Lemon Balm in Zone 7B — Mid-Atlantic

Lemon Balm is a fantastic addition to any Mid-Atlantic garden. Its lemony scent and flavor brighten teas, salads, and even desserts. Plus, it's incredibly satisfying to grow your own herbs, especially when they thrive in our four seasons.

Our humid summers and variable spring weather can present challenges, but with careful timing and attention, Lemon Balm will flourish in your Zone 7B garden. You have a generous 214-day growing season to work with, so there's plenty of time to get it right.

Starting Lemon Balm indoors gives you a head start, but it's not strictly necessary. If you want earlier harvests or are concerned about variable spring weather, starting indoors is a good option.

Sow seeds indoors from mid-February through early March, about six weeks before you plan to transplant. Use seed trays with good drainage, provide warmth (a heat mat helps), and ensure plenty of light with grow lights. Bottom watering helps prevent damping off; set the tray in a shallow dish of water until the surface soil is moist.

Transplant your Lemon Balm seedlings outdoors in early to late April, once the danger of a hard frost has passed. Before transplanting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week.

Space plants 18-24 inches apart to allow for their bushy growth. Keep an eye on the weather forecast; we sometimes get unexpected cold snaps in April, so be prepared to cover your young plants 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 early April through early August.

Prepare the soil by loosening it and removing any weeds. Lemon Balm prefers well-drained soil, but it's fairly adaptable. Scatter the seeds thinly over the soil surface and gently press them in. Keep the soil consistently moist until germination. Thin seedlings to 18-24 inches apart once they are a few inches tall.

Lemon Balm thrives with moderate watering, which is crucial in our Mid-Atlantic climate with its humid summers. Aim to keep the soil consistently moist, but not waterlogged.

During the spring and fall, when temperatures are milder and rainfall is more frequent, you may only need to water once or twice a week. In the heat of summer, especially during dry spells, you might need to water every other day. Use the finger test: stick your finger about two inches deep into the soil. If it feels dry, it's time to water. Generally, give your Lemon Balm about 1 inch of water per week, either through rainfall or irrigation.

Water at the base of the plant to avoid wetting the foliage, which can encourage fungal diseases in our humid environment. Signs of underwatering include wilting leaves and stunted growth. Overwatering can lead to yellowing leaves and root rot. Mulching around your Lemon Balm plants with a layer of organic matter helps retain moisture and suppress weeds.

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

Remove any flower stalks as they appear to prevent self-seeding; Lemon Balm can be quite aggressive and spread quickly. As the first frost approaches in early November, you can cut the plant back to a few inches above the ground. It will regrow in the spring.

You can expect your first harvest of Lemon Balm leaves starting in early June, about 70 days after planting. Harvesting can continue through early November, until the first frost. The leaves are best harvested before the plant flowers, as they have the most intense flavor at this stage.

To harvest, simply snip off the leaves with scissors or pinch them off with your fingers. Avoid taking more than one-third of the plant at a time to ensure continued production. Regular harvesting encourages new growth and keeps the plant bushy. Lemon Balm is best used fresh, as it loses much of its flavor when dried. As the first frost approaches in early November, harvest as many leaves as possible to preserve for winter use, even though they won't be quite as flavorful.

Here are a few common problems you might encounter with Lemon Balm in the Mid-Atlantic:

Aggressive Spreading

• What it looks like: Lemon Balm pops up in unexpected places, spreading beyond its designated area.
• What causes it: Lemon Balm self-seeds readily, and its roots can also spread. Our even rainfall and moderate temperatures encourage vigorous growth.
• How to fix/prevent it: Remove flower stalks before they go to seed. Consider growing Lemon Balm in a container to limit its spread. Dig up and remove unwanted plants as they appear.

Bolting

• What it looks like: The plant sends up a flower stalk prematurely. Leaves may become bitter or tough.
• What causes it: Bolting can be triggered by heat stress during our humid summers.
• How to fix/prevent it: Provide afternoon shade during the hottest part of the day. Ensure consistent moisture. Harvest regularly to encourage leaf production.

Powdery Mildew

• What it looks like: White or grayish powdery coating on leaves and stems. Leaves may curl, yellow, and die.
• What causes it: Powdery mildew thrives in warm days, cool nights, and moderate humidity, which we often experience in the Mid-Atlantic.
• How to fix/prevent it: Improve air circulation by spacing plants adequately and pruning as needed. Remove affected leaves promptly. Apply neem oil or potassium bicarbonate sprays.

Mid-Atlantic Specific Challenges: Our combination of moderate-to-hot heat, humid humidity, and even rainfall creates ideal conditions for both Lemon Balm growth and potential problems like powdery mildew. Regular monitoring and proactive measures are key to keeping your plants healthy. Also, deer pressure can be significant in some areas, so consider fencing or deer-resistant sprays if needed.

Lemon Balm is a helpful companion plant for several vegetables in the Mid-Atlantic garden.

• Tomato: Lemon Balm repels tomato hornworms and other pests that can damage tomato plants.
• Squash: It deters squash bugs and vine borers, common pests in our region.
• Broccoli and Cauliflower: Lemon Balm can help repel cabbage moths and other brassica pests.

Avoid planting Lemon Balm near any plants that require very dry soil, as its moderate watering needs might create overly moist conditions for them.