Lemon Balm in Zone 6B — Midwest

Lemon Balm is a fantastic herb to have in your Midwest garden. The lemony flavor is wonderful in teas, salads, and even desserts, and it's incredibly easy to grow in our fertile soil. Plus, the bees absolutely love it, making it a great addition to any pollinator garden.

Our Midwest weather can be unpredictable, with late frosts and summer heat spells. But don't worry, Lemon Balm is quite hardy, and with a bit of planning, you can easily enjoy a bountiful harvest within our 183-day growing season.

Starting Lemon Balm indoors isn't essential, but it can give you a head start, especially if you're eager for an early harvest. Sow seeds indoors from late February through mid March, about six weeks before you plan to transplant them outside. Use seed trays with a good seed-starting mix, keep them warm, and provide plenty of light – a simple grow light works wonders.

Bottom watering is a great way to keep the soil consistently moist without overwatering. Just set the tray in a shallow dish of water and let the soil soak it up from the bottom. Given our moderate-to-late springs here in the Midwest, starting indoors can ensure you get a jump on the season.

Transplant your Lemon Balm seedlings outdoors from mid April through mid May, once the danger of frost has passed. Before transplanting, be sure to harden off your seedlings by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the sun and wind.

Space your Lemon Balm plants about 18-24 inches apart to give them plenty of room to grow. Keep an eye on the weather forecast – those unexpected late frosts can still sneak up on us here in the Midwest, so be ready 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. Sow seeds directly into your garden from mid April through late July. The soil should be at least 60°F for best germination.

Prepare the soil by loosening it and removing any weeds. Sow the seeds shallowly and keep the soil consistently moist. Direct sowing is less work than starting indoors, but you'll need to be patient as the plants establish themselves. Just be sure to thin the seedlings to 18-24 inches apart once they're a few inches tall.

Lemon Balm prefers moderate watering, which fits well with our typical Midwest summer. While it's not drought-tolerant, it also doesn't like to sit in soggy soil. Pay attention to the weather and adjust your watering accordingly.

During our moderate-to-hot summer heat spells, check the soil moisture regularly using the "finger test" – stick your finger about two inches deep into the soil. If it feels dry, it's time to water. Aim for about an inch of water per week, either from rainfall or irrigation. Given our moderate-to-humid conditions, it's best to water at the base of the plant to avoid creating overly humid conditions around the leaves.

Signs of underwatering include wilting leaves and slow growth. Overwatering can lead to yellowing leaves and root rot. Mulching around your Lemon Balm plants with straw or wood chips helps retain moisture and keeps the soil cool.

Pruning Lemon Balm is simple and keeps it looking its best. In midsummer, cut the plant back by about half to prevent it from becoming leggy and to encourage bushier growth. This also helps to keep it from taking over your garden.

Be sure to remove any flower stalks as soon as you see them. Lemon Balm is an aggressive self-seeder, and removing the flowers prevents it from spreading too much. As our first frost approaches around mid- October, you can give your Lemon Balm a final trim before winter.

You can expect your first harvest of Lemon Balm leaves from late June through late October. The leaves have the best flavor before the plant flowers, so keep an eye on those flower stalks! Harvest leaves as needed, snipping them off with scissors or pruning shears.

When harvesting, avoid taking more than a third of the plant at any one time to ensure continued production. Regular harvesting encourages the plant to produce new growth, so don't be shy! As the first frost approaches here in the Midwest, harvest any remaining leaves to dry or freeze for later use.

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

Aggressive Spreading

• What it looks like: Lemon Balm popping up in unexpected places throughout your garden.
• What causes it: Lemon Balm is an enthusiastic self-seeder, and seeds can spread easily.
• How to fix/prevent it: Remove flower stalks before they go to seed. Consider growing Lemon Balm in a container to limit its spread. You can also dig up and divide the plant every few years to keep it under control.

Bolting

• What it looks like: The plant sends up a flower stalk prematurely, and the leaves become bitter or tough.
• What causes it: Bolting can be triggered by heat stress, especially during our Midwest summer heat spells.
• How to fix/prevent it: Provide some afternoon shade during the hottest part of the day. Keep the soil consistently moist. Harvest leaves frequently to encourage new growth and delay bolting.

Powdery Mildew

• What it looks like: A white or grayish powdery coating on the leaves and stems.
• What causes it: Powdery mildew thrives in warm days, cool nights, and moderate humidity – conditions we often experience in the Midwest.
• How to fix/prevent it: Improve air circulation by spacing plants adequately and pruning as needed. Remove affected leaves promptly. A milk spray (1 part milk to 9 parts water) can be surprisingly effective.

Midwest Specific Challenges: Our moderate-to-hot heat and moderate-to-humid conditions can encourage powdery mildew and bolting. The wet-summer rainfall can also contribute to overly moist soil, so be sure to provide good drainage.

Lemon Balm makes a great companion plant for several vegetables in your Midwest garden. It's said to repel certain pests and attract beneficial insects.

Good companions include:

• Tomato: Lemon Balm can help deter tomato hornworms and other pests that attack tomatoes.
• Squash: It can help repel squash bugs and vine borers.
• Broccoli and Cauliflower: The scent of Lemon Balm can deter cabbage moths and other pests that target these brassicas.

Avoid planting Lemon Balm near rue, as they are said to inhibit each other's growth.