Chrysanthemum in Zone 6A — Southeast

Chrysanthemums are a fantastic addition to any Zone 6A garden in the Southeast. Their vibrant blooms bring a burst of color to your garden during the long summer and into the early fall, plus they make lovely cut flowers for bouquets. And let's be honest, there's a real satisfaction in successfully growing beautiful flowers despite our challenging climate.

Our hot, humid summers definitely present some hurdles, especially with fungal diseases and pests like Japanese beetles. But the long 198-day growing season gives you plenty of time to get your chrysanthemums established and thriving before the heat really kicks in. Timing is key, and with a little planning, you can enjoy these beauties in your garden.

Starting chrysanthemums from seed indoors isn't super common, since they're so easily found as starts. But if you're after a specific variety, it's a viable option. Start your seeds indoors in early to late February, about eight weeks before you plan to transplant them outside.

Use seed trays with a good seed-starting mix, and keep them in a warm spot with plenty of light – a sunny windowsill or under grow lights works well. Bottom watering is your friend here; it helps prevent damping-off. Our moderate spring here in the Southeast means you don't have to rush, so give those seedlings the time they need to get strong before heading outdoors.

You can find potted mums in the fall, or starts in the spring. Transplant your chrysanthemums outdoors in early April through early May, once the danger of frost has passed. Before planting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week.

Space them 12-18 inches apart to allow for good air circulation – this is crucial to combat fungal diseases in our humid climate. Keep an eye on the weather forecast; those late-season cold snaps can still happen, so be ready to cover your plants if needed.

Watering is critical for chrysanthemums, especially in the Southeast's hot, humid summers. Aim to keep the soil consistently moist, but not waterlogged. A good rule of thumb is to water deeply when the top two inches of soil feel dry to the touch – the "finger test."

During our wet-summer, established chrysanthemums generally need about an inch of water per week, including rainfall. Water at the base of the plant to avoid wetting the foliage, which can encourage fungal diseases. In the hottest part of the summer, you might need to water more frequently. Yellowing leaves can indicate overwatering, while wilting leaves mean they need more water.

Adding a layer of mulch around your plants will help retain moisture and suppress weeds. Pine straw or shredded hardwood mulch works well and helps improve our clay soil over time.

Pruning chrysanthemums is all about encouraging bushier growth and more blooms. Start pinching off the growing tips every 2-3 weeks, starting in the spring and continuing through July 4th. This forces the plant to produce more side shoots, which means more flowers later on.

Just pinch off the top inch or so of the stem, right above a set of leaves. After July 4th, stop pinching, as the plant will start forming its flower buds. In late October, after the first frost, you can cut the plants back to a few inches above the ground to tidy them up for winter.

You can expect your first harvest of chrysanthemum blooms in mid-June through early August, about 70 days after transplanting. The flowers are ready to cut when they are fully open and the petals are firm. They last for weeks in the garden, so you'll have plenty of time to enjoy them.

To harvest, simply cut the stems at an angle, leaving a few inches of stem on the plant. This encourages the plant to produce more flowers. Deadhead spent blooms regularly to keep the plant looking tidy and to promote continued flowering.

As the first frost approaches in late October, you can cut any remaining blooms to bring indoors. The plant will go dormant over the winter, and you can look forward to another beautiful display next year.

Chrysanthemums can face a few common problems in the Southeast. Here's how to tackle them:

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 reproduce rapidly, especially in warm weather. Ants often "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. Use insecticidal soap for heavy infestations or neem oil for a systemic approach. Avoid over-fertilizing with nitrogen.

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

Leaf Miners *What it looks like:* Tan, winding trails and blotches inside the leaves. *What causes it:* These are the larvae of small flies, tunneling between the leaf surfaces. *How to fix/prevent it:* Remove and destroy affected leaves. Use floating row covers to prevent the adult flies from laying eggs. Spinosad is an effective treatment if infestation is heavy.

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:* Rust fungi spread via wind-borne spores and thrive in 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.

Southeast Specific Challenges: The hot, humid summers in the Southeast create ideal conditions for fungal diseases like rust and for pests like aphids and spider mites. Good air circulation, careful watering practices (avoiding wet foliage), and regular monitoring are crucial for keeping your chrysanthemums healthy.

Companion planting can be a great way to improve the health and productivity of your chrysanthemums. Tomatoes and peppers make excellent companions because they can help deter pests like aphids that might otherwise target your chrysanthemums. Plus, they enjoy similar growing conditions – full sun and well-drained soil.

Lettuce can also be a good companion plant, especially when your chrysanthemums are young. The lettuce can provide some shade and help keep the soil cool, which can be beneficial during our hot summers. Avoid planting chrysanthemums near plants that are susceptible to the same diseases, as this can increase the risk of problems.