Best Pot for Mint: Size, Depth and Material for Containers

The Best Pot for Mint, in Short

The best pot for mint is about 12 to 16 inches in diameter and holds 2 to 5 gallons of potting mix, with drainage holes in the base. Material matters less than placement. Choose plastic or resin if you want to water less often, and stand whatever you buy on a patio, deck or paver, where a runner that leaves the pot is easy to see and cut. One mint plant fills a pot that size, so buy one container per variety.

Mint is grown in pots for a different reason than most herbs. University of Illinois Extension describes mints as plants that grow 1 to 3 feet tall and spread aggressively by underground rhizomes, and it suggests growing them in containers above ground for exactly that reason. The pot is a fence as much as a home.

What Size Pot Does Mint Need?

Two extension measurements define the target. University of Maryland Extension says to grow mint in a container about 12 to 16 inches in diameter to keep it from taking over. Its container guide puts mint in the group of small herbs, with basil, cilantro, thyme and oregano, that do well in 2- to 5-gallon pots. Larger herbs such as rosemary and bay need 5 gallons or more.

Width and depth do different jobs. Mint spreads by rhizomes, so a wide pot gives the plant room to run before it fills the container, and a deeper pot holds more potting mix. Neither guide gives a depth for a standing pot, but volume sets it. One US gallon is 231 cubic inches, so a straight-sided pot 12 inches across has to be about 10 inches deep to hold 5 gallons. A 5-gallon bucket sits at the top of the small-herb range. Drill drainage holes in a bucket before planting.

Container	Size	Good for	Watch for
Standard round pot	12 to 16 inches across	One plant on a patio or balcony	Runners creeping over the rim
Small-herb pot	2 to 5 gallons	One plant, easy to move	Less mix to hold water at the 2-gallon end
Bucket with holes drilled	5 gallons	One plant, top of the small-herb range	Plain looks
Bottomless pot sunk in a bed	Rim about 1 inch above soil	Mint in a border	Runners rooting over the rim

For other crops, our pot size guide for vegetables uses the same gallon measures.

Best Pot Material for Mint

Maryland describes peppermint as growing best in rich, moist soil and spearmint in somewhat moist soil. That preference decides the material question, because the main difference between pot materials is how fast they lose water.

Material	How it handles water	Verdict for mint
Plastic, resin or fiberglass	Dries out more slowly than porous pots	Least watering. Pick a light color for full sun
Clay, ceramic, concrete or wood	Porous, dries out more quickly	Workable if you check it daily in summer
Fabric grow bag	Air prunes roots into a denser, fibrous root system	Good root development; check moisture daily like any container

Maryland’s container guide states that containers made from porous materials such as clay, ceramic, concrete and wood will dry out more quickly than containers made from plastic, resin, fiberglass or metal, and that dark container colors can raise the temperature of the potting mix enough to injure tender roots. On a deck in full sun, that argues for a pale plastic or resin pot. Fabric bags get credit in the same guide for better plant growth through air pruning of the roots. A longer comparison is in terracotta vs. plastic vs. fabric pots.

Whatever the material, the pot needs holes or slits that drain excess water. Do not add rocks, gravel or pot shards to the bottom. Maryland notes that a layer like that raises the water table inside the container and leads to waterlogging, a point covered in rocks in the bottom of a pot. Fill the pot with a multipurpose or soil-based potting mix, as the Royal Horticultural Society advises for mint; see potting mix for containers for what to look for.

How to Keep Mint From Escaping the Pot

A pot stops rhizomes at the wall. It does not stop the runners that grow over the rim.

The fix is a pair of scissors. Maryland’s advice is that runners (stolons) can be cut as needed if they try to creep out of the pot. A pot on a patio, deck or paver makes that easy, because a runner that leaves the pot lies in plain view on a hard surface. A pot set on a garden bed or lawn needs a closer look, since soil is right beside the rim. Frequent cutting is no loss. Illinois Extension notes that the more often stems are cut, the more new growth the plant produces.

Some gardeners want mint in a border anyway. The method that extension services describe is a sunk container: remove the base of a plain plastic pot, plant it into the ground, and leave about an inch of the pot above the soil line, according to Maryland. That forces the runners up and over the lip, where they can be seen and trimmed before they root on the other side. The Royal Horticultural Society gives the same reason for leaving the rim slightly above the surface, which is to stop shoots rooting over the top. Utah State University Extension asks for more margin with buried containers: 3 to 4 inches above the soil surface and 10 to 15 inches below it.

Where to Put the Pot and How to Water It

Mint is flexible about light. The Royal Horticultural Society says it is happy in full sun or partial shade, and Maryland adds that peppermint is probably most productive in full sun. A pot in full sun will need more water, so match the site to how often you can check it.

Containers dry out faster than ground soil. Maryland’s advice for all container crops is to check daily in summer and water by need, not by calendar, since frequency depends on pot material, size, location and weather. Utah State adds a limit for mint: it prefers moist soil, but excess water promotes root and leaf diseases. Since pot size is one of the things that sets how often a container needs water, a larger volume of mix is the practical case for buying at the 5-gallon end of the range. More detail is in how often to water container plants in summer.

One Variety Per Pot

Give spearmint, peppermint and any other mint its own container. Maryland spaces mint plants 18 inches apart in the ground, which is wider than the 12 to 16 inch pot, so a single plant is the right load for one container. Two aggressive spreaders in one pot would be competing for the same 2 to 5 gallons of mix.

Starter plants are the simpler way to stock those pots. Utah State notes that mints hybridize readily, so plants grown from seed often fail to be true to type, and it recommends buying established plants, taking cuttings or dividing a plant you know. Maryland lists division and cuttings as the ways to propagate mint. Our guides to herb seeds vs. starter plants and propagating herbs from cuttings in water cover both routes.

When to Repot or Divide Potted Mint

A pot of mint does not last forever. The Royal Horticultural Society says mint should be repotted regularly, typically every few years depending on the size of the container, because of its spreading rhizomes. Illinois Extension suggests dividing plants every 3 to 4 years to keep them vigorous. In a 2-gallon pot expect to reach that point sooner than in a 5-gallon bucket.

To divide, tip the plant out, split the root mass, and replant one piece in fresh potting mix in the same pot. The spare pieces can go into more containers. Keep the spares off bare soil unless you want mint there, since stems and stolon pieces root readily.

Quick Recap

• Buy a pot 12 to 16 inches across, holding 2 to 5 gallons, with drainage holes.
• Plastic and resin pots dry out more slowly than clay. Pick a light color for full sun.
• Stand the pot on a patio, deck or paver, and cut runners that creep over the rim.
• In a border, sink a bottomless pot and leave the rim about 1 inch above the soil.
• Keep one variety per pot and divide every 3 to 4 years.