How To Grow Lemon Balm Microgreens in 5 Easy Steps

Lemon balm is a cheery herb that’s fun to use in the kitchen. Unfortunately, it’s also a very large plant that can quickly take over your garden. So, if you’re after that lovely lemon aroma without the hassle, you’ll love growing lemon balm microgreens!

Lemon balm microgreens are the same plant as lemon balm but are grown on a smaller scale. The tiny seeds are crowded together, producing a dense mat of sprouts and young leaves. This herb is ready to harvest in 24-30 days, which is a relatively long time for microgreens but a much shorter time for mature plants. Once harvested, lemon balm microgreens will add the same lemony zest to your cooking as the mature herb, but with more nutrients and less hassle to get there.

Lemon balm is well-known for making tasty and relaxing herbal tea. It’s often sipped to ease digestive issues and menstrual cramps. Because microgreens have a higher concentration of nutrients than their mature counterparts, you’ll find lemon balm microgreens teas to be just as soothing. This microgreen can also help regulate blood pressure and boost heart health. 

So, how do you grow lemon balm microgreens? Growing microgreens is easy and only requires a little patience, so let’s get into it! By the end of this article, you’ll be ready to start your own micro herb garden with a lemony twist.

What You’ll Need

Growing microgreens takes an unconventional approach. Once you have it down though, it’s pretty easy to bust out a crop of nutritious lemon balm microgreens. We’ll start with the basics of the basics: gathering materials.

You’ll be able to reuse most of these materials for other types of microgreens, so they’re well worth the investment. Here’s what you need to get started:

Seeds

Use a good quality lemon balm seed like the seed from Botanical Interests. If you’re using a 10×20 plant propagation tray, around one ounce is enough seed for one tray. Always use fresh seed for the best results.

Containers

We’re going to harvest long before the lemon balm microgreens can produce large roots. So we need a container only one to three inches deep. For a decent-sized microgreen crop, gardeners typically use 10×20″ growing trays. Each microgreen set needs one container with drainage holes and one without for the growing method we’re using.

Growing Medium

Lemon balm microgreen seeds are tiny, so we need fine-grained soil to match. We’ve found seed-starting soil to be ideal in terms of texture and water absorption. Coconut coir is another great option that’s also eco-friendly. While some microgreens can be grown hydroponically, we’ll stick with soil for our lemon balm microgreens.

Grow Lights

We strongly recommend investing in a grow light. Yes, you can cultivate lemon balm microgreens without it, but this light will make a huge difference in microgreen quality. When fixed at the correct height, the light will ensure even growth and prevent the seedlings from getting leggy. If you plan to keep up with microgreen gardening and try other types of micros, you’ll be glad to have this.

Extras

You will also need a few extras you can find around the house, like a spray bottle for misting in warmer weather, a small weight of around five pounds to hold the lid down on the cover, and a sharp knife or pair of scissors to harvest the greens when they are ready.

How to Grow

Lemon balm microgreen seeds don’t require soaking, so we can skip to planting microgreen seeds. Follow these steps for the best results:

Step 1: Plant

Start by grabbing your soil variety of choice and the tray with drainage holes. Fill the container to just under the brim and level out the soil surface. Then, mist with the spray bottle to get the soil moist but not soaking wet (the water will help the microgreen seeds stick).

Next, sprinkle your lemon balm seeds all across the soil surface. They should cover the entire tray but not overlap with each other. Spread the seed evenly so it’ll produce a dense mat of sprouts. Then, mist the soil surface with water again.

Step 2: Cover

Lemon balm often has an uneven germination rate. This isn’t a big deal when planting it in the garden, but when the seeds are crowded together and will be harvested as one, we want them as uniform as possible. That’s why we use a weighted covering and a blackout period.

The weighted cover is just your second, holeless growing tray with a small weight placed on top. Set the cover so it’s sitting directly on the microgreen seeds and blocking out all their sunlight. The weight on top will keep the seed cover in place. More importantly, though, it’ll hold down newly germinated sprouts until there are enough to lift up the lid (don’t worry, it won’t flatten them). Until that happens, the seeds will remain in their blackout germination period.

Step 3: Grow

Lemon balm seeds take 10-14 days to complete germination, so the blackout period will be at least that long. Every few days, peek under the seed cover to check that the soil is still moist, adding a gentle mist of water as needed.

Your grow light needs to be one to two feet directly above the lemon balm microgreen trays so it can light the seed evenly. Gardeners typically use wire shelving units for their setup, which allows for growing multiple microgreen crops at once. In my home, I attached the lights to the bottom of a kitchen cupboard and set the micros on the counter underneath.

Once your lemon balm microgreens have completed germination and made their first appearance, you can remove the top tray and turn on the light. Give your lemon balm microgreens at least six to eight hours of light a day. The smushed, pale sprouts will quickly transform into a cheery, tidy clump of bright green microgreen leaves. If your plants are growing leggy, move them closer to the light source. 

It will take several more days for this little herb to reach its microgreen stage. Because the lemon balm microgreens are growing so close together, we want to keep the soil surface dry while adding water to prevent mold and bacteria growth. So we’re going to grab the tray without holes and a little patience for some bottom-watering.

Fill the solid tray with an inch of water. Then, place your lemon balm microgreen tray directly inside it. The soil will absorb water through the drainage holes, keeping the roots quenched and the foliage dry. Leave the trays stacked for 10-15 minutes and then separate them (any longer, and the soil may get soaking wet!). Repeat this process whenever the soil starts to dry out. 

Step 4: Harvest

Plants have reached their microgreen stage when their cotyledons – the leaves encased in the seeds – have emerged and unfolded. When the majority of your lemon balm sprouts have reached this stage, you can start clipping them. However, because lemon balm is an herb with fully-flavored leaves, many gardeners will wait for the first few true leaves to come in before harvesting. That way, you get the cotyledons and some tiny leaves with your microgreen harvest.

It’s easy to tell when true leaves are growing in because of their shape. While lemon balm cotyledons are smooth and round, the true leaves have ridged edges and a textured surface. They also have that trademark lemony aroma that releases when you rub them.

To collect your hard-earned herb, you’ll need a sharp knife or scissors. You can take the entire microgreen gang at once or only what you need. Hold a clump of leaves in one hand and clip the stems just above the soil with the scissors. 

If you wait too long to collect your lemon balm microgreens, they’ll soon outgrow the shallow containers and demand more nutrients than the seed-starting soil has to offer. So, if you’re taking only what you need, you’ll want to start snipping as soon as those cotyledons unfold.

When you’ve collected every last microgreen, dump the spent soil into your compost bin. Reusing it for the next microgreen round is tempting, but can increase the chances of bacteria growth in such a small amount of soil. You should always use fresh soil for each microgreen planting.

Step 5: Store

Now that they’re separated from their roots and soil, we need to keep the lemon balm microgreens as fresh as possible. When it comes to vegetables, fresh equals dry, so only wash these greens right before you use them.

As mentioned earlier, lemon balm microgreens are excellent in teas. They also add a delicate yet zesty taste to cocktails, desserts, and any dish that needs a flavor boost. You could even soak these greens in your water in lieu of a lemon wedge.

Unused lemon balm microgreens should be kept dry and stored in the fridge. Wrap the microgreens in a paper towel and seal them in a food storage container. They’ll last up to seven days in the fridge, especially if you change out the paper towel as needed. 

Frequently Asked Questions