How to Grow Mint Indoors

Can you grow mint indoors?

Yes. Mint grows well indoors year-round in any US climate zone, provided it gets at least 4–6 hours of direct sun daily from a south- or west-facing window. Without adequate light, the plant survives but produces weak, pale growth with reduced flavor.

The good news for apartment and small-space gardeners: mint is one of the most forgiving herbs for indoor growing. It tolerates being pot-bound longer than most herbs, recovers quickly from missed waterings, and regrows rapidly after harvest.

The bad news: mint does spread aggressively indoors if given a large container. Plant it in its own dedicated pot rather than in a mixed herb planter. Once mint roots establish, they crowd out companions within a single growing season.

This guide covers what US gardeners actually need to know — from window selection and container choice through harvesting, overwintering, and troubleshooting the problems that kill most indoor mint plants.

Choosing the right window: light is the main variable

The single most important factor for indoor mint success is light. A south-facing window is the ideal placement in the US. East or west windows work with grow light supplementation. North-facing windows alone are insufficient.

Light needs by window direction in the US:

In northern US states (Zones 3–6), all windows lose significant light intensity from November through February. Even a south-facing window in Minnesota or Vermont may not deliver sufficient light intensity in January. A full-spectrum LED grow light placed 4–6 inches above the plant and run for 12–14 hours daily bridges the gap.

Extension researchers at the University of Vermont found that culinary herbs including mint require a minimum of 4 hours of direct sun or an equivalent DLI (daily light integral) of about 12–15 mol/m²/day for productive growth. Below that threshold, plants survive but become leggy and flavorless.

What container should I use for indoor mint?

Use a pot at least 6 inches wide and 6 inches deep with drainage holes. Terracotta is preferred over plastic because it breathes and dries more evenly, reducing the risk of root rot.

Container selection matters for two reasons:

1. Drainage holes are non-negotiable. Mint in a pot without drainage will develop root rot within weeks, especially in a warm indoor environment. Decorative cachepots without drainage work only if you use a nursery pot inside and never let water accumulate.

2. Size affects watering frequency. A smaller pot (4–5 inches) dries out faster and needs watering every 1–2 days in a sunny window. A 6–8-inch pot retains moisture longer and is more forgiving. Oversized pots (10+ inches) stay wet too long for a single mint plant and increase rot risk.

Terracotta pros:

• Allows air exchange through pot walls, reducing root rot risk
• Dries more evenly than glazed ceramic or plastic
• Provides some weight stability on a windowsill

Terracotta con: dries out faster in heated indoor air during winter — you may water more frequently than with a plastic pot.

Best soil for indoor mint

Use a lightweight potting mix formulated for containers, not garden soil. Add 20–25% perlite to improve drainage. Mint prefers slightly acidic soil — pH 6.0–7.0.

Garden soil from the yard compacts in containers, restricts root growth, and does not drain properly. A standard container potting mix (like Miracle-Gro Performance Organics or similar) provides the right drainage and aeration for indoor mint.

Soil recipe that works well:

• 3 parts standard potting mix
• 1 part perlite
• Optional: 1 tablespoon of worm castings mixed into the top layer at planting

Refresh or replace the potting mix every 12–18 months. Mint roots slowly deplete nutrients and compress the soil over time, reducing drainage.

Planting or transplanting indoor mint

Start with a transplant from a garden center nursery division of a larger plant you already own. Mint seeds are slow and unreliable — transplants establish in 2–3 weeks and are productive within a month.

Planting steps:

1. Fill a 6-inch pot with moistened potting mix to 1 inch below the rim
2. Make a hole in the center large enough for the root ball
3. Remove mint from its nursery pot and gently loosen roots if they are circling
4. Place the plant so the crown sits at soil level — not buried, not elevated
5. Firm soil around the base and water thoroughly until water runs from the drainage hole
6. Place in the brightest available window

If transplanting from outdoor-grown mint at the end of the summer season, cut plants back by half before bringing them inside. This reduces transplant stress and encourages compact new growth suited for indoor conditions.

How often should you water indoor mint?

Water when the top half-inch of soil feels dry. This is typically every 2–3 days in a warm, sunny window and every 4–5 days in winter or lower-light situations.

