Lemon balm, a perennial herb of the mint family, is an ideal plant for gardeners of all skill levels because it is hardy, easy to care for and has many benefits. It has a wonderful aroma, attracts pollinators and can be harvested heavily throughout its growing season. The plant can tolerate a wide range of climates, making it easy to grow in just about any location.
Preparation and Planting
Lemon balm can be grown from seed or cuttings. Seeds are more easily obtained, but if your lemon balm-growing neighbors don't mind sharing, the cuttings will result in a more quickly established plant once placed in the ground.
Start seeds indoors about 8 to 10 weeks before the last frost date in your area. The germinating seeds need a lot of light, so sprinkle soil over them lightly and provide at least 5 to 6 hours of light a day. You can use artificial light if you don't have a sunny window sill to place them on. Be sure the soil is kept moist. The seedlings should emerge in about 8 to 10 days.
If you have cuttings, simply place them in water and wait for roots to appear.
Once the danger of frost has passed, the seedlings or cuttings are ready to be transplanted outside. Lemon balm prefers moist soil with a pH of between 5.0 and 7.5. Partial shade is preferred, but the plant can also endure full sun or shade, allowing it to grow in most locations. Plant cuttings or seedlings 12 to 24 inches apart. These plants have shallow roots, so add a layer of insulating mulch to protect them from extreme temperatures.
If you don't have garden space or want that lemony aroma in your home all year long, you can grow lemon balm indoors. Select a 4 to 5 inch container because potted lemon balm grows better when it is crowded. Make sure the plant gets plenty of light and that the soil stays damp.
Lemon balm thrives in moist, well-drained soil. It is important to keep the soil from drying out but take care not to over-water. Root rot and powdery mildew have been known to affect plants that get too much water. A drip system or soaker hose will help keep the soil moist in summer. Check the plants daily to be sure they are getting an adequate water supply. The mulch you used should help keep it damp as well.
The mulch should also keep weeds down. However, if you do see weeds, it is important to eradicate them immediately. Remove them by hand, taking care not to disrupt the plant's shallow roots.
To ensure fresh, fragrant leaves throughout the growing season, prune the plant close to the ground regularly. It will grow back quickly and give you a higher yield. For a bushier plant (and more leaves for harvesting), pinch back some of the growing tips at least twice during the growing season.
To help maintain good growth, you should also apply an all-purpose fertilizer once in spring and once in fall. Be careful not to over-fertilize as this will produce less flavorful leaves.
Harvesting and Drying
Harvesting often is key with lemon balm. This will keep the plant from overtaking your garden and will produce the best-tasting, more fragrant leaves.
Young leaves can be harvested at any time during the growing season. This is best done by clipping the leaves in the morning. Fresh leaves must be handled carefully to avoid bruising and discoloration.
To harvest for drying, cut the stems within a few inches of the base of the plant just as it comes into bloom. Tie them into groups of 5 or 6 and hang them in a warm, airy location. The leaves will turn brown if exposed to moisture, so it is best to do this indoors. When dry, strip off the leaves, store in an airtight container and use as needed.