How to Grow Mint in a Greenhouse? When to Plant and How to Care

Have you ever tried to grow mint in your garden, only to end up with weak, limp shoots without a distinctive aroma? Or planted seedlings, but after a couple of weeks they turned black, fell off, or became covered with a white coating?
Perhaps you are simply tired of depending on the weather, pests and bad soil. Or do you want to grow mint not only for yourself, but go further - sell it to tea factories, beauty salons or restaurants?

In any case, you've come to the right place.

Mint is a crop that, with the right approach in a greenhouse, can produce a stable aromatic harvest up to four times per season, and with heating - all year round. But success depends on many factors: what kind of greenhouse is chosen, when and how to plant, what regime to create, and how to avoid typical mistakes - from over-moistening to loss of essential oil content.

In this article, prepared by experts from the Nova Teplitsa company, we will examine in detail:

• what type of greenhouse design to choose for mint;
• when and how to plant to get lush, strong greenery;
• how to properly care for it and what to be wary of;
• and most importantly, how to squeeze the maximum benefit and aroma out of each leaf.

If you want to grow mint not by chance, but according to science, read to the end.

Why is it worth growing mint in a greenhouse?

Open ground is dependent on the vagaries of the weather. In a greenhouse, you control everything: temperature, humidity, lighting, protection from pests. And mint is sensitive to these parameters. In closed ground:

• the essential oil content of the leaf increases (more aroma and value);
• vegetation periods are reduced by 20–30%;
• it is possible to collect up to 3-4 harvests per season, and with heating - all year round;
• Less illness and loss with proper ventilation.

Which greenhouse to choose for mint: comparison of options

Basic requirements for mint in a greenhouse:

• temperature: +20…+28 °C during the day, not lower than +12 °C at night;
• humidity: 60–70%, not higher – otherwise there is a risk of fungus;
• good ventilation, no drafts;
• stable illumination (additional light in winter - as needed);
• capacity for shelves or containers (mint grows well in boxes).

Type of greenhouse	Advantages	Is it suitable for mint?	Peculiarities
Arched polycarbonate	Reliable thermal insulation, uniform light, durability	✔ Yes, the best option for seasonal and year-round cultivation	Optimal for coating thicknesses of 6 mm and above, easy to add ventilation
Straight wall polycarbonate	Suitable for shelves, containers and hydroponic systems	✔ Excellent, especially for commercial purposes	Requires good ventilation and sealing
Film (arched)	Low cost, quick warm-up in spring	✔ Only for spring-summer season	Suitable for growing from May to September, at temperatures not lower than +10 °C at night
Heated greenhouse	Year-round cultivation, automation possible	✔ Ideal for business, contracts, supplies	Requires investment in heating, humidity control and lighting

Recommendation from Nova Teplitsa: If you plan to grow mint seriously, choose an arched or straight-walled greenhouse with a 6-10 mm cellular polycarbonate covering. This will provide warmth, light and protection from temperature changes. For regions with severe winters, it is advisable to install automatic ventilation and heating.

When to plant mint in a greenhouse?

Mint can be planted both as seedlings and by dividing the rhizomes (for perennial varieties). The timing depends on the type of greenhouse:

Type of greenhouse	Sowing/planting	Note
Heated	January – March (seedlings), August – September (repeat cycle)	Year-round turnover is possible
Unheated polycarbonate	April (at a temperature in the greenhouse of not less than +12 °C)	Seedlings can be grown in advance at home
Film	May - June	Only in stable weather and night temperatures above +10 °C

Important: Mint is extremely sensitive to excess moisture and acidic soil. Before planting:

• neutralize the soil (pH 6.5–7.0);
• prepare a loose mixture of humus, peat, sand and turf soil;
• Provide drainage in beds or containers.

How to care for mint in a greenhouse: step-by-step recommendations

1. Lighting

• Mint loves light, but not direct, scorching sun.
• In greenhouses with southern exposure, light shading is recommended from 11:00 to 16:00 in summer.
• In winter, install LED phytolamps (additional lighting up to 12–14 hours per day).

2. Temperature

• Optimum: during the day +22…+26 °C, at night +15…+18 °C.
• When overheated, the menthol content decreases, the plant “gets fat” (lots of greenery, little aroma).

3. Watering

• Regular but moderate. Drip irrigation is best.
• Frequency: 2–3 times a week, 1–1.5 l per bush.
• Avoid overwatering, as this will encourage rot and powdery mildew.

4. Humidity and ventilation

• Air humidity: 60–70%.
• The presence of transoms, vents or ventilation with automation is mandatory.
• Drafts and temperature changes are the main enemies of mint in a greenhouse.

5. Feeding

• 2 weeks after planting: nitrogen fertilization (urea, nettle infusion).
• Then every 2 weeks - complex fertilizers with potassium and magnesium.
• 7 days before harvesting, fertilizing stops.

6. Collection and pruning

• The first cut is made 35–45 days after planting.
• Cut to a height of 5–7 cm from the ground.
• Repeated cutting - every 20-25 days (up to 4 harvests per season).
• After each cut, apply phosphorus-potassium fertilizers.

Diseases and pests: what to look out for

Although a greenhouse is a protection from external factors, if the regime is violated, the following often occur:

Problem	Cause	Solution
Powdery mildew	Overwatering, thickening	Thinning, ventilation, fungicides (Topaz, Bayleton)
Root rot	Stagnant water, poor drainage	Improve the soil, use Fitosporin
Aphids, spider mites	High temperature, dry air	Biological preparations (Fitoverm), sticky traps, regular checks

Growing mint in a greenhouse

Mint is not only aroma and taste, but also profit. Growing it in a greenhouse, you get:

• crop protected from weather and diseases;
• the ability to harvest mint all year round;
• control over the quality and environmental friendliness of products.

Nova Teplitsya company offers ready-made solutions for growing mint - from compact greenhouses for summer cottages to professional complexes for business. We will tell you which frame to choose, which coating will withstand humidity and steam, how to organize watering and lighting. With us, your greenhouse will work for the result - fragrant, strong and profitable.