How to grow mint
Overview
Mint (Mentha spicata) is a vigorous perennial herb grown for its aromatic leaves, used in teas, cooking, and as a garden companion. It spreads rapidly via underground runners and is best contained in pots to prevent it overtaking garden beds.
Varieties
- Spearmint — The classic culinary mint with bright green, pointed leaves and a mild, sweet flavour.
- Peppermint — A stronger, more pungent variety with dark leaves and purple stems, ideal for tea.
- Apple Mint — A fuzzy-leaved, fruity-scented mint that is less invasive and good for desserts.
- Chocolate Mint — A dark-stemmed variety with a hint of chocolate aroma, popular in cocktails and teas.
- Mojito Mint — A Cuban mint with a clean, bright flavour, perfect for drinks and salads.
Soil Preparation
Mint prefers a loamy, well-drained soil rich in organic matter, with a pH of 6.0–7.0. Before planting, mix in compost or aged manure to improve moisture retention. Ensure good drainage to avoid root rot; add sand or perlite if soil is heavy clay.
Growing Guide
Plant mint in a pot or a sunken container to restrict root spread. Use a rich, moisture-retentive soil and position in part shade, avoiding harsh afternoon sun. Space plants 30–40 cm apart if in ground; for pots, use a 20–30 cm diameter container. Keep soil consistently moist, especially during active growth in spring and summer. Mulch heavily to retain moisture and suppress weeds.
Sowing
Mint is rarely grown from seed; it is best propagated from cuttings, divisions, or runners. If sowing, scatter seeds on the surface of moist soil and cover lightly with vermiculite. Germination takes 10–15 days at 20–25°C, but seedlings are slow to establish compared to divisions.
Care
Feed mint with a balanced liquid fertiliser (e.g., seaweed or fish emulsion) every 4–6 weeks during spring and summer. Prune back to 5 cm above soil level in autumn to rejuvenate growth. Divide potted plants every 2–3 years to prevent root congestion and maintain vigour.
Companion Planting
Mint deters cabbage moths, aphids, and ants, making it a good companion for brassicas (cabbage, broccoli, kale) and tomatoes. Avoid planting near parsley or chamomile, as mint can inhibit their growth. Keep mint isolated in a pot to prevent it from smothering neighbours.
Common Pests & Risks
Mint rust (Puccinia menthae) causes orange spots on leaves; remove infected foliage and avoid overhead watering. Aphids and spider mites can attack in dry conditions; spray with neem oil or a strong jet of water. Good air circulation and regular pruning reduce pest pressure.
Harvesting
Harvest mint by cutting leafy stems just above a leaf node, starting when plants are 15–20 cm tall. Pick regularly to encourage bushy growth and prevent flowering, which reduces leaf flavour. For best flavour, harvest in the morning after dew has dried.
In the Kitchen
Use fresh mint leaves in teas, salads, sauces (e.g., mint sauce for lamb), and cocktails (mint julep, mojito). To store, wrap stems in a damp paper towel and refrigerate for up to a week, or freeze leaves in ice cubes. Dried mint loses much of its flavour, so use fresh for best results.
Troubleshooting
Yellow leaves: overwatering or poor drainage — reduce water and improve soil. Brown leaf edges: sun scorch or dry soil — move to more shade and water consistently. Rusty spots: mint rust — remove infected leaves and avoid overhead watering. Stunted growth: pot-bound roots — divide and repot every 2–3 years. Leggy stems: insufficient light — move to brighter part shade.