How to grow, use and propagate lemon balm 

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 to be used for cooking, herbal teas but also to attract or repel bugs and insects. 

Use lemon balm leaves fresh or dried in cold sauces, pesto, dressings or include in fillings when cooking fish, chicken or meats with healthy amounts of fat (not pork or veal).

Here today you will learn how to start lemon balm from seed as well as how to 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 important 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 a lean potting soil or opt for a soilless potting mix. Both will work just fine as long as they retain moisture while draining well.

Lemon balm plant in pot (started from seed)
Lemon balm plants will quickly outgrow any pot

2. Plant lemon balm seeds

Place seeds on soil. Avoid planting seeds in clumps. If seeds are sown too densely you will have to thin your seedling later on.  

Press seeds gently to ensure contact between seeds and soil.

Next cover 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 that the plastic is not hermetically sealed as you need air to circulate. 

If there is buildup of condensation, use a paper towel to dry the excess water and make more holes in plastic to improve air flow. 

Seeds will germinate in about 10-20 days. When you see the first leaves, remove cover to ensure good air flow and move to a spot with a minimum of 6 hours of sunlight.

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 advantages that they are mobile and it does control the herbs growth. 

Lemon balm is not invasive to the degree of, for example horseradish or peppermint. Rather the growth pattern is more like that of let’s say oregano. Create a good growing environment and the herb will not only grow, but also happily spread.

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 most any type of soil as long as it drains well. 

But with just a little bit of effort, this wonderful herb will reward you with vigorous green growth throughout the growing season.

We use compost rich, fertile and well draining soil for our lemon balm plants. As for most herbs you are looking for a slightly acidic pH between 6-7 or so. And if you do not mix your own potting soil, most regular potting soil will have you covered.

We feed our young plants a slow-release fertiliser with a NPK ratio of 10-10-10 (nitrogen, phosphorus and potassium) when they are established.

Keep soil moist but not wet and always make sure to water at the base of the plant. Never get leaves or foliage wet as it increases the risk of diseases and fungal conditions like powdery mildew to develop. 

Common pests and diseases

Lemon balm has a strong citronella smell and is known to repel unwanted pests, buffs and insects. And while lemon balm does not often fall victim to pests and diseases you could encounter problems with aphids and spider mites [1].

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 quite 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 favourite 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.

Lemon balm – being a member of the mint family – is however 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 lemon balm is left to grow free. 

Garlic and lemongrass are on the other hand 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 but is also reported to deter mosquitoes and unwanted bugs. 

Some swear by citronella oil repelling mosquitoes while others are less convinced. One field study [2] found that the use of citronella candles did not provide a significant level of protection against mosquito bites.

Still, I find that 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 will 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 stem. The plant may freeze and die back to ground level but will regrow from underground roots in the spring. 

Growing lemon balm directly in the ground, cover the plant with a thick layer of straw or mulch to insulate against the cold. 

If instead growing lemon balm in a pot or container, move the plant to an unheated but covered area and mulch to protect. 

How to harvest and store lemon balm

Use garden scissors to cut leaves of sprigs throughout the growing season. 

Wait for your lemon balm plant to reach 20 cm (8 inches) before starting to harvest leaves from the stems. 

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 and cold sauces and dressings. 

When harvesting branches or stems, cut approximately 5 cm (2 inches) from the ground, ideally just above a pair of fresh 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 mouldy before they dry. 

If you dry leaves or sprigs in the oven (or using a dehydrator), place herbs evenly in a single layer and set temperature to 35 degrees Celsius (95 degrees Fahrenheit. Leave the oven door slightly ajar and check back every now and then. Expect the drying process to last from 12 to 16 hours. Using a 

Methods to propagate lemon balm

Lemon balm can be propagated from seed but also from cuttings, layering and plant division. 

As we have already covered how to grow lemon balm from seed, this section will focus on lemon balm propagation using cuttings, layering and plant division.

Perfect size for lemon balm tip cutting
The perfect size for a tip cutting

Propagate lemon balm using tip cuttings

Cut a 10 cm (4 inches) long 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, whereas more woody stems like thyme and rosemary often do better using layering or placing cuttings directly in 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 grow. 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 to grow unchecked and this growth will come from a root system continuously growing horizontal roots that sprout new shoots with fresh growth.

When we propagate using root cuttings, we simply dig out stems with roots and all, starting from the outside of the plant.

When the horizontal roots are exposed, simply cut to create several single stem plants to plant in pots around your garden. 

Lemon balm propagation by layering 

Propagation by layering is a method where you bury parts of a branch in soil causing the plant to grow new roots along the buried branch and then cutting the branch to free it from the base plants.

This new layered cutting can now be used to start a new plant. 

When layering it is important to remove leaves from the part of the stem that will be buried. 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 quite 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 4 new plants. 

For us, April or August are ideal times of the year to propagate lemon balm by plant division.

Do not get too greedy when dividing your plant. Make sure that each new plant has a healthy root system that will sustain new growth.

And always prepare the new sites for planting before dividing the plant. Make sure you minimise the time the root system is exposed to air. 

5 best uses of lemon balm

We use fresh lemon balm throughout the growing season and then 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 favourites.

2. Thinly sliced in salads

Pick fresh lemon balm leaves from the top third of your plant. Gently roll the leaves tightly without bruising the leaves. 

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

Pesto does not always  have to be made with basil and pine nuts. Live a little and mix it up.

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 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 up 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 you are 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 simply use it to flavor green salads, bruschetta as well as pasta and couscous based salads and dishes.

Helpful resources:

[1] https://www.herbsociety.org/file_download/inline/d7d790e9-c19e-4a40-93b0-8f4b45a644f1

[2] https://malariajournal.biomedcentral.com/articles/10.1186/1475-2875-10-S1-S11#:~:text=Citronella%20and%20geraniol%20candles%20are,bites%20%5B37%E2%80%9339%5D.

Meet the author: Mattias is an experienced gardener spending most of his free time on his knees among herbs, plants and garden vegetables. For the past two years he has been sharing gardening projects and how-to tutorials on the NordicLavender website and YouTube channel.