Chrysanthemum in Zone 10A — Florida

Chrysanthemums bring vibrant color and classic beauty to your Florida garden, especially when many other flowers are slowing down. They're perfect for cut flower arrangements and add a cheerful touch to the cooler months. Growing your own gives you unique varieties not found at the local garden center, and a real sense of accomplishment.

Our Florida gardening calendar is different, and while the summer heat can be tough, timing your Chrysanthemum planting right allows you to enjoy them during our prime growing season. With our 355-day growing season, you can plant in fall and harvest in winter. You can definitely make it work!

Starting Chrysanthemums from seed indoors is an option, but honestly, you'll often find success buying established plants. If you're set on starting from seed, begin in early to late November, about eight weeks before you plan to transplant.

Use seed trays with a good seed-starting mix. Keep them warm and provide plenty of light, either from a sunny window or a grow light. Bottom watering helps prevent damping-off, a common problem with seedlings. Remember our spring character is reversed, so getting these going indoors while it's still warm gives them a head start for our cooler months.

Transplant your Chrysanthemums outdoors from early January through early February. This is when the weather is cooler, and they'll have time to establish before our brief warm-season.

Before transplanting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week. Plant them 12-18 inches apart in a sunny spot with well-draining soil. Keep an eye on the weather, as we can sometimes have unexpected cold snaps during this time of year. You can also buy potted mums in fall, or starts in spring.

Watering is crucial for Chrysanthemums, especially in our Florida climate. They need consistent moisture, but overwatering can lead to fungal problems, given our high humidity.

During the cooler months (late fall through early spring), water deeply when the top two inches of soil feel dry to the touch – use the finger test! Aim for about 1 inch of water per week, delivered at the base of the plant to avoid wetting the foliage. In our wet-summer, rainfall might be enough, but keep an eye on them during drier spells.

Signs of underwatering include wilting leaves and dry, crispy edges. Overwatering can cause yellowing leaves and root rot. Mulching around your Chrysanthemums with pine straw or wood chips helps retain moisture and suppress weeds, which is always a win in our Florida gardens.

Pruning is important for encouraging bushier growth and more flowers on your Chrysanthemums. You'll want to pinch the growing tips every 2-3 weeks through July 4th.

Pinching means removing the top set of leaves on a stem. This encourages the plant to send out side shoots, resulting in a fuller plant with more blooms. Make sure to stop pinching after July 4th, as this allows the flower buds to develop. As the first frost approaches in late December, you can cut back the plants to a few inches above the ground.

You can expect your first Chrysanthemum harvest from late March through early May, depending on the variety and when you transplanted. The flowers are ready to harvest when they are fully open and the petals are firm.

Cut the stems at an angle, leaving several inches of stem on the plant to encourage continued production. Removing spent flowers, or "deadheading," also helps prolong the blooming period. Chrysanthemums are continuous bloomers, so you can enjoy fresh flowers for weeks. As the first frost approaches in late December, you can still cut any remaining blooms to enjoy indoors.

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

Aphids *What it looks like:* Clusters of tiny green, black, or white insects on stems and leaf undersides. You might also see sticky honeydew and curled or distorted new growth. *What causes it:* Rapid-reproducing sap-sucking insects that thrive in warm weather. Ant colonies often farm them. *How to fix/prevent it:* Strong water spray knocks them off. Encourage ladybugs and lacewings. Use insecticidal soap for heavy infestations or neem oil systemically. Avoid excess nitrogen fertilizer.

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:* Tiny arachnids that thrive in hot, dry conditions. Populations explode during drought stress. *How to fix/prevent it:* Strong water spray (daily for a week) is the best treatment. Increase humidity around plants. Use neem oil or insecticidal soap. Release predatory mites. Avoid broad-spectrum pesticides.

Leaf Miners *What it looks like:* Tan, brown, or white winding trails or blotches inside the leaf tissue. *What causes it:* Larvae of small flies, moths, sawflies, or beetles that burrow inside the leaves. *How to fix/prevent it:* Remove and destroy affected leaves. Use yellow sticky traps to catch adult flies. Apply neem oil or spinosad. Cover plants with row covers to prevent adults from laying eggs.

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 that spread via 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. Don't work among wet plants. Rotate crops.

Florida Specific Challenges: Our hot, humid summers and wet-summer rainfall create ideal conditions for fungal diseases like rust. Consistent monitoring and good air circulation are key to preventing problems. Also, our sandy soil means you'll need to amend it well with organic matter to improve drainage and nutrient retention, and nematodes are always a consideration.

Good companions for Chrysanthemums include tomatoes and peppers. The strong scent of Chrysanthemums can help deter pests that bother tomatoes and peppers. Lettuce also benefits from the shade provided by Chrysanthemums, especially during our warmer months.

Avoid planting Chrysanthemums near sunflowers, as they compete for the same nutrients and can attract similar pests. Also, keep them away from brassicas like cabbage and broccoli, as they can attract aphids that will then spread to your Chrysanthemums.