Lemon Balm in Zone 9A — Florida

Lemon Balm is a fantastic addition to any Florida garden. Its lemony scent and flavor brighten teas, salads, and other dishes, plus it's incredibly easy to grow here. The satisfaction of snipping fresh herbs from your own garden, especially during our mild winters, is a treat.

Our Florida gardening calendar is different, and summer is the slow season. But with Lemon Balm, you can plant in fall, harvest in winter, and enjoy its benefits throughout much of our 327-day growing season. Just be mindful of our humidity and potential fungal issues.

Starting Lemon Balm indoors isn't essential, but it's an option if you want a head start, especially for an early spring harvest. Begin in mid December through early January, about six weeks before you'd like 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 keep the soil evenly damp without disturbing the tiny seeds. Place the tray in a shallow dish of water and let the soil soak it up from the bottom. Remember, our spring character is reversed, so getting a jump start indoors can help you beat the heat.

Transplant your Lemon Balm seedlings outdoors in early February through early March. Before transplanting, harden them off by gradually exposing them to outdoor conditions for about a week. Start with an hour or two of shade and increase the time and sun exposure each day.

Space your Lemon Balm plants 18-24 inches apart in a well-drained area. Keep an eye on the weather; we can still get some cool snaps during this time, so be ready to cover them if a frost threatens.

Direct sowing Lemon Balm is a straightforward option, and often works well in our climate. Sow seeds directly into the garden from early February through early October. The soil temperature should be at least 60°F for good germination.

Prepare the soil by loosening it and mixing in some compost. Sow the seeds thinly, and keep the soil consistently moist. Once the seedlings emerge, thin them to 18-24 inches apart. Direct sowing is a simple way to get Lemon Balm established, but you'll need to be diligent about watering, especially during our dry spring.

Lemon Balm needs moderate watering to thrive in our Florida climate. While it appreciates moisture, it doesn't like to be waterlogged. The key is to find the right balance, especially considering our high humidity and wet-summer rainfall.

During the spring and fall, when the weather is milder, check the soil moisture regularly using the "finger test." Stick your finger about 2 inches deep into the soil. If it feels dry, it's time to water. Aim for about 1 inch of water per week, either from rainfall or irrigation. In the heat of summer, you might need to water more frequently, but be cautious not to overwater.

Water at the base of the plant to avoid wetting the leaves, which can encourage fungal diseases in our humid environment. Overhead watering is fine if done early in the morning so the leaves have time to dry. Signs of underwatering include wilting and yellowing leaves, while overwatering can lead to root rot and a generally unhealthy appearance.

Mulching around your Lemon Balm plants with pine straw or wood chips helps retain moisture in the soil and suppress weeds. This is especially helpful in our sandy soil, which tends to drain quickly.

Pruning Lemon Balm is fairly minimal, but it's important for maintaining its shape and preventing it from becoming too leggy. In midsummer, cut the plant back by about half to encourage bushier growth. This also helps prevent it from getting too unruly.

Remove any flower stalks as they appear, unless you want the plant to self-seed. Lemon Balm can be quite aggressive in spreading, so removing the flowers is a good way to keep it in check. As our first frost approaches around late December, you can give the plant a final trim to tidy it up for the winter.

You can start harvesting Lemon Balm leaves as early as mid April and continue through early January, about 70 days after planting. The leaves have the best flavor before the plant flowers, so keep an eye out for flower stalks and harvest before they open.

To harvest, simply snip off the leaves you need with scissors or garden shears. Avoid pulling the leaves, as this can damage the plant. Regular harvesting encourages continued production, so don't be shy about using your Lemon Balm.

As the first frost approaches in late December, you can harvest the remaining leaves and either use them fresh or preserve them for later. While Lemon Balm loses some of its flavor when dried, it's still a useful herb to have on hand.

Here are some common problems you might encounter with Lemon Balm in Florida:

Aggressive Spreading

• What it looks like: Lemon Balm popping up in unwanted areas of your garden, spreading beyond its intended space.
• What causes it: Lemon Balm readily self-seeds and can spread quickly through underground rhizomes.
• How to fix/prevent it: Remove flower stalks before they go to seed. Consider growing Lemon Balm in a container to limit its spread. Regularly pull up any unwanted seedlings.

Bolting

• What it looks like: The plant sends up a flower stalk prematurely, and the leaves become bitter or tough.
• What causes it: Bolting is often triggered by heat, long days, or drought stress.
• How to fix/prevent it: Plant Lemon Balm in a location that gets some afternoon shade, especially during the hottest months. Keep the soil consistently moist. Remove flower stalks as soon as they appear to encourage continued leaf production.

Powdery Mildew

• What it looks like: A white or grayish powdery coating on the leaves, stems, and sometimes the fruit. Leaves may curl, yellow, and die.
• What causes it: Powdery mildew is caused by various fungi that thrive in warm days, cool nights, and moderate humidity.
• How to fix/prevent it: Improve air circulation by spacing plants properly and pruning. Remove affected leaves. Apply neem oil or potassium bicarbonate sprays. A milk spray (1 part milk to 9 parts water) can also be effective.

Florida Specific Challenges: Our hot heat, very-high humidity, and wet-summer rainfall can exacerbate these problems. Pay close attention to watering practices, ensuring good drainage to prevent root rot. Consistent monitoring for pests and diseases is key to keeping your Lemon Balm healthy and productive in our unique climate.

Lemon Balm makes a great companion plant for several vegetables in your Florida garden.

Good companions:

• Tomato: Lemon Balm can help repel certain pests that attack tomatoes, like whiteflies and tomato hornworms.
• Squash: Lemon Balm can attract beneficial insects that pollinate squash flowers, leading to better yields.
• Broccoli and Cauliflower: Lemon Balm can deter cabbage moths, which can be a major problem for these brassicas.

Bad companions:

• Avoid planting Lemon Balm near other herbs like rosemary or basil. Lemon Balm’s aggressive growth can overwhelm these slower-growing herbs and compete for resources.