Chrysanthemum in Zone 7A — Texas

Chrysanthemums add a pop of color to your fall garden after the brutal Texas heat has faded some. They're great for cut flowers, and the cheerful blooms are a welcome sight as other plants are winding down. Plus, they can attract beneficial insects to your garden, which helps keep pests in check.

Texas weather can be unpredictable, but with a little planning, you can successfully grow mums here. Our long growing season of around 245 days gives you plenty of time to get them established before the first frost. The key is to plant early and be prepared for anything!

Starting chrysanthemum seeds indoors is an option, but honestly, most Texas gardeners find it easier to buy established plants. If you're set on starting from seed, begin in mid January through early February, about eight weeks before you plan to transplant.

Use seed trays with a good seed-starting mix and keep them in a warm spot, around 70-75°F. A heat mat can help. Bottom watering is great for seedlings – just set the tray in a shallow dish of water until the top of the soil is moist. Since spring can come early here, keep an eye on the weather and be ready to adjust your transplant schedule if needed.

Transplant your chrysanthemum seedlings outdoors in mid March through mid April, after the last expected frost. Before transplanting, harden them off by gradually exposing them to outdoor conditions for about a week.

Choose a spot with full sun (at least 6-8 hours a day) and well-drained soil. Space plants 12-18 inches apart. Keep an eye on the weather forecast, as we can get some late freezes or even hail this time of year. Be ready to cover your young plants if needed. Buying established plants from a local nursery in the spring or already-potted mums in the fall is often the easiest way to go here.

Chrysanthemums need consistent moisture, but they don't like to be waterlogged, especially with our variable humidity. During the hot Texas summers, you'll likely need to water them deeply about 2-3 times a week, providing about 1 inch of water each time.

Stick your finger about 2 inches deep into the soil. 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 diseases, particularly when humidity is high. In the spring and fall, you can usually reduce watering to once or twice a week, depending on rainfall.

Signs of underwatering include wilting leaves and dry soil. Overwatering can cause yellowing leaves and root rot. Applying a layer of mulch around your plants helps retain moisture and keeps the soil temperature more consistent. Just avoid piling it up against the stems.

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

Just snip off the top inch or so of the stem, right above a leaf node. Stop pinching around July 4th. This allows the plant to focus on developing flower buds for fall blooming. After the first frost, you can cut back the plant to a few inches above the ground.

Chrysanthemums typically start blooming in late summer or early fall, so expect your first harvest from late May through mid July. The flowers will last for weeks in the garden.

Cut the stems for bouquets when the flowers are fully open. Use sharp, clean pruners to make the cut at an angle, just above a leaf node. This encourages the plant to produce more blooms. Keep deadheading (removing spent flowers) to prolong the blooming period. As the first frost approaches, you can cut all the remaining flowers to bring indoors or leave them for some late-season color in the garden.

Here are some common problems you might encounter with chrysanthemums in Texas:

Aphids

• What it looks like: Clusters of tiny soft-bodied insects (green, black, or white) on stems and leaf undersides. Sticky honeydew residue. Curled or distorted new growth.
• What causes it: Rapid-reproducing sap-sucking insects. Populations explode in warm weather. Ant colonies may farm them for honeydew.
• How to fix/prevent it: Strong water spray knocks them off. Encourage ladybugs and lacewings (natural predators). Insecticidal soap for heavy infestations. Neem oil works systemically. Avoid excess nitrogen fertilizer (it attracts them). Watch out for fire ants protecting them.

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 in drought stress.
• How to fix/prevent it: Strong water spray (daily for a week) is the best treatment. Increase humidity around plants. Neem oil or insecticidal soap. Release predatory mites (Phytoseiulus persimilis). Avoid broad-spectrum pesticides that kill predators.

Leaf Miners

• What it looks like: Tan, winding trails or blotches inside leaves.
• What causes it: Larvae of small flies that tunnel between leaf surfaces, feeding on the tissue.
• How to fix/prevent it: Remove and destroy affected leaves. Use floating row covers to prevent the adult flies from laying eggs. Neem oil can help control infestations.

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.

Texas Specific Challenges: The extreme heat and variable humidity in Texas can make chrysanthemums more susceptible to pests and diseases. Make sure to provide adequate water and air circulation to help them thrive. Also, be prepared to deal with those fire ants – they can make gardening a real challenge!

Chrysanthemums can benefit from companion planting. Tomatoes and peppers make good companions because they can provide some shade during the hottest part of the day, protecting the mums from the worst of the Texas heat. Lettuce can also work well, as it appreciates the slight shade provided by the mums, especially in the spring.

Avoid planting chrysanthemums near anything that requires very dry soil, as they prefer consistent moisture. Also, keep them away from plants that are prone to attracting pests, as this can increase the risk of infestations.