Lemon Balm in Zone 7B — Southeast

Lemon Balm is a fantastic addition to any Southeast garden. Its lemony scent and flavor brighten teas, salads, and even desserts. Plus, it’s incredibly easy to grow here, adding a cheerful, low-maintenance touch to your herb garden.

While our summers are hot and humid, and we have to watch out for pests, Lemon Balm thrives with a little attention to timing. Our long 235-day growing season gives you plenty of opportunity to enjoy this herb.

Starting Lemon Balm indoors gives you a head start, but it’s not strictly necessary. If you want to get harvesting as early as possible, sow seeds indoors from late January through mid February, about six weeks before the last expected frost.

Use seed trays or small pots filled with a good seed-starting mix. Keep the soil consistently moist by bottom watering – set the tray in a shallow dish of water and let the soil soak it up from the bottom. This helps prevent damping off. Provide warmth (around 70°F) and plenty of light, either from a sunny windowsill or a grow light. Our moderate spring means you have a good window for transplanting later.

Transplant your Lemon Balm seedlings outdoors from mid March through mid April. Before planting, 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.

Choose a spot with full sun to partial shade, spacing plants 18-24 inches apart. Keep an eye on the weather forecast – a late cold snap can happen, so be ready to cover your seedlings if needed.

Direct sowing Lemon Balm is a simple and effective method, especially if you're not in a rush for an early harvest. Sow seeds directly into the garden from mid March through mid August. You have a long window here!

Prepare the soil by loosening it and removing any weeds. Lemon Balm isn't too picky, but it appreciates well-drained soil. Sow seeds thinly and cover them lightly with soil. Keep the soil consistently moist until germination. Thin seedlings to 18-24 inches apart once they're a few inches tall.

Lemon Balm likes consistent moisture but doesn't want to be waterlogged. In our hot, humid Southeast climate, watering needs careful attention. During the hotter months, you might need to water a few times a week.

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. Water at the base of the plant to avoid getting the leaves wet, which can encourage fungal diseases in our humid climate.

Signs of underwatering include wilting and yellowing leaves. Overwatering can lead to root rot, indicated by yellowing leaves and a mushy stem. A layer of mulch around the base of the plant helps retain moisture and suppress weeds. Pine straw or shredded hardwood bark works well in our region.

Lemon Balm requires minimal pruning, but a little attention keeps it healthy and productive. In midsummer, cut the plant back by about half to prevent it from becoming leggy and encourage fresh growth.

Remove any flower stalks as soon as you see them to prevent self-seeding. Lemon Balm can be quite aggressive, and you don't want it taking over your garden! At the end of the season, after the first frost (usually around early November here), you can cut the plant back to the ground. It will come back strong in the spring.

You can start harvesting Lemon Balm leaves as soon as the plant is established, usually about 70 days after planting. In our Southeast climate, this means you can expect your first harvest from late May through mid November. The flavor is best before the plant flowers, so harvest frequently.

Simply snip off the leaves you need with scissors or your fingers. Avoid taking more than a third of the plant at any one time to allow it to continue growing. Regular harvesting encourages new growth and keeps the plant productive throughout the season. As the first frost approaches in early November, harvest any remaining leaves you want to use and consider drying or freezing them for later.

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

Aggressive Spreading

• What it looks like: Lemon Balm popping up in unwanted areas of your garden.
• What causes it: Self-seeding and spreading roots.
• How to fix/prevent it: Remove flower stalks before they go to seed. Consider growing it in a container. Dig up and remove unwanted plants regularly.

Bolting

• What it looks like: Plant sends up a flower stalk prematurely. Leaves may become bitter.
• What causes it: Triggered by heat and long days, common during our Southeast summers.
• How to fix/prevent it: Provide afternoon shade. Keep the soil consistently moist. Harvest leaves frequently to delay bolting.

Powdery Mildew

• What it looks like: White or grayish powdery coating on leaves.
• What causes it: Fungi that thrive in our warm days, cool nights, and moderate humidity.
• How to fix/prevent it: Improve air circulation by spacing plants properly. Remove affected leaves. Apply neem oil or potassium bicarbonate spray.

Southeast Specific Challenges: The hot, humid summers and wet-summer rainfall in the Southeast create ideal conditions for powdery mildew. Regular monitoring and preventative measures like proper spacing and watering at the base of the plant are crucial for keeping your Lemon Balm healthy.

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

Good companions:

• Tomato: Lemon Balm repels some pests that bother tomatoes, like whiteflies and tomato hornworms.
• Squash: The strong scent of Lemon Balm can deter squash bugs and vine borers.
• Broccoli and Cauliflower: Lemon Balm can help repel cabbage moths, which can devastate these crops.

Bad companions:

• None known. Lemon Balm is generally a good neighbor in the garden.