Mint is a rapid growing perennial herb with many varieties that grow up to 3 feet tall and are quite invasive. Mint grows best in full sun to partial shade, should be planted early in the growing season and is generally hardy to -20° F. Mint prefers moist soil conditions, but excess water will promote root and leaf diseases. Harvest leaves and stems throughout the season, or cut back within an inch of the ground about three times a season, just before the plant blooms.
Use care when selecting mint varieties. The taste and smell varies greatly between varieties. For cold areas of Utah, peppermint, spearmint, and woolly mints are very hardy. All varieties are well suited to areas of Utah with more mild winters. Culinary varieties include those listed above and those with mint-like flavors including red raripila mint, ginger mint (redmint), horsemint, and pineapple mint. Mints widely used in teas and medicinal preparations include watermint, corn or field mint, and pennyroyal.
Is Mint Invasive in the Garden? How to Enjoy This Useful Herb Without Letting It Take Over
Mint is one of the most popular herbs for home gardeners. With its fresh aroma and flavor, mint adds delight to teas, cocktails, desserts, and more. However, mint’s vigorous spreading habit can quickly turn this useful plant into a nuisance if left unchecked.
In this article, we’ll explore why mint tends to be invasive, look at which types spread most aggressively, and discuss effective ways to control mint so you can enjoy its benefits without it taking over your garden
Why Mint Spreads So Readily
All mint varieties (part of the Mentha genus) spread rapidly via underground stems called rhizomes. As the rhizomes creep horizontally beneath the soil surface, they send up new leafy shoots. A small starter patch of mint can eventually colonize a very large area through this creeping root system.
Mint’s rhizomes can spread several feet outward in all directions each year. Their growth is difficult to control because new shoots pop up unpredictably and any fragments left behind can resprout into new plants. This invasive spreading trait makes mint hard to eliminate once it gets established.
Most Invasive Mint Species
While all mints spread via rhizomes, some specific varieties are more aggressive colonizers. Spearmint (Mentha spicata), apple mint (Mentha suaveolens), and creeping water mint (Mentha aquatica) are notoriously invasive. Peppermint (Mentha x piperita) spreads readily too, though a bit less forcefully.
Even small stem pieces or crushed leaves of these mints can easily take root. Their lightweight seeds also allow the plants to spread well beyond their original sites.
Can Mint Take Over My Garden?
If left alone, invasive mint types certainly can take over sizable portions of a garden. However, with careful planting methods, mint can be grown without it running amok:
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Plant mint in large containers sunk into the ground to restrict root spread. Use containers with drainage holes.
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Surround containers with vertical barriers like buried metal sheeting or pool liner to contain roots.
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For in-ground planting, sink a bottomless bucket or other barrier around the mint to contain it.
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Isolate mint patches from other beds. Avoid planting mint near vulnerable areas.
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Remove flowering stems to prevent self-seeding.
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Aggressively prune mint’s top growth and dig out expanding rhizomes.
Controlling Invasive Mint
If mint has already escaped its bounds, here are effective control techniques:
Manual Removal – Dig up all visible mint plants, removing as much of the roots and rhizomes as possible. Repeat to control regrowth.
Smothering – Smother small mint patches with mulch, yard waste or weighted tarps to block light and kill the plants.
Solarizing – Solarize larger infestations under clear plastic in hot, sunny weather to bake and kill the plants/roots.
Herbicides – Apply a glyphosate herbicide like Roundup to mint leaves in late summer/fall, avoiding nearby plants. Re-treat regrowth.
Landscape Barriers – Install durable barriers like sheet metal, heavy duty pond liner or commercial root barriers around mint beds. Bury barriers 8-12 inches deep.
Growing Mint Successfully
With proper control methods, you can enjoy mint’s scent and flavor without it running wild:
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Choose less aggressive mints like gingermint, pineapple mint or orange mint.
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For invasive types, use containment suited to your garden’s size and layout.
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Monitor mint patches frequently, removing unwanted expansion.
