Lemon balm is an easy-to-grow herb that often is overlooked by home gardeners. And it is a shame as gardeners of all levels can propagate lemon balm from both seeds and cuttings.
Lemon balm is a versatile herb used for cooking and herbal teas but it also attracts or repels bugs and insects.
Use lemon balm leaves fresh or dried in cold sauces, pesto, and dressings, or include them in fillings when cooking fish, chicken, or meats with healthy amounts of fat (not ideal with pork or veal).
Today you will learn how to start lemon balm from seed and propagate lemon balm via layering, cuttings, and plant division.
Just the facts on starting, growing and propagating lemon balm: 1. Start from seed indoors in April / May 2. Use lean potting soil mix, plant seeds on surface, cover lightly 3. Mist seeds and cover with plastic wrap 4. Keep seeds moist but not wet 5. Transplant outdoors when seedlings are 10 cm (4 inches) tall, 25 cm (10 inches) apart 6. Propagate by tip cuttings, root cuttings, layering or plant division
How to start lemon balm from seed
Lemon balm is suitable for all levels of gardeners starting from beginners. But as always, it is essential to pay attention to the details.
1. Select pots and your preferred potting soil (or soilless potting mix)
Start seeds in seed starting trays or use starter pots. Seed starting trays often come with plastic domes, but you can also use plastic wrap.
Make sure you use lean potting soil or a soilless potting mix. Both will work fine as long as they retain moisture while draining well.
2. Plant lemon balm seeds
Place seeds on the soil. Avoid planting seeds in clumps. If you sow the seeds too densely, you will have to thin the seedlings later.
Press seeds gently to ensure contact between the seeds and the soil.
Next, cover the seeds with a light sprinkling of soil or vermiculite.
3. Mist seeds and keep moist
Use a spray bottle to mist seeds until moist. Now cover with plastic. Make sure the plastic is not hermetically sealed, as you need air to circulate.
If there is a condensation buildup, use a paper towel to dry the excess water and make more holes in the plastic to improve airflow.
4. Transplant seedlings
When seedlings are 10 cm (4 inches) tall, they are ready to be transplanted.
Transplant to an in-ground herb garden when there is no longer any risk of frost, or choose a suitable pot, container, or grow bag.
Lemon balm plants grow well in pots, containers, and grow bags with the added advantage of being mobile and controlling the herb’s growth.
Lemon balm is not invasive to the degree of, for example, horseradish or peppermint. Instead, the growth pattern is more like that of, let’s say, oregano. Create an excellent growing environment, and the herb will spread happily.
If planting directly in the ground, choose a location that offers full sun to half shade and some relief from the sun during the hottest parts of the day.
5. Care for lemon balm plant
Lemon balm plants are not fussy and will tolerate almost any type of soil as long as it drains well.
But with just a little effort, this wonderful herb will reward you with vigorous green growth throughout the growing season.
Our lemon balm plants grow in compost-rich, fertile, and well-draining soil. As for most herbs, you are looking for a slightly acidic pH between 6 and 7. And if you do not mix your potting soil, most regular potting soil will have you covered.
When established, we feed our young plants a slow-release fertilizer with an NPK ratio of 10-10-10 (nitrogen, phosphorus, and potassium).
Keep the soil moist but not wet, and always water at the base of the plant. Never get leaves or foliage wet, as it increases the risk of developing diseases and fungal conditions like powdery mildew.
Common pests and diseases
Lemon balm has a strong citronella smell and is known to repel unwanted pests, buffs, and insects. Lemon balm does not often fall victim to pests and diseases, but you could encounter problems with aphids and spider mites .
Here the best treatment is to spray the plant using a garden hose. You can also use a Neem oil solution, but as lemon balm plants are pretty sturdy, we recommend you start by simply spraying the plant with water.
Lemon balm as a companion plant
Lemon balm is alongside lemongrass and garlic, our favorite companion plant in that it deters pests and diseases. We grow lemon balm close to our raised garden beds with lettuce, corn salad, chard, and kale and rarely experience problems with pests.
However, lemon balm – a member of the mint family – is a bit invasive why we do not plant it in our garden beds. Lemon balm is fast-growing, and herbs like sage, oregano, thyme, rosemary, parsley, chives, and tarragon will suffer if the lemon balm grows unrestricted.
On the other hand, garlic and lemongrass are ideal companion plants to plant and grow inside raised garden beds if you have the space.
Which bugs will lemon balm deter?
Lemon balm is a great companion plant for herbs and plants and is even reported to deter mosquitoes and unwanted bugs.
Some swear by citronella oil repelling mosquitoes, while others are less convinced. One field study  found that using citronella candles did not provide significant protection against mosquito bites.
Still, I find it helps to rub fresh lemon balm leaves against exposed skin when spending time in the garden. But tread carefully, as some people can experience adverse effects when exposed to citronella oils.
Lemon balm flowers attract pollinators
Lemon balm will attract bees, butterflies, and other beneficial insects and pollinators when left to flower.
The tiny flowers appear throughout the summer and are often white or shades of yellow, pink, purple, or blue.
Lemon balm will flower and self-seed for me in zone 7 when given full sun exposure. In warmer climates, lemon balm does however prefer light shade.
