How to Grow Lemon Balm Indoors
The Spruce / Krystal Slagle
Lemon balm is an ancient herb native to southern Europe that is closely related to mint. It features similar wrinkled, oval-shaped leaves and boasts a fresh citrusy smell and scent that many home cooks love to add to salads, soups, and more. Lemon balm also has a unique medicinal history—its use as a curative can be traced back to ancient Greece and Rome, where its leaves were used in a variety of tonics and teas, and its essential oils were extracted to aid with digestive issues.
The versatile herb is a rapid grower outdoors—after planting in early spring, it’s not unusual to see a lemon balm plant grow to over a foot tall (sometimes, even two!) in just a single season. For that reason, many gardeners choose to plant lemon balm in containers, whether grown indoors or out, in an attempt to control its invasive nature. Like many other herbs, lemon balm prospers best outdoors but can be grown successfully inside as well, as long as proper attention is paid to its unique needs.
|Botanical name||Melissa officinalis|
|Common name||Lemon balm|
|Plant type||Herbaceous perennial|
|Mature size||1.5–2 ft. tall, 1.5–3 ft. wide|
|Sun exposure||Full sun, partial shade|
|Soil pH||Neutral to acidic|
|Flower color||White, pale yellow|
|Hardiness zones||3–7 (USDA)|
Lemon Balm Care
A hardy perennial shrub that is tolerant to USDA zones 3 through 7, lemon balm can be grown year-round indoors, as well as outdoors in warmer climates. Even if you’re seasoned at growing lemon balm outdoors, there are several things you’ll need to modify slightly in order to successfully grow it in your home. Lemon balm will need significantly more sunlight when planted indoors and can be more susceptible to afflictions like powdery mildew and root rot, not to mention browning leaves, which can indicate issues like cold air or excessive sunlight.
Lemon balm also has the tendency to bolt if exposed to too much water or not maintained properly. If you notice small flower buds beginning to form on your lemon balm plant, take care to pinch them off quickly. Once the plant blooms, the flavor of its leaves will change, causing them to taste bitter. To cook with your lemon balm, harvest the leaves as soon as the plant is established and putting out regular new growth. Take care to never remove more than about 25 percent of the plant’s mass at any one time.
In both indoor and outdoor environments, lemon balm loves a sunny spot. However, unlike an outdoor lemon balm plant—which can tolerate a bit of shade—those planted indoors need ample sunlight, at least five to six hours a day. Place your herb containers near a windowsill that gets ample light throughout the day. If you notice your plant getting a lot of harsh direct rays or turning brown on its leaves, rotate it periodically to avoid burning.
Lemon balm plants prefer a slightly sandy, well-drained soil. Most basic potting soils will work just fine, but if you find your mixture is a bit dense or stays too moist between watering, combine it with sand or a drier soil varietal like a cactus mix. Additionally, the pH of your soil should be neutral to acidic, with a specific level between 6.7 to 7.3 providing the best environment. When selecting a container to house your lemon balm plant in, choose a pot with ample drainage holes to minimize the risk of the herb becoming waterlogged or the roots rotting. One made of clay or terracotta can also be helpful, as the porous material will help to wick any added moisture from the soil.
When it comes to watering your lemon balm plant, always err on the side of under-watering, rather than over-watering. The reason: Like many herbs, lemon balm plants can recover easily from wilt (created by thirst) but will quickly die or bolt if watered too much. Your exact watering schedule will depend on the environment in your home and the plant’s sun exposure levels, but a good general rule of thumb is to water in small quantities (do not saturate) as soon as the first inch or so of soil in the pot has dried up.
Temperature and Humidity
When it comes to its indoor environment, the lemon balm plant is not particularly picky. In general, it’s best to keep your herb away from any drafty air that is too cold or too hot, such as in front of an air conditioner or next to a radiator. Additionally, lemon balm does not need a humid environment to thrive, so you won’t have to worry about increasing the moisture levels in the air with a humidifier.
While lemon balm does not require additional feeding beyond what nutrition its soil provides, you can treat it with a light liquid fertilizer every few weeks to encourage growth. Keep in mind, fertilizing some herbs has been known to decrease the potency of their scent and/or flavor—if you’re growing lemon balm specifically for cooking, you can likely skip fertilizing it and still be just fine.
Propagating Lemon Balm
Lemon balm is what’s known as a self-seeding plant, meaning outdoors it spreads its seeds to further its growth (hence why some gardeners consider it invasive). However, most indoor growers won’t see their plants set seeds. Instead, it’s advised to discard your lemon balm plant if it bolts (goes to flower), in part because the taste and potency of the leaves will be diminished. It’s easy to start new plants from packaged seeds (they will germinate in a little over a week) or simply buy new seedlings at your local garden center.
