Mint

Quick growing conditions

How to Grow Mint Hydroponically at Home

Hydroponic mint provides fresh, aromatic leaves for tea, salads and cooking. It grows well without soil and can produce repeated harvests under suitable indoor conditions.

The main priorities are adequate light, healthy roots and regular cutting to encourage fresh shoots.

Which Mint Should You Choose?

Choose a correctly labelled culinary mint:

• Spearmint, Mentha spicata: a familiar flavour for cooking, sauces and drinks.
• Peppermint, Mentha × piperita: a stronger, cooling flavour, popular for tea.
• Moroccan mint: a popular choice for fresh mint tea.

Healthy rooted cuttings preserve the flavour and characteristics of the original plant. This is especially useful for named varieties and hybrids.

Mint is a perennial, so it can regrow after harvesting. Its vigorous roots and spreading shoots need room and regular attention.

Main Growing Conditions

These are starting guidelines, not strict biological limits. Growth varies with species, light and temperature. Cooler conditions generally slow regrowth.

Mint can also grow in warmer conditions. The Japanese mint nutrient study operated at air temperatures of 28–30°C, but this does not establish an optimum for every mint.

The nutrient solution does not need to be warmer than the room. Avoid unnecessary heating and prolonged reservoir overheating.

Kilolux readings are approximate because lamp spectra differ. Adjust lighting if stems stretch excessively or leaves show signs of scorching.

Suitable Hydroponic Systems

Mint can grow in NFT channels, aerated deep water culture or a substrate system supplied with nutrient solution.

Keep the base of the leafy stems above standing water and ensure the roots receive oxygen.

Mint develops a substantial root mass. In NFT systems, inspect channels and outlets regularly to prevent roots from restricting flow.

Give mint its own growing space where possible. Remove unwanted runners before they crowd neighbouring plants.

Nutrient Solution Profile

The following complete profile was used by Janpen and colleagues (2019) for Japanese mint, Mentha arvensis, grown in deep water culture.

All values are mg of element per litre of finished nutrient solution.

Source: “Physiological responses of hydroponically-grown Japanese mint under nutrient deficiency”.

This is the complete control solution, excluding the experimental nutrient-deficiency treatments. The study maintained pH at 6.5–7.0.

For spearmint and peppermint, use this formula as a starting point rather than a proven species-specific optimum. Modify it during growth according to plant response and your growing conditions.

N, P and K are elemental concentrations, not fertiliser quantities or P₂O₅ and K₂O. Account for nutrients already present in your water and measure EC after mixing.

Calculate your fertiliser quantities with our NPK Calculator.

Keeping Mint Bushy and Productive

Harvest shoot tips regularly, cutting just above a pair of leaves. Leave healthy leaves below the cut to support new growth.

Remove old, damaged stems and unwanted spreading shoots. Keep the reservoir covered and provide gentle airflow through the foliage.

For leaf production, remove flower buds as they appear. Flowering does not end the plant’s life, and established mint can produce fresh shoots after cutting back.

Pollination is unnecessary when growing mint for leaves.

When and How to Harvest

Harvest when plants have several healthy shoots and enough foliage to recover after cutting. Established plants may provide small pickings before they are ready for a full canopy harvest.

In a 2024 hydroponic study, established spearmint plants reached their first full harvest after 37–42 days in the production system, and peppermint after 49 days. Subsequent harvests followed after approximately 30–46 days.

These times exclude the earlier rooting and nursery period. They are examples from a specific experiment, not a fixed schedule for every home system.

Read the regrowth study.

For everyday use, take young shoot tips and leave sufficient foliage for recovery. After a heavier cut, wait for strong new growth before harvesting again.

Use clean scissors. Mint can remain productive for months, but replace or divide crowded, declining plants when necessary.

Common Problems, Pests and Diseases

• Long stems with widely spaced leaves: check light levels and overcrowding.
• Pale leaves or weak regrowth: check pH, nutrient supply and root health.
• Wilting despite available water: inspect roots, oxygen supply and solution temperature.
• Orange or brown powdery spots: suspect mint rust.
• Curled shoots with clusters of insects: inspect for aphids.
• Pale mottling or chewed leaves: inspect for leafhoppers, beetles or caterpillars.

Hydroponics does not eliminate pests or diseases. Inspect new plants before introducing them to your system.

For pesticide-free home growing, prioritise healthy planting material, clean equipment, insect exclusion and physical removal. Suitable biological controls can help where available.

Remove badly affected plants and avoid keeping the foliage persistently wet.

Need Help?

Join the Grow Like Pro Telegram channel for growing updates and support. We will be happy to help with your questions.

Further Growing Reference

RHS, growing mint

Sources

• Janpen et al. (2019), Physiological responses of hydroponically-grown Japanese mint under nutrient deficiency
• Ciriello et al. (2024), Hydroponic mint regrowth study
• RHS: How to grow mint