Mentha spicata (Spearmint)
Mentha spicata (Spearmint)
Contents
Introduction & History
Spearmint is the mint — the species most people picture when they hear the word, the one that flavours chewing gum, mojitos, and lamb sauce worldwide. Less pungent than peppermint, with a sweet, warm, unmistakably 'minty' flavour that comes from carvone rather than menthol, spearmint is the most versatile and widely grown mint species on Earth. It is also one of the most aggressively invasive herbs a gardener will ever plant.
History & Origin
Native to Europe and western Asia, now naturalised on every inhabited continent. Spearmint has been cultivated since at least ancient Rome — Pliny described its use in bath water. It was introduced to North America by early European colonists and quickly naturalised. The name 'spicata' refers to the pointed (spicate) flower spikes. It is the parent species (along with water mint) of peppermint.
Botanical Description
Herbaceous perennial spreading vigorously by underground stolons (runners) to form dense patches. Stems are square, 30–60 cm tall, bright green. Leaves are lance-shaped, 5–9 cm long, with serrated edges and a bright green colour — smoother and more pointed than peppermint leaves. Terminal spikes of tiny lilac to white flowers appear in midsummer. The entire plant has the characteristic sweet, warm mint scent.
Stem: Square (quadrangular) — diagnostic for Lamiaceae • Leaves: Opposite, decussate arrangement • Height: 50 cm at maturity • Spread: 90 cm • Foliage: bright green • Flowers: pink-lilac (summer)
Planting & Cultivation
Plant nursery-grown specimens in spring, spacing 30 cm apart — but be warned, it will fill any space available within a season. STRONGLY recommended to grow in sunken containers (bury a bottomless bucket) or standalone pots to contain the stolons. In unrestricted garden soil, mint colonises aggressively. Plant in full sun to partial shade with moist, rich soil.
| Sun exposure | Full Sun Partial Shade |
| Soil pH | 6.0-7.5 |
| Spacing | 90 cm |
| Seed depth | 3–6 mm (surface-sow if light-dependent germinator) |
| Water needs | High |
| Soil type | Well-drained, humus-rich loam; add perlite or grit for drainage |
Cultivation Details
Moist, fertile soil in sun to partial shade. The key cultivation challenge is containment, not growth. Options: grow in containers, plant in buried pots with the rim at soil level, or devote a dedicated mint bed with solid borders. Cut back to ground level in late autumn. In spring, divide and replant to rejuvenate. Top-dress with compost annually. Spearmint tolerates more shade than most herbs.
Climate & Hardiness
Extremely hardy — surviving to −30°C (USDA zones 3–9). Dies back completely in winter, re-emerging vigorously in spring from the underground stolons. Essentially unkillable once established. Tolerates heat but needs consistent moisture. In hot, dry climates, provide afternoon shade and mulch to retain soil moisture.
USDA zones: 3-8
Minimum temperature: -30°C
Indoor growing: Suitable for windowsill culture with 6+ hours light
Seasonal Care
Spring: new shoots emerge; divide and replant if needed; begin harvesting. Summer: peak harvest season; cut back hard mid-summer for a fresh flush of growth. Autumn: final harvest; cut stems to ground level. Winter: fully dormant; the underground stolons survive any cold.
Propagation
Embarrassingly easy. Division of runners in spring — each piece with a node will grow. Stem cuttings in water root in 5–7 days. Stolons pulled from the edge of a patch and replanted. Seed is possible but unreliable (mints hybridise freely). Never grow mint from seed if you want a specific variety — always propagate vegetatively.
| Method | Success rate | Time | Notes |
|---|---|---|---|
| Stem cuttings | 70–90% | 2—4 weeks | Softwood in spring, semi-ripe in summer; 8–12 cm |
| Division | 95%+ | Immediate | Split established clumps in spring or autumn |
| Seed | 50–80% | 14–28 days | Some require cold stratification; germination variable |
| Layering | 80–90% | 6–12 weeks | Pin low branch to soil; sever when rooted |
🌍 Distribution Map
Native origin: Europe, Asia
Diseases & Pests
Mint rust (Puccinia menthae) causes orange-brown pustules on leaves — remove and burn affected material; avoid overhead watering. Aphids on young growth. Spider mites in dry conditions. Whitefly. Flea beetles occasionally. The most serious 'pest' is the plant itself — controlling its spread is the biggest challenge.
Culinary Uses
The world's most-used fresh herb. Essential in: mint sauce for lamb (UK), tabbouleh (Lebanon), mojitos (Cuba), mint tea (Morocco), raita (India), spring rolls (Vietnam), mint julep (USA). Stir into pea soup, scatter over new potatoes, blend into smoothies, muddle into cocktails. Makes outstanding ice cream and chocolate pairings. Use abundantly — mint is one herb that's hard to overdo.
| Category | Pairing suggestions |
|---|---|
| Lamb | Classic pairing; mint sauce/jelly |
| Desserts | Chocolate, fruit salads, ice cream |
| Drinks | Mojito, tea, lemonade, julep |
| Salads | Tabbouleh, Vietnamese rolls, raita |
Medicinal & Aromatherapy
Contains carvone (not menthol — that's peppermint). Traditionally used as a digestive aid, breath freshener, and mild analgesic. Spearmint tea is gentler than peppermint tea — suitable for children and those who find peppermint too intense. The essential oil is used in aromatherapy, oral care products, and chewing gum. Recent research suggests spearmint tea may have anti-androgenic properties.
| Compound | Properties |
|---|---|
| menthol | cooling, analgesic |
| menthone | minty, less cooling |
| pulegone | pennyroyal-like (toxic in excess) |
| linalool | floral, calming |
| rosmarinic acid | antioxidant polyphenol |
Container & Companion Growing
Container Growing
The RECOMMENDED way to grow spearmint. Any container with drainage works — 20+ cm pots are ideal. Use rich potting compost. Water frequently — mint in containers dries out faster than you expect. Feed every 2 weeks with liquid fertiliser during the growing season. Replace the compost annually as mint exhausts it rapidly. Can be grown indoors on a bright windowsill.