How to Grow Lemon Balm From Seed
Lemon balm seeds need ample light in order to germinate and grow. To start your plant from seed, begin them in a shallow pot or dish, barely covering the seeds with more than a sprinkle of soil (this should be done about six to eight weeks before the last frost if you want to transplant the herb outdoors). Expose the dish to ample light and just enough water to keep them from drying out (its helpful to use a spray bottle instead of a watering can for this stage) and germination should take place in 10–14 days. Once the seedlings are large enough to handle easily, you can transplant them into a traditional pot with soil.
Lemon balm has no serious pest issues, but can be susceptible to powdery mildew. To prevent it from developing, plant your lemon balm with ample room separating it from other plants to allow for good air circulation. If powdery mildew does develop, remove the infected leaves, and treat with a mild fungicide.
Successfully grow lemon balm indoors with tips for germinating from seed, maintaining the proper conditions, and harvesting.
How to Grow, Harvest and Use Lemon Balm
By Jill Henderson
I always get excited when I talk about herbs, especially when I talk about medicinal culinary herbs like lemon balm. Lemon balm’s simplicity, beauty, flavor, ease of care, and exceptional medicinal properties make it one of my favorites.
I particularly like the way lemon balm attracts beneficial insects and butterflies to my garden, and occasionally even the hummingbirds find it intriguing.
I am also partial to lemon balm tea, especially on a cold winter night, when its deep, earthy, lemony flavor brings back a touch of summer sunshine.
Sometimes referred to as Melissa or Sweet Melissa, Lemon Balm (Melissa officinalis) is a member of the Lamiaceae, or mint family, of plants. Like other mint family members, lemon balm has scalloped, oval- to heart-shaped leaves that grow opposite one another on square (four-sided) stems. Its leaves are bright green on top and whitish below.
Lemon balm is a great herb to share with kids because the leaves are wonderfully fuzzy to touch, and they leave a trace of lemon scent on the fingers. Most people don’t stop to look at the flowers of lemon balm because they are very small. Up close, the tiny white to pale pink two-lipped flowers form whorled spikes that are quite pretty.
Harvesting the long stems of lemon balm.
Lemon balm is one of those herbs that isn’t thought of all that much beyond tea. But in reality, this sometimes rambling and invasive “mint” has played a crucial role in the health and well-being of humans and animals alike for thousands of years. It’s easy to grow, looks nice, and smells and tastes even better! If you have a little room to spare in the yard or garden, you might want to give this little herbal gem a try.
How to Grow Lemon Balm
Depending on the type of soil you want to build and amount of sunlight, this spreading perennial herb can reach heights of 1 to 3 feet with an equal spread. Like mint, lemon balm is quite hardy and can be overwintered as far north as hardiness zones 4 and 5.
It is always a good idea to mulch plants year-round, but winter mulch is of the utmost importance. Mulch helps keep the ground frozen in areas where the ground freezes and keeps it warmer in areas where it doesn’t. Mulch also helps prevent the plant from being heaved out of the ground in times of repeated freeze and thaw cycles. Lemon balm will grow almost anywhere in the garden and isn’t particularly fussy about the quality of soil it grows in.
In general, your plant will be larger and more productive when grown in full sun and fertile, loamy soil. In regions with very hot or dry summers, lemon balm appreciates a bit of afternoon shade and soils that retain moisture. If you plant lemon balm in soil that is both very fertile and loamy, it will spread like wildfire throughout your garden. We have a lot of red clay soil here in the Ozarks, and I find that my lemon balm not only grows well, but that it also stays relatively close to where I plant it. And while lemon balm prefers moist soil, healthy and mature plants easily endure extended periods of heat and drought.
Like most mint family members, lemon balm is easily started from seed. For outdoor culture, seed can be sown either in mid-spring after all danger of frost has passed or in early fall to late winter.
While both are good, I personally feel that winter sowing has advantages over spring sowing. Winter-sown seeds have a feel for the seasons and germinate only when the weather is optimal. They also have higher germination rates, and their seedlings are hardier and grow more vigorously than those sown indoors. But best of all, winter-sown seeds don’t take up any room in the house or require artificial heat or light.
To start lemon balm indoors, sow seeds six to eight weeks before the last frost. Start with small pots filled with a light seed-starting mix and barely cover.
I prefer to sprinkle seeds on the surface of the soil and then lightly scratch them in before watering. Seeds take seven to fourteen days to germinate at 70°F, but longer if indoor temperatures are cooler.
