Mint
Mentha spp.
Mint is a vigorous perennial herb that spreads aggressively by underground runners and is best contained in a buried pot or raised bed section. It dies back to the ground in winter and re-emerges reliably each spring. Regular cutting encourages fresh, leafy growth and prevents the plant becoming straggly or flowering too early.
Key facts
- Family
- Lamiaceae (Mints)
- Category
- Herb
- Sowing window
- Mar–May
- Sowing depth
- 5 mm
- Watering
- medium
- Frost sensitivity
- low
- Days to maturity
- Approx 8 weeks from rooted cuttings to first harvest
- Harvest window
- Apr - Oct
Sowing notes
- -Propagate from runners or cuttings - seed is unreliable and often off-type
- -Extremely invasive - plant in a sunken container to contain roots
- -Perennial - dies back in winter and re-emerges in spring
- -Cut back hard to stimulate fresh leafy growth
Varieties
Peppermint has a more intense, menthol-rich flavour than spearmint, making it the preferred mint for herbal teas and confectionery. It is a natural hybrid (spearmint × watermint) and is best propagated from cuttings as seed does not come true. Like all mints, it needs to be contained to prevent it spreading throughout the garden.
Spearmint is the most common garden mint in the UK, with a fresh, clean flavour used in sauces, drinks, salads, and as a digestif tea. It is highly vigorous and spreads rapidly via underground runners if not contained. The flavour is milder and sweeter than peppermint and preferred for most culinary uses.
Issues & threats
Wilting
EnvironmentalPlants are drooping or losing vigour. Most commonly caused by water stress but can also indicate root damage, vascular disease, or heat scorch. Identifying the cause quickly is important as some causes are serious.
Poor germination
EnvironmentalSeeds are emerging unevenly or not at all. Usually caused by soil temperature being too low, seeds sown too deep, poor seed-to-soil contact, or old seed stock.
Damping off
Fungal diseasePythium spp. / Phytophthora spp.
Young seedlings collapse at or just below soil level, caused by fungal pathogens that thrive in overwatered, poorly ventilated growing conditions. Can spread rapidly through a seed tray.
Yellowing leaves
EnvironmentalLeaves are turning yellow, which can indicate a range of problems including nutrient deficiency, overwatering, disease, or natural senescence. Identifying whether the pattern is upper or lower leaves, whole leaves or between veins, is key to diagnosis.
Stunted growth
EnvironmentalPlants are significantly smaller or slower to develop than expected. May be caused by poor soil, nutrient deficiency, root restriction, compaction, pest damage to roots, or disease.
Chewing damage
PestGeneral chewing damage from an unidentified pest, leaving holes or missing leaf sections. May be caused by caterpillars, beetles, or other insects. Inspect at dusk to identify the culprit.
Sap-sucking pests
PestGeneral sap-feeding pest activity causing weakened or distorted growth. May be caused by aphids, whitefly, scale insects, or other sucking insects. Inspect leaf undersides and growing tips to identify the pest.