December, you can let some of the last flowers mature and go to seed if you want to collect them for next year.

You can expect your first Calendula harvest about 45 days after planting, so roughly from late March through mid December. Harvest the flowers when they are fully open, ideally in the morning after the dew has dried. Simply snip the flower heads off the plant with scissors or pruning shears.

To encourage continued production, harvest regularly. The more you harvest, the more flowers the plant will produce. The petals are the most commonly used part of the flower, and they are edible and medicinal.

As the first frost approaches in early December, harvest any remaining flowers. You can dry them for later use or let some of the last blooms go to seed for next year’s crop.

Here are some common problems you might encounter with Calendula in Florida:

Powdery Mildew

• What it looks like: White or grayish powdery coating on leaves, stems. Leaves curl, yellow, and die.
• What causes it: Various fungi thrive in warm days, cool nights, and moderate humidity, which we often have during our spring and fall. Dry leaf surfaces actually favor it.
• How to fix/prevent it: Improve air circulation by spacing and pruning. Remove affected leaves. Neem oil or potassium bicarbonate sprays can help. A milk spray (1 part milk to 9 parts water) is surprisingly effective.

Aphids

• What it looks like: Clusters of tiny soft-bodied insects (green, black, or white) on stems and leaf undersides. Sticky honeydew residue. Curled or distorted new growth.
• What causes it: Rapid-reproducing sap-sucking insects. Populations explode in warm weather. Ant colonies may farm them for honeydew.
• How to fix/prevent it: Strong water spray knocks them off. Encourage ladybugs and lacewings (natural predators). Insecticidal soap for heavy infestations. Neem oil works systemically.

Whiteflies

• What it looks like: Tiny white, moth-like insects that flutter around the plant when disturbed. Yellowing leaves. Sticky honeydew residue.
• What causes it: Warm weather and high humidity create ideal conditions for whiteflies to thrive. They suck sap from the plant, weakening it.
• How to fix/prevent it: Hang yellow sticky traps to capture adult whiteflies. Spray plants with insecticidal soap or neem oil, making sure to coat the undersides of the leaves. Encourage natural predators like lacewings and ladybugs.

Florida Specific Challenges: Our extreme humidity and wet-summer rainfall create a perfect breeding ground for fungal diseases, so good air circulation and avoiding overhead watering are crucial. While Calendula can tolerate some heat, prolonged exposure to our intense summer sun can stress the plants, making them more susceptible to pests and diseases.

Calendula makes a great companion plant in the Florida garden. It's a good idea to plant Calendula near tomatoes and peppers because it attracts beneficial insects like ladybugs and hoverflies, which prey on aphids and other pests that can plague these vegetables. Plant it near green beans to help deter bean beetles.

I don't recommend planting it near members of the cabbage family like broccoli or cauliflower. Calendula can sometimes attract cabbage moths, which can then lay their eggs on these crops.