Once seedlings have their second set of true leaves, either thin them to one or two per pot or repot individual seedlings into larger containers. After all danger of frost has passed, seedlings should be set in the garden 12 to 18 inches apart.
Although sowing seed has its advantages, there is one crucial drawback that most gardeners are not aware of. As is the case with many herbs, each lemon balm plant that is grown from seed will be slightly different. They will generally look alike, but they may not smell or taste the same. This is why I highly recommend starting lemon balm from established plants, be it rooted stem cuttings, root divisions, or seedlings from a nursery. This way, you can smell and taste the leaves before investing a lot of time and money into a plant that has an inferior smell and taste.
Be sure to leave ample space between lemon balm and nearby plants, as it has a penchant for sprawling and crawling.
To keep plants tidy and within bounds, pinch or cut the stem tips back regularly throughout the growing season. And to prevent scraggly or spindly growth, divide mature plants every three to five years.
How to Harvest Lemon Balm
Many gardeners like the idea of planting an herb garden, but aren’t always sure what to do with the herbs once they are mature. You can harvest handfuls of lemon balm leaves for fresh use almost any time during the growing season. For a large harvest of leaves that will be dried for tea or medicinal use, it is preferable to wait until the plant begins to put on flower buds or just as the flowers begin to open. This is when the volatile oils in the leaves are at their greatest concentration.
When you are ready, cut each stem just above a pair of leaves using a very sharp pair of scissors or pruning shears. You can cut the plant down to within six to eight inches of the soil. A good rule of thumb is to remove no more than two-thirds of the vegetative growth at any one time. Finish the job by pruning stray stems and shaping so the plant looks tidy, and then water it deeply.
A second harvest may be possible in the fall if the plant is healthy and has regenerated many new leaves, but the first harvest is always the sweetest and most fragrant.
How to Dry & Store Lemon Balm
Once you have your basket full of cut stems, you will need to process them for drying. There are many ways to dry herbs, all of which are a bit tedious, depending on where you live and how you approach it. Drying is the only way to preserve the quality and flavor of lemon balm for long-term storage, though.
Over the years, my husband, Dean, and I tried many methods of drying herbs until we finally found one that suited our schedule and our taste buds.
The author dries lemon balm in stainless steel metal baking pans.
We start by stripping the leaves from the stems. Yes, this can be a bit monotonous, but trust me: it saves a lot of time later on and your leaves don’t get crushed in the process.
To strips the leaves quickly (relatively speaking) we ‘zip’ the leaves off with our fingers. To do this, start by holding the tip (top) of the stem firmly between your left thumb, index, and ring fingers. With the same three fingers of your right hand, pull firmly downwards along the stem.
This zipping technique quickly pulls off all leaves and branching stems in one fell swoop. Repeat the ‘zipping’ with all stems until all leaves have been removed.
At this juncture, tradition has it that you should use a dehydrator to dry your herbs, or that you should spread the leaves on screens or hang them in bunches and dry them in a cool dark place. The problem I have with these methods are: a) I don’t have a dehydrator, nor do I want one; b) a dehydrator can’t possibly hold the quantity of leaves we process each year; and c) my climate is too humid to properly dry leaves in a “cool dark place.”
When I lived in the drier areas of the north and northwest United States, drying herbs was a snap, even in the shade. Here in Missouri, though, summers can be unbelievably humid. Because of this, I have come to rely on a very unconventional drying method.
After some disappointing attempts at drying basil and sage (two of the trickiest herbs to dry properly) the traditional way, my husband suggested we try a different approach. He had noticed how some of the leaves from the “zipping” process that we had left on the concrete walkway dried up extremely quickly. He proposed that the rest of our herbs would dry there just as quickly.
After so many trials and mediocre results, I was game for anything. We laid our stripped leaves in a single layer on shiny stainless steel baking pans, which we then set on the concrete walk in the sun. Most often the herbs dried in one day — in some cases within hours. In every batch, the herbs came out vibrantly green and extremely fragrant.
Let it be known that I fully understand that the standard rule for drying herbs is to never (ever) dry them in the sun. The theory is that prolonged exposure to high heat and bright light can evaporate the delicate volatile oils that make herbs flavorful and medicinal. I hated to ignore the herbalist in my head, but the method worked so beautifully that, 15 years later, I can’t even imagine doing it any other way.
In order to clear my conscience, I placed two different thermometers in the pan to see how hot the herbs — and the pan — actually got during the course of the day. The pans were placed in full sun on a 92°F (33°C) day and only reached 130°F (54°C), which is absolutely acceptable in terms of drying temperatures for herbs.