How to overwinter lemon balm plants
Lemon balm is a hardy perennial and will overwinter in growing zones 4-9. Still, it is easier to successfully overwinter lemon balm plants in pots and containers than when plants are grown directly in the ground.
Cut back plant late fall leaving only about 5 cm (2 inches) of the stem. The plant may freeze and die back to ground level but will regrow from underground roots in the spring.
Cover the plant with a thick layer of straw or mulch to insulate against the cold if you grow lemon balm directly in the ground.
If you prefer to grow lemon balm in a pot or container, move the plant to an unheated but covered area and mulch to protect it.
How to harvest and store lemon balm
Use garden scissors to cut the leaves or sprigs throughout the growing season.
You will find that older, more mature leaves are stronger-tasting, while fresher new top growth is more suitable to be thinly sliced for salads, cold sauces, and dressings.
When harvesting branches or stems, cut approximately 5 cm (2 inches) from the ground, ideally just above a pair of new leaf nodes.
Dry leaves in the oven or using a dehydrator. Stems or sprigs of lemon balm can be tied together and hung to dry in a place with good air circulation.
Do not tie too many branches together, as you need air to flow freely between the leaves. And make sure the herbs are dry before you hang them. Wet herbs will go moldy before they dry.
When drying leaves or sprigs in the oven (or using a dehydrator), place herbs evenly in a single layer and set the temperature to 35 degrees Celsius (95 degrees Fahrenheit). Leave the oven door slightly ajar and check back now and then. Expect the drying process to last from 12 to 16 hours.
Methods to propagate lemon balm
You can propagate lemon balm from seed, cuttings, layering, and plant division.
We have already covered how to grow lemon balm from seed, why this section will focus on lemon balm propagation using cuttings, layering, and plant division.
Propagate lemon balm using tip cuttings
Cut a 10 cm (4 inches) tip from your lemon balm plant. Gently remove most leaves from the cutting leaving only 1 or 2 pairs of leaves.
Generally speaking, softwood cuttings like basil and sage will propagate in water. In contrast, more woody stems like thyme and rosemary often do better when layering or placing the cuttings directly in the soil.
We find that lemon balm almost falls in the middle. Still, we prefer to place tip cuttings in water. New roots will grow from the nodes where the leaves used to develop. Expect new roots to grow in 2-4 weeks.
If you prefer propagating in soil, follow the steps above bur instead make a hole in your soil and insert the cutting. Leave about half the length of the cutting above the soil.
Propagate lemon balm using root cuttings
Lemon balm will spread if left unchecked, and this growth will come from a root system growing horizontal roots that sprout new shoots with fresh growth.
When propagating using root cuttings, we dig out stems with roots, starting from outside the plant.
When the horizontal roots are exposed, cut them to create several single-stem plants in pots around your garden.
Lemon balm propagation by layering
Propagation by layering is where you bury parts of a branch in the soil, causing the plant to grow new roots along the buried branch, and then cut the stem to free it from the base plants.
This new layered cutting can now be used to start a new plant.
When layering, it is essential to remove leaves from the buried stem. Ideally, use string or wire to help the branch stay buried.
Also, using a knife to score the buried part of the branch will help stimulate new root growth.
The process is effective and relatively easy when you get the hang of it.
Still, we find it easier to propagate by cuttings or plant division.
Lemon balm propagation by plant division
A mature and established lemon balm plant can easily be divided into as many as four new plants.
For us, April or August are ideal times to propagate lemon balm by plant division.
Do not get too greedy when dividing your plant. Ensure each new plant has a healthy root system to sustain further growth.
And always prepare the new sites for planting before dividing the plant. Make sure you minimize the time you expose the root system to air.
5 best uses of lemon balm
We use fresh lemon balm throughout the growing season and frozen or dried lemon balm for the rest of the year.
Here are our top 5 uses of lemon balm in no particular order.
1. Lemon balm-infused iced tea
So simple and yet so refreshing. Add fresh lemon balm leaves to hot water and leave to infuse.
When you are happy with the taste, leave it to cool.
Add crushed ice and your preferred sweetener to taste. Stevia and honey are our two favorites.
2. Thinly sliced in salads
Pick fresh lemon balm leaves from the top third of your plant. Gently roll the leaves tightly without bruising them.
Next, thinly slice the leaves using your sharpest knife. Do not chop.
Mix into your green salad for a fresh zing that is hard to beat.
3. Pesto made with lemon balm and almonds
Next time, replace basil and pine nuts with lemon balm and almonds for a taste that I bet will be a new favorite.
4. Grow next to vegetables to deter pests
Lemon balm is a member of the Lamiaceae or mint family and has that streak of being a vigorous close to an invasive grower.
Plant your lemon balm in pots, grow bags, and containers to be placed where you need a helping hand to deter unwanted bugs and pests.
5. Lemon balm-infused vinegar
Heat your vinegar but do not let it go to boil. Add leaves or even sprigs of lemon balm to your vinegar and seal the container tightly.
Wait for about a week, then taste and decide whether the vinegar needs more time to absorb the flavor.
When happy with the flavor, use a sieve to strain the leaves.
Use the deliciously lemon balm-infused vinegar as a base for salad dressings or flavor green salads, bruschetta, pasta, and couscous-based salads and dishes.