Chrysanthemum in Zone 7A — Southeast

Chrysanthemums, with their vibrant colors and late-season blooms, are a welcome sight in any Southeast garden. They bring a burst of cheer just as other flowers are fading, and they make fantastic cut flowers to brighten your home. Plus, their relatively easy care makes them a rewarding choice for gardeners of all levels in our region.

Our hot and humid summers here in the Southeast can present challenges, but with proper timing and a few preventative measures, you can successfully grow beautiful chrysanthemums. Our long 225-day growing season gives you plenty of opportunity to enjoy these beauties.

Starting Chrysanthemum seeds indoors isn't always necessary, especially if you're buying starts from a local nursery in the spring. However, if you want specific varieties or are eager to get a head start, it's certainly doable.

Start your seeds indoors from late January through mid February, about eight weeks before you plan to transplant them outdoors. Use seed trays with a good seed-starting mix, and provide warmth and plenty of light – a grow light works wonders. Bottom watering is a great way to keep the soil consistently moist without overwatering, which can be a problem in our humid climate.

Transplanting your Chrysanthemum seedlings outdoors should happen from late March through late April. This timing allows you to avoid any late frosts while giving the plants ample time to establish before the full heat of summer arrives. You can also find potted mums already blooming at local nurseries in the fall, or smaller starts in the spring.

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. Even in late March and April, keep an eye out for unexpected temperature swings and be prepared to cover your transplants if a late frost is predicted.

Watering correctly is key to healthy Chrysanthemums in our hot and humid Southeast climate. While they need consistent moisture, overwatering can lead to fungal diseases, a common problem in our region.

During the spring and fall, when temperatures are milder, water deeply once or twice a week, providing about an inch of water each time. In the heat of the summer, you might need to water every other day, especially if we're experiencing a dry spell. Always check the soil moisture first by sticking your finger about two inches deep – if it feels dry, it's time to water. Aim to water at the base of the plant to avoid wetting the foliage, which can encourage fungal growth in our humid environment.

Signs of underwatering include wilting leaves and dry, crispy edges. Overwatering, on the other hand, can cause yellowing leaves and potentially root rot. A layer of mulch around your plants can help retain moisture and suppress weeds, just be sure to keep the mulch a few inches away from the stems to prevent rot.

Pruning Chrysanthemums is essential for encouraging bushier growth and more abundant blooms. The key is to pinch off the growing tips regularly early in the season.

Start pinching the growing tips every two to three weeks, beginning in the spring and continuing until around July 4th. This encourages the plant to branch out and produce more flowering stems. After July 4th, stop pinching to allow the flower buds to develop. As the first frost approaches around early November, you can cut back the plants to a few inches above the ground to prepare them for winter.

You can expect your first Chrysanthemum blooms from early June through late July, depending on the variety and when you transplanted them. Chrysanthemums are fall-blooming, so this might seem early, but some varieties bloom earlier than others.

The flowers will last for weeks in the garden, providing a beautiful display. When cutting for bouquets, choose stems with fully open flowers. Use sharp, clean pruners to make the cut, and strip off any leaves that will be below the waterline in your vase. Continued production relies on regular watering and deadheading spent blooms. As the first frost approaches in early November, you can still cut any remaining blooms to enjoy indoors, but the plant's main show is over for the season.

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

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:* Rapidly reproducing sap-sucking insects thrive in warm weather. Ant colonies may even farm them for honeydew. *How to fix/prevent it:* A strong spray of water can knock them off. Encourage ladybugs and lacewings to visit your garden, as they are natural predators. For heavy infestations, use insecticidal soap or neem oil. Avoid excess nitrogen fertilizer, which attracts aphids.

Spider Mites *What it looks like:* Fine stippling (tiny white dots) on leaves. You might also see fine webbing on leaf undersides and between stems. Leaves can turn bronze or yellow. *What causes it:* These tiny arachnids thrive in hot, dry conditions. Populations explode during periods of drought stress. *How to fix/prevent it:* A strong spray of water daily for a week is often enough. Increase humidity around your plants. Use neem oil or insecticidal soap. You can also release predatory mites. Avoid broad-spectrum pesticides that kill beneficial predators.

Leaf Miners *What it looks like:* Tan, winding trails or blotches within the leaves. *What causes it:* Larvae of small flies that tunnel between the leaf surfaces, feeding on the tissue inside. *How to fix/prevent it:* Remove and destroy affected leaves as soon as you see them. Insecticidal soap or neem oil can help control infestations. Row covers can 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 the undersides. Leaves may 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 promptly. Avoid overhead watering to keep foliage dry. Improve air circulation around the plants. Apply sulfur or copper fungicide if needed. Don't work among wet plants, as this can spread the spores. Rotate your crops to avoid buildup of the fungus in the soil.

Southeast Specific Challenges: Our hot and humid summers create ideal conditions for fungal diseases like rust, so good air circulation and avoiding overhead watering are crucial. Japanese beetles can also be a nuisance, so be prepared to handpick them or use appropriate controls. Deer can also be a problem in some areas, so consider fencing or deer-resistant sprays.

Chrysanthemums can benefit from having the right companions in your Southeast garden. Tomatoes and peppers make good companions because they don't compete for the same nutrients and can help to deter some pests. Lettuce can also be a good choice, as it provides ground cover that helps to retain moisture in our clay soil.

Avoid planting Chrysanthemums near members of the cabbage family, as they can attract similar pests like aphids. Also, avoid planting near mint, as it can be invasive and compete for resources.