To retain maximum medicinal value in the leaves, the temperature should have been a little lower, but that can be easily achieved by choosing a cooler day or by placing the pan in dappled shade. If you decide to try this method, it is very important to monitor the herbs in the pan just as you would if you had a cake in the oven. Use a meat thermometer to gauge the temperature, stir the herbs often, move them into the shade when they start to get crisp, and always allow the herbs to cool completely before storing.
When the leaves crumble to pieces when pressed, they are ready to store in airtight jars or plastic bags in a cool, dark place. Keep in mind that whole herbs retain their flavor and medicinal properties longer than those that are crushed or ground.
How to Use Lemon Balm
The smell and taste of common lemon balm is not as sharp or crisp as a lemon, but is rich, deep, and woody, especially when dried. Newer cultivars have an improved lemony aroma. Lemon balm is wonderful when used to make hot or cold tea, and its flavor blends very well with black tea and other herbs such as apple mint, lemon verbena, anise, fennel, and fenugreek. The leaves and flowers make unique, flavorful jelly or herbed vinegar. They can also be added to creamy dressings, dips, and spreads. Add young leaves to fruit punch and green or fruit salads.
One of my favorite things to make with lemon balm is shortbread or sugar cookies. Simply pick out your favorite generic recipe and add to it a handful of fresh, chopped lemon balm leaves and a few toasted nuts.
Although there are many great ways to use lemon balm in the kitchen, the real magic of this sometimes-beguiled herb lies in its medicinal properties. And make no mistake about it: lemon balm is a powerful and useful medicinal.
To begin with, lemon balm is a super-strong anti-inflammatory and gentle sedative that can help relieve mild insomnia, depression, and tension. Herbalists also recommend it to treat infection and inflammation of the upper respiratory tract and to reduce symptoms of cold and flu. It is especially effective at soothing indigestion, heartburn, and stomachaches. When taken orally, lemon balm has similar actions to nonsteroidal anti-inflammatories such as aspirin, ibuprofen, and naproxen, without these drugs’ dangerous long-term side effects.
Lemon balm also contains constituents that fight all kinds of viral infections, and it is one of the very best treatments I have ever found for the treatment of cold sores. In fact, scientific studies have proven that internal and topical application of lemon balm reduces the severity, duration, pain, and recurrence of cold sores, mouth ulcers, and other viral eruptions like shingles, which are all caused by the herpes virus.
For many years, I was plagued by repeated outbreaks of large, painful cold sores on my lips and around my mouth. On two occasions, cold sores on my mouth were infected by Streptococcus bacteria and resulted in impetigo, a very serious and contagious skin infection.
By applying a strong infusion of lemon balm to the affected area at the earliest onset of symptoms, and by consuming up to three cups of lemon balm tea every day for the duration of the outbreak, I was able to rid myself of both the cold sores and the severe case of impetigo. Within a few months of using lemon balm to treat recurring outbreaks, the herpes simplex virus literally went dormant. And thanks to lemon balm, I have had no more than a half dozen cold sores in over 15 years. The few that I did get were relatively small and short-lived.
In addition to reducing the severity of cold sores, lemon balm also appears to speed healing and to reduce or inhibit secondary infections. Externally, it can be used to treat rashes, hives, insect bites, swelling, and minor wounds. Researchers are reportedly even using extracts of lemon balm to try to treat mild Alzheimer’s disease.
Although it has been suggested that lemon balm may support normal function of the thyroid gland, anyone with hypothyroidism (low thyroid function), goiter, Hashimoto’s disease, or those taking any kind of thyroid hormone such as anti-cholinergics or cholinergics should not take lemon balm in medicinal doses without first consulting a professional.
Lemon balm is an exceptionally attractive herb that lights up any garden path. And while the flowers are not excessively showy and can at times give the plant a leggy or ragged appearance, they attract many beneficial insects to the garden. Lemon balm is not only a fragrant and flavorful culinary herb, but also a powerful medicinal that deserves a spot in every garden. If nothing else, the simple beauty of its soft, sculpted leaves and pleasant smell will do much to cheer up any gardener.
This article appeared in the February 2014 issue of Acres U.S.A.
Jill Henderson is an artist, author and organic gardener. She is currently the editor of Show Me Oz, a blog featuring articles on gardening, seed saving, nature ecology, wild edible and medicinal plants, and culinary herbs. She has written three books: The Healing Power of Kitchen Herbs, A Journey of Seasons: A Year in the Ozarks High Country, and The Garden Seed Saving Guide.
Lemon balm is not only a fragrant and flavorful culinary herb, but also a powerful medicinal that deserves a spot in every garden.