Mint in Zone 10B — Florida

Mint is a fantastic addition to any Florida garden. The fresh, vibrant flavor elevates everything from mojitos to iced tea, and its vigorous growth provides a constant supply of aromatic leaves. Plus, the satisfaction of growing your own herbs year-round in our subtropical climate is hard to beat.

While our humidity and occasional pests can present challenges, the Florida gardening calendar is different, giving us a long window to establish mint. With a little attention to timing and variety selection, you can enjoy a thriving mint patch almost year-round in our 360-day growing season.

Starting mint from seed indoors isn't always necessary in Florida, but it can give you a head start, especially if you want a specific variety. Begin in early to late November, about 8 weeks before you plan to transplant. Use seed trays with a good seed-starting mix.

Keep the trays warm and provide plenty of light – a simple grow light works well. Water from the bottom by setting the tray in a shallow dish of water to avoid damping off. Remember, our spring character is reversed, so getting a jump start indoors helps beat the summer heat.

Transplant your mint seedlings outdoors from early January through early February. Before planting, harden them off by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the Florida sun and humidity.

Space plants 18-24 inches apart. Mint spreads aggressively, so consider growing it in containers to keep it from taking over your garden. You can also buy starts or get divisions from another gardener, as this is a faster method.

Mint loves consistent moisture, which can be a bit tricky with Florida's alternating wet and dry spells. During our drier periods, especially in spring, check the soil moisture regularly. Stick 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 supplemental watering. Water at the base of the plant to avoid wetting the leaves, which can encourage fungal diseases in our humid climate. During our wet-summer, you may not need to water at all.

Signs of underwatering include wilting and yellowing leaves. Overwatering can lead to root rot, indicated by soggy soil and stunted growth. A layer of mulch, like pine straw, will help retain moisture and suppress weeds.

Pruning mint is essential for controlling its growth and encouraging bushier plants. Throughout the growing season, regularly harvest entire stems, cutting them back to just above a leaf node. This promotes new growth and keeps the plant from getting leggy.

Pinch off any flower buds as they appear to encourage continued leaf production. As our first frost approaches in late December, give your mint a final trim to remove any dead or damaged growth, and it will bounce back in the spring.

You can expect your first harvest of mint from early March through late April, about 60 days after transplanting. The leaves are most flavorful before the plant flowers, so keep an eye out for those buds.

To harvest, simply snip off stems as needed, leaving a few inches of growth at the base. This encourages the plant to produce more leaves. Regular harvesting keeps the plant productive and prevents it from becoming overgrown.

As our first frost approaches in late December, you can harvest the remaining leaves and dry or freeze them for later use. The plant will likely die back in the cooler weather, but it will return in the spring.

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

Rust

• What it looks like: Rusty orange, yellow, or brown pustules on 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 with moisture on the leaves.
• How to fix/prevent it: Remove affected leaves immediately. Avoid overhead watering to keep the leaves dry. Improve air circulation by spacing plants properly. Apply sulfur or copper fungicide if necessary. Don't work among wet plants to avoid spreading the fungus. Rotate crops in future seasons.

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: These tiny arachnids thrive in hot, dry conditions. Populations explode in drought stress.
• How to fix/prevent it: A strong water spray (daily for a week) is often the best treatment. Increase humidity around plants by misting. Neem oil or insecticidal soap can also be effective. Release predatory mites (Phytoseiulus persimilis) to help control the population. 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 spreads aggressively via underground runners.
• How to fix/prevent it: Plant mint in containers to restrict its growth. If planted in the ground, consider burying a barrier around the planting area to prevent the runners from spreading. Regularly monitor and remove 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. Dry leaf surfaces actually favor it.
• How to fix/prevent it: Improve air circulation through spacing and pruning. Remove affected leaves promptly. Neem oil or potassium bicarbonate sprays can help. A milk spray (1 part milk to 9 parts water) is surprisingly effective.

Florida Specific Challenges: Our hot, humid summers and wet-summer rainfall create the perfect environment for fungal diseases like rust and powdery mildew. Monitor your plants closely and take preventative measures like ensuring good air circulation and avoiding overhead watering. Sandy soil also means you'll need to be vigilant about watering, especially during dry spells.

Mint makes a great companion for tomatoes and peppers, as its strong scent can help repel pests like aphids and flea beetles. It also benefits cabbage and broccoli by deterring cabbage moths.

Avoid planting mint near parsley or chamomile. Parsley and mint compete for similar nutrients, while chamomile is thought to inhibit mint's growth. By choosing the right companions, you can create a thriving and productive garden in your Florida backyard.