Herb
Spearmint
Mentha spicata · Lamiaceae (mint family)
Also called: Common Mint, Garden Mint
Spearmint (Mentha spicata) is a moderate-water herb well suited to Tucson and the low desert. It thrives in part shade in Tucson. Expect pale lilac to white blooms summer.
Spearmint at a glance
- Water use
- Moderate (established)
- Sun
- Part shade in Tucson; morning sun with afternoon shade is ideal. Full afternoon sun scorches the foliage in summer.
- Mature size
- 12-24 in. tall; spreads indefinitely by runners (contain in pots)
- Growth rate
- Fast (aggressive spreader)
- Bloom
- Pale lilac to white, Summer (pinch flowers to keep leaves tender)
- Cold hardiness
- Cold-hardy perennial in Tucson (USDA 9a-9b); frost-tolerant and dies back lightly in cold snaps, returning in spring. Summer heat and dry soil are the real threats.
- Soil
- Moisture-retentive, fertile, well-drained soil amended with compost; tolerates a range of pH. Avoid planting in open ground unless you want it to take over.
- Native range
- Europe and Asia (Mediterranean region); naturalized widely
- Best used as
- Culinary herb (teas, mojitos, tabbouleh, sauces, desserts), Container plant (strongly recommended to control spread), Pollinator plant
- Wildlife
- Flowers attract bees and butterflies; strong scent deters many browsing pests.
- Toxicity
- Non-toxic to people. Generally considered safe but can cause mild stomach upset in dogs and cats if eaten in quantity; concentrated mint oil is more problematic for pets.
How to grow Spearmint in Tucson & the low desert
Watering
The thirstiest of these herbs; keep soil consistently moist and never let it dry out fully, especially in summer heat. Best grown in a pot, which also contains its aggressive spreading roots.
Fertilizer & nutrients
Light to moderate feeder. Feed with a balanced or all-purpose fertilizer every 4-6 weeks during active growth, or top-dress with compost; it tolerates richer soil than the Mediterranean herbs.
Pruning & care
Harvest and shear frequently to keep it bushy and prevent flowering. Cut back hard if it gets leggy; it rebounds vigorously. Divide or repot containers yearly to refresh.
Notes
Grow spearmint in a container in Tucson, both to provide the steady moisture and afternoon shade it needs and to contain its invasive runners. Higher water use than the other herbs here. Plant in fall or spring; it will run year-round with protection from harsh afternoon sun.
Sources: University of Arizona Cooperative Extension / Pima County Master Gardeners; Missouri Botanical Garden Plant Finder; ASPCA toxic-plant database; AMWUA plant guidance