Lemon Balm: Grow This Calming Herb on Your Windowsill
Clinical trials confirm lemon balm reduces anxiety and improves sleep. It grows like a weed, costs almost nothing, and tastes good as tea.
Lemon balm (Melissa officinalis) has been used as a calming herb since at least ancient Greece. Unlike many herbal remedies, it has actually been put through randomised controlled trials — and it holds up.
A 2014 double-blind RCT published in Nutrients found that participants taking 600mg lemon balm extract had significantly reduced stress, anxiety, and insomnia compared to placebo. A 2004 study in Psychosomatic Medicine found reduced stress effects with a single dose. The mechanism is well-studied: lemon balm inhibits GABA transaminase, effectively raising GABA levels — the same pathway as some anti-anxiety medications, but at a gentler, food-safe level.
Why Grow It Yourself
Dried lemon balm in supplement form: $20–40 per month.
Growing it yourself: ~$3 for a seed packet, then effectively free for years. One plant produces enough for daily tea indefinitely — it spreads aggressively if you let it.
Growing Lemon Balm
From Seed (cheapest)
- Fill a small pot with good potting mix.
- Scatter seeds on the surface — don’t bury them, they need light to germinate.
- Mist gently. Cover with cling wrap to keep humidity up.
- Germination: 7–14 days at 18–21°C (65–70°F).
- Once seedlings are 5cm, transplant to a larger pot or garden bed.
From a Cutting (fastest)
If you know someone who grows lemon balm, ask for a cutting. Snip a 10cm stem, remove lower leaves, and place in water. Roots appear within 1–2 weeks. Pot once roots are 2–3cm long.
Growing Conditions
| Factor | Requirement |
|---|---|
| Light | Full sun to partial shade |
| Water | Moderate — keep moist but not waterlogged |
| Soil | Well-draining, average fertility (too rich = less aromatic) |
| Temperature | Hardy to −20°C, thrives 15–25°C |
| Container | Yes — 20cm+ pot works fine on a windowsill |
Note: In the garden, lemon balm spreads via runners. Plant it in a container sunk into the soil, or give it a dedicated bed.
Harvesting
- Harvest once the plant is at least 20cm tall and has 5+ branches.
- Cut stems above a leaf node — the plant regrows from there.
- Harvest in the morning after dew dries, before the heat volatilises aromatic oils.
- You can harvest up to ⅓ of the plant at once.
Using Lemon Balm
Fresh Tea (most bioavailable)
- 2 tablespoons fresh leaves per cup
- Pour water at ~85°C (not boiling — heat destroys some volatile compounds)
- Steep 5–10 minutes, covered
- Drink 1–3 cups/day for anxiety or sleep support
Dried Tea
- Dry leaves in a single layer at room temperature for 1–2 weeks, or 40°C in a dehydrator
- Store in an airtight jar away from light
- 1 teaspoon dried = 1 tablespoon fresh
Tincture (concentrated extract)
- Pack a jar with fresh leaves
- Cover with vodka (40%+ ABV)
- Seal and store in a dark cupboard for 4–6 weeks, shaking occasionally
- Strain and bottle
- Dose: 1–2ml in water, 1–3× daily
How Much Is Effective?
Clinical studies used 300–900mg of standardised extract. A cup of strong lemon balm tea made with 2 tbsp fresh leaves contains roughly 400–600mg of the active compounds when prepared as above.
Cautions
- Generally very safe at food/tea doses
- Possible interaction with thyroid medications (monitor if you’re on these)
- May potentiate sedative medications — space doses out
- Avoid very large doses during pregnancy (insufficient data)
References: Kennedy et al. (2004) Attenuation of Laboratory-Induced Stress in Humans After Acute Administration of Melissa officinalis. Psychosomatic Medicine. Cases et al. (2011) Pilot trial of Melissa officinalis L. leaf extract in the treatment of volunteers suffering from mild-to-moderate anxiety disorders. Mediterranean Journal of Nutrition and Metabolism.