How to Grow Hydroponic Mint: No Soil, No Problem

There are over 500 types of mint, botanists define slightly less than 30 species with the remaining 400+ being hybrids of these primary species.

Common characteristics of all mint plants are the volatile and essential oils that create their hallmark menthol aroma and flavor. Another common characteristic of most mint plants is that they thrive under similar conditions, one of these conditions is moisture which makes them good candidates for hydroponic gardens.

Plants that produce green leafy growth such as lettuce, kale, and spinach fare well in hydroponic scenarios.

Mint, which is grown for its aromatic and flavorful foliage is an herb that does well hydroponically also, so long as particular caveats are adhered to.

How to Grow Hydroponic Mint

Most mint plants are that they thrive under similar conditions, although there are minor exceptions to every rule. Light requirements, pH, nutrients are some of the nearly universal requirements for successfully growing mint.

  • pH 6.0 – 6.8
  • EC 2.0-2.4
  • PPM 1400-1680

Humidity: 70 – 75%

During the rooting phase, if growing from cuttings humidity should be around 85 – 90% until roots are established which is generally 7 to 10 days.

Temperatures: Night Cycle: 50 – 55 F. Day Cycle: 65 – 70 F. Temperatures above 85 F stalls mint growth.

Light: 12-16 hours of light daily optimal.

Mint can be started from seed but is more commonly began with cuttings/clones or rootstock. Presoak all media {LCA, Rockwool, vermiculite…} in a pH balanced water for about 45 minutes before using it. Dry media will soak up moisture from the plant’s roots.

Nutrients for Hydroponic Mint

3 different pictures of mint. Two pictures of mint leaves and another of a mint plant with stem and leaves.

Mint doesn’t ask a lot so far as nutrients are concerned, a simple balanced formula is all that is needed. Do not use a high nitrogen formula as it may lead to lush green mint leaves that are grossly substandard in flavor.

Various nutrient solutions have different concentrations and water to nutrient ratios. It is best to follow the directions that came with your nutrient solution. I like to keep in mind that the manufacturers of these nutrients are in business to sell their product and will usually advise slightly more than is absolutely needed.

In no case should you exceed their suggestions as they are already towards the high end of the curve.

Hydroponic Mint Lighting Requirements

In nature full sun for nearly all mint varieties forces the plant to concentrate its oils and develop a more intense mentholated flavor and aroma.

Light shade is fine and will produce a less intense flavor which is desirable in some instances. During the rooting phase, partial shade / less intense lighting is advantageous.

Light sources should be far enough from the plants so that it will not singe or dry them, keep in mind that light = heat. The light source should also be close enough to be effective, you can test this by placing the back of your hand at the top of your plants.

If the heat is uncomfortable to your skin, it’s also not healthy for the plants. Standard fluorescent lamps can generally be 2 to 5 inches from the plant tops, compact fluorescent and high output about one foot, and HID lights between 2 and 4 feet from the plant tops.

These distances are not written in stone and multiple variables such as wattage and so forth affect these guidelines, so if you are slightly skeptical in your particular situation use the hand test described earlier in this paragraph.

See: Grow Lights

Ventilation and Airflow

Also keeping in mind that light = heat brings the topic of ventilation into play. Good air flow is essential for plant vigor and is a critical hydroponic factor that most certainly should not be overlooked.

Keeping your grow room temperatures within the correct parameters can be bothersome at times, especially when using heat-producing grow lights.

Using ventilation will not only prevent excessive heat and moisture buildup but will also help to provide the plants with ample carbon dioxide.

See: Hydroponic Ventilation

Harvesting Hydroponic Mint

Mint matures rapidly once it gets growing. Some growers, particularly commercial operations, prefer to harvest completely after each 3 – 4 week cycle.

Hobbyists and home growers may prefer to harvest gradually, as needed, allowing the plant to rejuvenate and produce new foliage for future harvest.