Mint in Zone 7B — Texas

Mint is a fantastic addition to any Texas garden. Its refreshing flavor elevates everything from iced tea to summer salads, and a sprig of fresh mint is the perfect garnish for a cool drink on a hot day. Plus, the satisfaction of growing your own herbs in the Texas sunshine is hard to beat.

Our unpredictable weather can be a challenge, but with a little planning, you can enjoy a bountiful harvest of mint. Our long growing season, lasting about 255 days, gives you plenty of time to get your mint established and thriving.

Starting mint indoors is possible, but honestly, it's usually easier to buy starts or get a division from a friend. However, if you're set on starting from seed, begin in early to late January, about eight weeks before the time you’d like to transplant.

Use seed trays with a good seed-starting mix. Keep the soil consistently moist—bottom watering can help with this—and provide warmth and light. A heat mat and grow light will improve germination rates, especially with our early spring temperature swings.

Transplant your mint outdoors from early March through early April. Before planting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week.

Space your plants 18-24 inches apart. Mint spreads aggressively, so consider planting it in a container to keep it from taking over your garden. The weather at this time of year in Texas can be unpredictable, so keep an eye on the forecast for late freezes.

Mint loves moist soil, which can be a bit of a balancing act in Texas. During the hottest part of the summer, from late June through August, you'll likely need to water deeply several times a week, possibly daily if it's particularly dry and your mint is in full sun. Aim for about an inch of water per week, adjusting based on rainfall.

Use the "finger test": stick your finger about two inches into the soil. If it feels dry, it's time to water. Water at the base of the plant to avoid promoting fungal diseases, especially with our variable humidity.

Signs of underwatering include wilting leaves and dry soil. Overwatering can lead to yellowing leaves and root rot. A good layer of mulch, like shredded bark or straw, can help retain moisture in the soil and suppress weeds, which is especially helpful in our climate.

Pruning mint is essential to keep it under control and encourage healthy growth. Throughout the growing season, from spring through fall, regularly harvest stems by cutting them back. This not only provides you with fresh mint but also prevents the plant from flowering, which can diminish the flavor of the leaves.

Don't be afraid to cut back aggressively – mint is a vigorous grower! As the first frost approaches in mid- November, give your mint a final trim. You can either leave it in place for the winter, where it will likely die back and regrow in the spring, or dig up some roots to overwinter indoors.

Your first harvest of mint should be ready from early May through late June, about 60 days after transplanting. You can harvest leaves and stems anytime, but the flavor is most intense just before the plant flowers.

Look for healthy, vibrant leaves with a strong aroma. To harvest, simply pinch or cut off stems just above a leaf node. Pinching off flower buds will encourage continued leaf production.

As the first frost approaches in mid- November, harvest any remaining mint leaves to dry or freeze for later use. You can also bring a potted mint plant indoors to enjoy fresh mint throughout the winter.

Rust

• What it looks like: Rusty orange, yellow, or brown pustules appear on the undersides of leaves and stems. Leaves may yellow and drop prematurely.
• What causes it: Rust fungi thrive in warm, humid conditions, especially when leaves stay wet. Our unpredictable rainfall and variable humidity can create ideal conditions for rust.
• How to fix/prevent it: Remove affected leaves promptly. Avoid overhead watering to keep leaves dry. Improve air circulation by spacing plants adequately. Apply sulfur or copper fungicide if needed. Rotate crops to prevent buildup of the fungus in the soil.

Spider Mites

• What it looks like: Fine stippling (tiny white dots) appears on leaves. You might see fine webbing on leaf undersides and between stems. Leaves can turn bronze or yellow.
• What causes it: Spider mites thrive in hot, dry conditions, and populations can explode during periods of drought, which we often experience in Texas.
• How to fix/prevent it: A strong spray of water, applied daily for about a week, is often effective. Increase humidity around plants. Neem oil or insecticidal soap can also help. Avoid broad-spectrum pesticides that kill beneficial insects that prey on spider mites.

Invasive Spreading

• What it looks like: Mint rapidly spreads beyond its intended area, sending out runners that root and create new plants.
• What causes it: Mint's aggressive growth habit allows it to quickly colonize new areas, especially in our long growing season.
• How to fix/prevent it: Plant mint in containers to restrict its spread. Regularly trim back runners and remove unwanted plants. Consider using a root barrier to prevent underground spread.

Powdery Mildew

• What it looks like: A white or grayish powdery coating appears on leaves, stems, and sometimes fruit. Leaves may curl, yellow, and die.
• What causes it: Powdery mildew thrives in warm days, cool nights, and moderate humidity. Surprisingly, dry leaf surfaces favor it, which can be common even in our humid Texas climate.
• How to fix/prevent it: Improve air circulation by spacing plants properly and pruning as needed. Remove affected leaves. Neem oil or potassium bicarbonate sprays can help. Milk spray (1 part milk to 9 parts water) is also surprisingly effective.

Texas Specific Challenges: Our hot-to-extreme heat, variable humidity, and unpredictable rainfall can create a challenging environment for growing mint. Be vigilant about watering during dry spells, providing shade during the hottest part of the day, and monitoring for pests and diseases. Also, be mindful of fire ants when working in the garden.

Mint is a great companion plant for tomatoes and peppers, as its strong scent can help repel certain pests that bother these vegetables. Cabbage and broccoli also benefit from being planted near mint, as it can deter cabbage moths and other brassica pests.

Avoid planting mint near parsley and chamomile. Mint can inhibit the growth of parsley, and chamomile prefers drier conditions than mint, making them incompatible companions in a Texas garden.