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Harvest mint often for cooking and share it with other gardeners.
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Plant mint in mixed beds with shallow-rooted, short-lived neighbors you don’t mind replacing more often.
A versatile, fragrant herb, mint can be grown successfully even in smaller gardens with some diligence. A bit of extra care will allow you to reap mint’s benefits without its aggressive spreading habit ruining the rest of your garden. With routine maintenance to keep it in check, mint can be a delightful addition to both your landscape and recipes.
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Mint is a rapid growing perennial herb with many varieties that grow up to 3 feet tall and are quite invasive. Mint grows best in full sun to partial shade, should be planted early in the growing season and is generally hardy to -20° F. Mint prefers moist soil conditions, but excess water will promote root and leaf diseases. Harvest leaves and stems throughout the season, or cut back within an inch of the ground about three times a season, just before the plant blooms.
Use care when selecting mint varieties. The taste and smell varies greatly between varieties. For cold areas of Utah, peppermint, spearmint, and woolly mints are very hardy. All varieties are well suited to areas of Utah with more mild winters. Culinary varieties include those listed above and those with mint-like flavors including red raripila mint, ginger mint (redmint), horsemint, and pineapple mint. Mints widely used in teas and medicinal preparations include watermint, corn or field mint, and pennyroyal.
Problems with Growing Mint
Mint is best planted in containers or where roots are confined. Mint spreads quickly in open garden areas and will out-compete most garden plants. Once established it is very hard to eradicate.
Most diseases can be minimized or eliminated by appropriate watering and ensuring proper sunlight to plants. Consider drip irrigation as an excellent method to provide regular water and keep foliage dry. As the mint grows and multiplies, thinning or dividing may be essential to maintain healthy plants.
Insects |
Identification |
Control |
|---|---|---|
| Aphids | Green or black soft-bodied insects that feed on leaves. Foliage curls, yellows or becomes stunted. | Use insecticidal soaps, registered insecticides or spray plant with a forceful jet of water to dislodge the insects. |
| Flea Beetle | Small, shiny black beetles that chew tiny holes in leaves. | Control with registered insecticides or cover plants in spring with row covers. |
| Cutworm | Larvae feed at or below ground and sever stems of seedlings or plants. | Protect individual plants with a collar or trap, use registered insecticides. |
Disease |
Symptom |
Control |
| Anthracnose | Small water soaked spots on leaves and stems. | Rotate planting areas, remove diseased plants, and prune healthy plants to the ground in fall. |
| Mint Rust | Small whitish, slightly raised spots that turn reddish orange or brown on underside of leaves. | Avoid wet leaves overnight. Use drip irrigation or apply overhead water before mid-day. |
| Verticillium Wilt | Leaf yellowing starting at the margin and they eventually curl up and die. | Rotate planting areas, remove infected plants, and do not over fertilize plants. |
MINT GROWING GUIDE: Conquer the Challenges of Mint!
FAQ
Why shouldn’t you plant mint in your garden?
Mint spreads quickly by underground runners known as rhizomes and can quickly take over a garden bed and out-compete nearby plants. If you want the mint in the ground, plant it in a container with the bottom removed to contain the runners.
How do I keep mint from spreading in my garden?
Mulching: Apply a thick layer of mulch (3-4 inches) over the affected area to block sunlight and prevent mint from growing back. Cardboard or Newspaper: Lay down cardboard or several layers of newspaper over the mint and cover with mulch. This will smother the plants.
How invasive are mint plants?
Mint (and many of its relatives) are notoriously invasive. We’ve planted it in large pots, but it requires constant vigilance because it keeps trying to escape. It easily roots along its stem, so as it grows and sprawls, it will set roots into any soil it touches.
Does mint strangle other plants?
Planting mint in a raised garden bed is unwise because mint is an extremely invasive plant with a robust root system that spreads quickly and aggressively. In the confined space of a raised bed, mint can easily overtake other plants, competing for nutrients, water, and sunlight, and eventually choking them out.