Chrysanthemum in Zone 8B — Florida

Chrysanthemums, or mums, are a fantastic addition to the Florida garden. They bring vibrant color when many other blooms are fading and are perfect for cut flowers. Plus, their bushy growth habit helps fill in garden spaces as other plants slow down in the cooler months.

While Florida's humidity and sandy soil can present challenges, the timing for growing mums actually works in our favor. By planting in fall, you'll side-step the worst of the summer heat and give these beauties a chance to thrive during our extended 303-day growing season.

Starting Chrysanthemums from seed indoors isn't the most common approach here, but it's an option if you're looking for specific varieties. If you want to start seeds, aim for mid December through early January, about eight weeks before you plan to transplant.

Use seed trays with a good seed-starting mix and keep them warm and consistently moist. Bottom watering helps prevent damping-off, which can be a problem with our humidity. Remember, our spring is reversed – you're trying to get a head start on a plant that will really take off in the cooler months.

Transplanting is the way to go with Chrysanthemums in Florida. You can either buy established plants in the fall or start with transplants you've grown indoors. Aim to get them in the ground mid February through mid March.

Before transplanting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week. Space them 12-18 inches apart in a sunny spot. Keep an eye on the weather – those late cold snaps can still happen, so be ready to cover them if needed.

Watering is critical for Chrysanthemums here in Florida, especially with our sandy soil. They need consistent moisture but don't like soggy feet. During the fall and winter, when rainfall is less frequent, aim for about 1 inch of water per week.

Use the finger test – stick your finger about 2 inches into the soil. If it feels dry, it's time to water. Always water at the base of the plant to avoid wetting the foliage, which can encourage fungal diseases in our humid climate.

In the summer, even though it's the "slow season," keep an eye on your mums if you're trying to overwinter them. While we get plenty of rain, the intense heat can dry things out quickly. Mulching around the base of the plants with pine straw or wood chips helps retain moisture and keeps the soil cooler. Yellowing leaves can indicate overwatering, while wilting leaves signal underwatering.

Pruning Chrysanthemums is key to getting those beautiful, bushy plants loaded with blooms. The trick is to pinch off the growing tips every 2-3 weeks until around July 4th. This encourages the plant to branch out and produce more flower buds.

Just pinch off the top set of leaves on each stem, leaving the rest of the foliage intact. After July 4th, stop pinching so the plant can focus on developing those fall blooms. After the first frost around mid- December, you can cut the plants back to a few inches above the ground.

You can expect your first Chrysanthemum blooms to appear late April through mid June. They are fall-blooming, so the late harvest is just for the very early bloomers. The flowers last for weeks in the garden, providing a long-lasting splash of color.

Harvest them for bouquets when the flowers are fully open. Cut the stems at an angle, just above a leaf node. This encourages new growth and continued blooming.

To keep your plants producing, deadhead spent flowers regularly. As the first frost approaches (mid- December), you can cut the remaining flowers to enjoy indoors.

Chrysanthemums can face a few common problems in Florida's climate:

Aphids

• What it looks like: Clusters of tiny green, black, or white insects on stems and leaf undersides. Sticky honeydew residue. Curled or distorted new growth.
• What causes it: These sap-sucking insects thrive in warm weather and can multiply rapidly. Ants often protect them.
• How to fix/prevent it: A strong spray of water can knock them off. Encourage ladybugs and lacewings. Use insecticidal soap or neem oil for heavy infestations. Avoid over-fertilizing with nitrogen.

Spider Mites

• What it looks like: Fine stippling on leaves (tiny white dots). Fine webbing on leaf undersides and between stems. Leaves turn bronze or yellow.
• What causes it: These tiny arachnids love hot, dry conditions. Drought stress makes them worse.
• How to fix/prevent it: A strong spray of water daily for a week is effective. Increase humidity. Use neem oil or insecticidal soap. Release predatory mites.

Leaf Miners

• What it looks like: Tan, squiggly lines or blotches inside the leaves.
• What causes it: Larvae of small flies tunnel between the leaf surfaces, feeding as they go.
• How to fix/prevent it: Remove and destroy affected leaves promptly. Use yellow sticky traps to catch adult flies. Spinosad is effective against leaf miner larvae.

Rust

• What it looks like: Rusty orange, yellow, or brown pustules on leaves and stems, mostly on undersides. Leaves yellow and drop prematurely.
• What causes it: Various rust fungi spread by wind-borne spores. Favored by warm, humid conditions with moisture on leaves.
• How to fix/prevent it: Remove affected leaves. Avoid overhead watering. Improve air circulation. Apply sulfur or copper fungicide. Rotate crops.

Florida Specific Challenges: The combination of high humidity and summer heat makes Chrysanthemums particularly susceptible to fungal diseases like rust. Good air circulation and avoiding overhead watering are crucial. Additionally, our sandy soil means you'll need to be diligent about watering and fertilizing to keep your plants healthy and resistant to pests and diseases.

Good companions for Chrysanthemums in the Florida garden include tomatoes and peppers. These plants benefit from the mums' ability to repel certain pests, like aphids. Lettuce also works well, as it enjoys similar growing conditions and can provide ground cover to help retain moisture in our sandy soil. Avoid planting mums near plants susceptible to nematodes, as mums can sometimes be affected, and you don't want to concentrate the problem.