Lemon balm
Melissa officinalis
also called melissa
Lemony mint-relative humming with bees — contain its roots.
- Type
- Herb · Perennial
- Botanical family
- Mixed / other
- Foliage color
- Green
- Sunlight
- Full sun to part shade
- Watering
- Moderate
- Soil
- Moist, well-drained
- Feeding
- Feeding is rarely needed — a light compost mulch in spring is plenty.
- USDA zones
- 4a–9b
- Frost tolerant
- Yes
- Flowering
- June
- Pruning
- Cut it hard back before it flowers, then shear the whole plant to the ground in autumn.
- Sow indoors
- 28 days before the last spring frost
- Plant out
- at the last spring frost
- First harvest
- 45 days after the last spring frost
- Harvest ends
- 14 days after the first fall frost
- Mar–Apr Spring Growth
- Apr–Jun Harvest
- Jun–Oct Flowering
- Oct–Dec Growing
- Jan–Mar Growing
- Plant spacing
- 15.7 in
- In-row spacing
- 13.8 in
- Between rows
- 17.7 in
- Square-foot density
- 1 per square
- Root system
- Fibrous
- Working depth
- 12–24 in
- Can reach
- 3 ft down where the soil allows
- Spread
- 18 in–2 ft across, about 1–1.5× the width of the plant
- Shallowest pot
- 12 in of soil
A dense mass of roots through the topsoil with a few running deeper after water. Work the bed to a spade’s depth before planting and it will find everything it needs without much help.
The habit is Lemon balm’s own; the figures are what that habit usually comes to at this size, not a measurement of this species. Roots follow the soil either way: a compacted pan, a high water table or heavy clay stops them well short of any of it, and deep open ground lets them go further.
- Cats and dogs
- Confirmed safe
We say a plant is safe only where a named poison-control reference names that exact species and records it as non-toxic to both cats and dogs. Most plants are on nobody’s list, and their absence here is not a judgement about them. This is a record of what those references say, not veterinary advice, and it cannot account for your own animal, the quantity eaten, or a plant treated with anything.
- When
- Cut from late spring until autumn, with the prime harvest just before flowering in early–mid summer when the lemon-scented oils peak. Pick in the morning after dew has dried; the leaves' aroma fades fast in afternoon heat.
- What to look for
- Lush, bright-green, crinkled leaves with a powerful lemon scent when rubbed. Buds forming at stem tips signal the moment for a hard preserving cut; once in full flower the leaves turn noticeably coarser and less fragrant.
- How to harvest
- Pinch stem tips for daily use, or for the main harvest shear entire stems back to 5–8cm above the crown with shears — lemon balm regrows from the base with vigor. Handle gently and process quickly, as the leaves bruise and blacken easily.
- How often
- An established clump tolerates two or three hard cuts per season, each followed by a fresh flush in 3–4 weeks. Cutting before flowering also prevents its notorious self-seeding all over the garden.
- Storing the crop
- Fresh leaves keep only 2–3 days in the fridge and lose scent quickly. Dry fast in a dehydrator or a warm dark airy spot (slow drying browns it and loses the lemon note), or better, freeze chopped leaves in ice cubes for teas; it also makes a lovely infused honey or syrup.
- Generally trouble-free No notable pest or disease problems when grown in the right conditions — one of the easy ones.
Tomatoes, Squash, Fruit trees
Crush a leaf for a burst of lemon — it's a mint relative whose name, Melissa, means 'bee'.
Green-leaved herbs, like this one.
The Cottage Garden Companion — the gardener's herbarium at cottagegardencompanion.com