• Minimum pot size: 25–30 cm Ø, 10 L+
• Contain runners; solo pot recommended
• Use free-draining potting compost with 20–30% perlite or grit
• Ensure drainage holes; stand on pot feet to prevent waterlogging
• Feed with dilute liquid fertiliser (half-strength) every 2–3 weeks in growing season
• Indoor: Place on brightest windowsill (south-facing ideal); supplement with grow lights in winter
Companion Planting
Plant near brassicas — the strong scent may deter cabbage white butterflies, aphids, and flea beetles. However, NEVER plant mint directly in vegetable beds — it will overrun everything. Grow in containers set among vegetables, or plant in a buried, contained barrier. Attracts hoverflies and other beneficial insects.
| ✓ Good companions | Brassicas, Tomatoes, Peas |
| ✗ Avoid planting with | Chamomile, Parsley |
Common Mistakes to Avoid
Planting directly in garden soil without containment — within one season, mint will invade neighbouring beds. Underwatering, especially in containers. Not cutting back hard enough — regular, aggressive harvesting improves flavour and vigour. Growing mint from seed (unreliable variety). Planting different mint varieties in the same bed (they hybridise and lose distinct flavours).
Harvesting & Preservation
Harvest by cutting stems to 5 cm above ground — the plant responds with vigorous regrowth. Harvest frequently and heavily — it's nearly impossible to over-harvest. For the best flavour, harvest just before flowering. Mint is best used fresh, but freezes well (chop and freeze in ice cube trays with water). Also dries reasonably well for tea — dry quickly in a warm, dark spot to preserve colour.
• Time of day: Early morning, after dew has evaporated but before intense midday heat volatilises essential oils
• Growth stage: Just before flowering, when essential oil concentration peaks. Once flowers open, the plant redirects energy from leaf production
• Season: Spring-Autumn
• Part harvested: Leaves
• Harvest rule: Never remove more than ⅓ of the plant at once; this ensures continued vigorous regrowth
• Technique: Cut stems cleanly above a leaf node with sharp scissors or secateurs. Tearing damages tissue and invites disease
| Method | Process | Shelf life | Best for |
|---|---|---|---|
| Air drying | Tie bundles, hang upside down in warm, dark, airy space | 6–12 months | Most herbs |
| Oven / dehydrator | Spread on trays, 35–45°C until crisp | 6–12 months | Fleshy-leaved herbs |
| Freezing (whole) | Blanch 5s, ice bath, pat dry, freeze flat on tray | 6 months | Basil, chives, parsley |
| Freezing (oil cubes) | Chop fine, pack into ice cube tray, cover with olive oil | 6 months | Any culinary herb |
| Herb salt | Layer herb and coarse salt 1:4, dry and grind | 12+ months | Rosemary, thyme, sage |
| Infused vinegar | Pack jar, cover with warm vinegar, steep 2–4 weeks | 6 months | Tarragon, dill, basil |
| Infused oil | Fill jar with dried herb, cover with oil, steep 4–6 weeks | 3–6 months | Rosemary, thyme, chilli |
Frequently Asked Questions
How do I stop mint from taking over my garden?
Grow in containers — this is the single best solution. If planting in the ground, bury a large pot or bucket (bottom removed) so the rim sits at soil level, containing the runners. Check annually for escaped stolons.
What's the difference between spearmint and peppermint?
Spearmint contains carvone (sweet, warm mint flavour) while peppermint contains menthol (cooling, intense mint). Spearmint is milder and more versatile in cooking. Peppermint is stronger, better for tea, medicine, and candy.
Can I grow mint indoors?
Yes — mint grows reasonably well on a bright windowsill. Use a 20+ cm pot with rich compost. Water frequently. It won't be as vigorous as outdoor mint but will provide usable sprigs year-round. Supplement with grow lights in winter for better results.
Seasonal Care Calendar
🌱 Spring (Mar–May)
Water: Regular
Feeding: Regular feeding
☀️ Summer (Jun–Aug)
Water: Very Heavy
Feeding: Heavy feeding
🍂 Autumn (Sep–Nov)
Water: Regular
Feeding: Light feeding
❄️ Winter (Dec–Feb)
Water: Light
Feeding: No feeding
The world's most popular mint — sweet, warm carvone flavour for mojitos, mint sauce, and tabbouleh. Extremely hardy (zones 3–9) and aggressively invasive — ALWAYS grow in containers. Cut back hard and harvest frequently. Moist soil, sun to partial shade. Impossible to kill, hard to contain.
Quick Reference: Mentha spicata
Key Principles: Right location, well-drained soil, regular harvesting to promote growth, and appropriate winter protection for tender species.