Chrysanthemum in Zone 9B — Florida

Chrysanthemums add a burst of color to our Florida gardens when many other flowers are fading. Their bright blooms signal the cooler months and provide a welcome change from the heat. Plus, they make beautiful cut flowers to brighten up your home.

Our Florida gardening calendar is different, and chrysanthemums are a perfect example. While other regions might be winding down, we're just getting started with fall planting. With our long, 344-day growing season, we can enjoy these beauties even with our challenges of humidity and occasional temperature dips.

Starting chrysanthemum seeds indoors isn't the most common practice here in Florida, but it can be done if you're looking for specific varieties. Start your seeds from mid-November through early December, about eight weeks before you plan to transplant them outdoors. Use seed trays with a good seed-starting mix, and keep them in a warm, well-lit area, or use a grow light.

Bottom watering is a great way to keep the soil moist without overwatering, which can be a problem with our high humidity. Just set the tray in a shallow dish of water and let the soil soak it up. Remember, our spring character is reversed here, so you're essentially starting these for "fall" blooms.

Transplant your chrysanthemum seedlings outdoors from mid-January through mid-February. Before you do, harden them off by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the Florida sunshine and temperatures, which can still be a bit unpredictable at that time of year.

Space your plants 12-18 inches apart to allow for good air circulation. This is crucial in our humid climate to prevent fungal diseases. You can also find potted mums at local nurseries in the fall if you prefer a more instant display, or purchase starts in the spring.

Watering is critical for chrysanthemums, especially in Florida's unique climate. While they need consistent moisture, our high humidity means we have to be careful not to overwater. Aim for about 1 inch of water per week, but adjust based on rainfall.

The "finger test" is your best friend: stick your finger about 2 inches deep 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, as this can encourage fungal diseases in our humid environment. During our hotter months, you might need to water more frequently, but scale back as temperatures cool.

In general, water deeply but less often, and watch for signs of under or overwatering. Drooping leaves can indicate either problem. Mulching around your plants with pine straw or wood chips helps retain moisture and suppress weeds, a win-win in Florida.

Pinching your chrysanthemums is key to getting those full, bushy plants loaded with blooms. Start pinching the growing tips every 2-3 weeks, beginning when the plants are about 6 inches tall. Continue this through July 4th.

Pinching encourages the plant to branch out, resulting in more stems and, therefore, more flowers. Be sure to stop pinching after July 4th, as this allows the flower buds to develop for your fall display. As the first frost approaches around late December, you can cut back the plants to tidy them up, but leave some foliage for winter protection.

Chrysanthemums are a true delight to harvest in Florida, offering a profusion of color when many other plants are slowing down. Expect your first harvest from late March through mid-May, about 70 days after transplanting. The flowers will last for weeks in the garden, providing a long-lasting display.

Cut the stems for bouquets when the flowers are fully open. Use sharp, clean pruners to avoid damaging the plant. Cutting the flowers encourages the plant to produce more blooms, so keep harvesting regularly.

As the first frost approaches in late December, you can still enjoy the remaining blooms, but know that the plant will soon go dormant. You can cut the stems back to the ground after the first frost, and the plant will likely return in the spring.

Chrysanthemums can face a few challenges in Florida's climate, but with a little attention, you can keep them healthy and blooming. Here are some common problems:

Aphids *What it looks like:* Clusters of tiny green, black, or white insects on stems and leaf undersides. You might also see a sticky honeydew residue and curled or distorted new growth. *What causes it:* These sap-sucking insects thrive in warm weather and can reproduce rapidly. Ant colonies sometimes "farm" them for their honeydew. *How to fix/prevent it:* A strong spray of water can knock them off. Encourage natural predators like ladybugs and lacewings. For heavy infestations, use insecticidal soap or neem oil. Avoid excess nitrogen fertilizer, which attracts aphids.

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 thrive in hot, dry conditions. Populations explode during drought stress. *How to fix/prevent it:* A strong spray of water (daily for a week) is often the best treatment. Increase humidity around plants. Neem oil or insecticidal soap can also help. You can even release predatory mites to control them.

Leaf Miners *What it looks like:* Tan, winding trails or blotches inside the leaves. *What causes it:* These are the larvae of small flies that burrow into the leaves to feed. *How to fix/prevent it:* Remove and destroy affected leaves. Insecticidal soap or neem oil can help control infestations. You can also use floating row covers to prevent the adult flies from laying eggs on the plants.

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, so good air circulation and avoiding overhead watering are crucial. Nematodes in our sandy soil can also be a problem, so consider planting in raised beds or containers with nematode-free soil. Regular monitoring and prompt action are key to keeping your chrysanthemums healthy in Florida.

Chrysanthemums make good companions for several vegetables in the Florida garden. Planting them near tomatoes and peppers can help repel certain pests, thanks to their scent. The flowers also attract beneficial insects that can pollinate your veggies.

Lettuce also benefits from being planted near chrysanthemums. The flowers provide some shade and help keep the soil cooler, which is especially helpful during our warmer months. Avoid planting chrysanthemums near members of the cabbage family (broccoli, cauliflower, kale), as they can attract similar pests.