The biggest mistake with indoor mint is watering on a fixed schedule rather than checking the soil. Indoor environments vary dramatically in temperature and humidity — the same pot may need water daily in a warm, dry apartment and every 4 days in a cool, humid one.

Signs of underwatering:

• Leaves are wilting or curling inward
• Soil is pulling away from the sides of the pot
• Plant feels very light when lifted

Signs of overwatering:

• Lower leaves yellowing and dropping
• Stems turning brown or mushy at the base
• Persistent gnats around the soil surface (a sign of consistently wet soil)

For indoor gnat problems associated with overwatered herb pots, our homemade gnat trap guide covers non-toxic control methods.

Winter watering tip: Indoor heating systems dry the air significantly, which can make soil seem to dry out faster than the plant actually needs. In winter, reduce watering frequency by 20–30% compared to summer to match the plant’s slower growth rate.

Fertilizing indoor mint

Fertilize monthly with a half-strength balanced liquid fertilizer (like 10-10-10). Over-fertilizing reduces flavor concentration — the essential oils that give mint its characteristic scent are less concentrated in fast, heavily-fed growth.

Fertilizer schedule:

• March–October (active growth): Liquid fertilizer at half the recommended rate, once per month
• November–February (reduced growth): Fertilize every 6–8 weeks, or skip fertilizing entirely if the plant is not actively growing

A fertilizer with moderate nitrogen supports leaf production without pushing excessively watery, flavorless growth. Avoid fertilizers with very high nitrogen ratios (like 30-10-10) for culinary herbs — the tradeoff in flavor is noticeable.

Harvesting indoor mint

Cut stems back to 1–2 inches above the soil, removing no more than one-third of the plant at one time. The plant regrows from the base within 2–3 weeks.

Regular harvesting encourages bushy, compact growth. Plants that are never harvested become leggy and woody over time. Cutting back stimulates new growth from the base and keeps the plant producing fresh, flavorful leaves.

Harvest guide:

• Take the longest, most mature stems first — these have the most flavor
• Cut just above a leaf node (where two leaves emerge from the stem) to encourage branching
• Harvest in the morning when essential oil concentration is highest
• A single 6-inch pot produces 2–4 tablespoons of fresh leaves per harvest cycle

After 3–4 harvests in a single season, give the plant a 4–6-week rest period with lighter watering and no fertilizer before resuming heavy harvesting.

Comparing common indoor mint varieties

Spearmint is the best starting variety for US gardeners growing mint indoors for the first time. It is the most forgiving of low-light conditions and produces the most usable leaves per pot.

For outdoor mint growing and containment strategies, see our mint plant care guide.

Repotting indoor mint

Repot every 6–12 months or when roots push through the drainage holes. Mint fills its container rapidly and becomes rootbound, which reduces growth and increases watering difficulty.

Signs it is time to repot:

• Roots visible from the drainage holes
• Plant dries out within 24 hours of watering even with moderate-sized pot
• Growth has significantly slowed despite adequate light and fertilizer
• Soil has become dense and no longer drains freely

Repotting steps:

1. Water the plant thoroughly 24 hours before repotting
2. Choose a pot 1–2 inches larger in diameter than the current one
3. Gently remove the plant and loosen any circling roots
4. Place in fresh potting mix at the same depth as before
5. Water well and return to the same window position

Alternatively, divide the root ball with a clean knife and repot each half separately — an easy way to get two productive mint plants from one.

Troubleshooting common indoor mint problems

Growing mint indoors alongside other herbs

Mint competes aggressively with other plants. Give it its own pot — always. Even in a large planter, mint roots spread laterally and outcompete slower herbs like basil and cilantro within weeks.

Herbs that grow well in separate pots on the same windowsill as mint:

• Chives: Similar water and light requirements, compact habit
• Rosemary: Prefers less water than mint but tolerates the same sunny window
• Parsley: Works well alongside mint in similar light conditions

For a full comparison of indoor herb growing, our rosemary plant care guide covers the light and water differences between rosemary and mint that matter for windowsill herb growing.

For broader guidance on keeping indoor plants thriving through seasonal light changes, see our how to keep plants alive guide.