Mint in Zone 8A — Southeast

Mint is a fantastic herb to grow in the Southeast. The fresh, clean flavor is wonderful in everything from sweet tea to summer salads, and it's incredibly satisfying to have a ready supply right outside your door. Plus, mint thrives in our long summer growing season, so you'll have plenty to harvest.

We do face some challenges here in the Southeast, like our hot and humid summers that can encourage fungal diseases. But with a little planning and attention to timing, you can easily overcome these issues and enjoy a thriving mint patch throughout our 245-day growing season.

Starting mint seeds indoors is certainly an option, but honestly, it's not usually necessary here in the Southeast. Our moderate spring temperatures and long growing season mean you can easily transplant starts from a local nursery or get a division from a friend. However, if you're after a specific variety or want a head start, you can sow seeds indoors from mid January through early February, about 8 weeks before you plan to transplant.

Use seed trays with a good seed-starting mix, and keep them warm and consistently moist. Bottom watering is a great way to prevent damping off. Place your trays under grow lights or in a very sunny window.

Transplanting mint outdoors should be done from mid March through mid April. Before you move your seedlings outside permanently, harden them off by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the sun and wind.

Plant your mint 18-24 inches apart. Be aware that mint spreads aggressively, so many gardeners in the Southeast prefer to grow it in containers to keep it contained, especially given our clay soil. Keep an eye on the weather forecast, as we can still get some unexpected cool snaps that time of year.

Mint loves moist soil, which makes it generally well-suited to the Southeast's wet-summer climate. However, even with our reliable rainfall, you'll need to pay attention to its watering needs, especially during the hottest parts of our long summer.

Check the soil moisture by sticking your finger about 2 inches deep. If it feels dry, it's time to water. Aim for about 1 inch of water per week, either from rainfall or irrigation. Water at the base of the plant to avoid wetting the leaves, which can encourage fungal diseases in our humid environment.

Signs of underwatering include wilting leaves and slow growth. Overwatering, on the other hand, can lead to yellowing leaves and root rot. A layer of mulch around your mint plants will help retain moisture and suppress weeds, a great benefit in our humid climate.

Pruning mint is more about control and encouraging growth than any specific technique. This plant will happily take over your garden if you let it. The best approach is to cut back aggressively throughout the growing season to keep it contained and encourage new, flavorful growth.

Harvest entire stems regularly, cutting them back to just above a leaf node. This will promote bushier growth. As the first frost approaches around mid- November, give your mint one final haircut. You can either let it die back naturally or try to overwinter it in a pot indoors.

You can expect your first harvest of mint from mid May through early July, about 60 days after transplanting. The best time to harvest is before the plant starts to flower, as the leaves are most flavorful then. However, you can harvest leaves and stems anytime you need them.

To harvest, simply snip off stems with scissors or pruning shears. Pinch off any flower buds you see to encourage continued leaf production. As the first frost approaches in mid- November, harvest any remaining leaves you want to preserve and consider drying or freezing them for use over the winter.

Here are some common problems you might encounter growing mint in the Southeast:

Rust

• What it looks like: Rusty orange, yellow, or brown pustules on the leaves and stems, mostly on the undersides. Leaves yellow and drop prematurely.
• What causes it: Various rust fungi that thrive in our warm, humid conditions, especially when moisture lingers on the leaves.
• How to fix/prevent it: Remove affected leaves promptly. Avoid overhead watering. Improve air circulation by spacing plants properly. Apply sulfur or copper fungicide if necessary. Don't work among wet plants, and rotate crops each year.

Spider Mites

• What it looks like: Fine stippling on the 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. While we have plenty of humidity, a dry spell can still lead to an infestation.
• How to fix/prevent it: A strong spray of water (daily for a week) is often the best treatment. Increase humidity around the plants. Neem oil or insecticidal soap can also be effective. Avoid broad-spectrum pesticides that kill beneficial predators.

Invasive Spreading

• What it looks like: Mint popping up everywhere you don't want it!
• What causes it: Mint sends out underground runners that can quickly colonize a large area, especially in our clay soil.
• How to fix/prevent it: The best solution is to grow mint in containers. If you plant it in the ground, consider burying a barrier around the planting area to contain the roots. Regularly pull up any unwanted shoots.

Powdery Mildew

• What it looks like: White or grayish powdery coating on leaves, stems, and sometimes fruit. Leaves curl, yellow, and die.
• What causes it: Various fungi that thrive in warm days, cool nights, and moderate humidity. Oddly, dry leaf surfaces actually favor it.
• How to fix/prevent it: Improve air circulation through spacing and pruning. Remove affected leaves. Neem oil or potassium bicarbonate sprays can help. A milk spray (1 part milk to 9 parts water) is surprisingly effective.

Southeast Specific Challenges: Our hot and humid summers create a perfect environment for fungal diseases like rust and powdery mildew. Make sure to provide good air circulation, avoid overhead watering, and monitor your plants regularly for any signs of trouble.

Mint can be a great companion plant for many vegetables in the Southeast. Tomatoes and peppers benefit from mint's ability to repel certain pests. Cabbage and broccoli also enjoy mint's protection against cabbage moths and other insects.

Avoid planting mint near parsley or chamomile. Mint can inhibit the growth of parsley, and chamomile may attract pests that also affect mint. Choose your companion plants wisely to create a thriving and pest-free garden.