Gingermint (Mentha x gracilis)

Synonyms: Mentha cardiaca, Mentha gentilis, Mentha ?gentilis L. var. cardiaca, Mentha ?muelleriana

Common Names: Redmint, Scotch mint, Scotch spearmint, bushy mint

Description:

Gingermint (Mentha ? gracilis) is an aromatic garden mint ? a naturally occurring hybrid between corn mint (Mentha arvensis) and spearmint (Mentha spicata) ? native to Europe and Asia [2][3]. It was brought to North America in the 1800s as a culinary and medicinal herb and now escapes from gardens into moist, disturbed ground [3]. MISIN tracks it as a non-native plant, though it is a modest spreader: it sets little or no seed and creeps only by its roots [3].

Habit:

Gingermint is a low, aromatic perennial that grows about 1 to 2.5 feet tall on upright, square stems that often carry a reddish tint [3]. Like other mints, its leaves grow in opposite pairs, and the whole plant gives off a strong, sweet-spicy mint smell when crushed ? the easiest way to know you have a mint [3]. Its small violet-to-lavender flowers cluster in tight rings where the upper leaves meet the stem, rather than in a single spike at the top [3]. It spreads into patches from creeping roots [3].

It is easiest to notice in summer, when the plant is in leaf and the little lavender flower rings show along the upper stem [3]. The square, reddish stems, opposite leaves, and strong mint scent identify it as a mint the rest of the season [3].

At-a-glance cues:

1. Upright, square stems with a reddish tint, about 1 to 2.5 feet tall [3]
2. Opposite leaves and a strong, sweet-spicy mint smell when crushed [3]
3. Small violet-to-lavender flowers in tight rings where the upper leaves join the stem [3]
4. Spreading patches rooted from creeping underground stems [3]

Leaves:

1. Arrangement: opposite (in pairs) [3]
2. Shape: oval to lance-shaped, toothed along the edges [3]
3. Surface: green and strongly aromatic when crushed [3]

Stems:

1. Habit: erect, square (four-sided) herbaceous perennial stem, about 1 to 2.5 feet tall [3]
2. Color: green, often with a reddish tint [3]
3. Spread: creeps outward by rhizomes (underground stems) [3]

Flowers:

1. Color: violet to lavender [3]
2. Arrangement: in dense rings where the upper leaves meet the stem [3]
3. Fertility: sterile ? the flowers set little or no viable seed [3]
4. Bloom time: summer [3]

Fruit and seeds:

1. Seed: essentially none ? the hybrid is sterile and rarely if ever sets viable seed [3]
2. Spread instead: entirely by creeping rhizomes and by rooted pieces or cuttings (see Reproduction) [3]

Habitat:

Gingermint grows in moist, disturbed ground and tolerates a range of soils and light levels, from full sun to light shade [1][3]. It is most often found in and near gardens and former garden sites, and it spreads into damp ground along the edges of lakes, ponds, streams, ditches, and yards [3]. It is a naturally occurring hybrid of two Eurasian mints, native to Europe and Asia; it is not native to North America, where it was introduced as a garden herb in the 1800s and now grows across many northern and eastern states [1][2][3].

Reproduction:

Gingermint spreads only by growing, not by seed ? as a sterile hybrid it makes little or no viable seed [3]. Instead it creeps outward on rhizomes (underground stems) that send up new shoots, and any rooted piece ? a runner, a division, or a cutting ? can start a new plant [3]. That is how it leaves a garden: it is planted, then creeps under a fence or is carried in moved soil, plant divisions, or dumped garden waste [3].

Because it spreads by its roots and pieces rather than seed, the key to control is to dig out the whole root system and to avoid moving rooted fragments to new ground [3].

Impact and Damage:

Gingermint is the same aromatic mint grown as a kitchen and tea herb, so it is not toxic to people or pets. For a homeowner, the main issue is that, like most mints, it does not stay put ? it creeps by its roots into lawns, beds, and damp corners and can form spreading patches that are a nuisance to keep in bounds [3].

In natural areas its impact is considered minor. It mostly turns up near gardens and old home sites and in moist, already-disturbed ground rather than overrunning intact natural habitats, and no significant ecological or economic damage has been documented for it [3]. MISIN tracks it mainly to map where this non-native garden plant is spreading [3].

Similar species:

Gingermint is one of many mints, and mints are notoriously hard to tell apart because they hybridize freely. All of them share square stems, opposite leaves, and a minty smell.

Peppermint (Mentha ? piperita) is another escaped hybrid mint with reddish, square stems, but its flowers are usually gathered into a spike at the stem tips rather than in rings along the leaf joints, and its smell is sharp and menthol-cool rather than sweet-spicy [3].

Spearmint (Mentha spicata), one of gingermint's parents, is very similar but carries its flowers in a slender spike at the top of the stem, and has nearly stalkless, sharply toothed leaves and a clean spearmint scent [3].

Corn mint (Mentha arvensis), gingermint's other parent (also called wild mint), also bears its flower rings in the leaf joints, but it sets seed and is fertile, and its scent is different ? telling these mints apart often takes close attention to smell and flower arrangement [3].

Monitoring and rapid response:

Signs to watch for:

1. Patches of upright, square, reddish-tinted stems with opposite leaves and a strong mint smell, near gardens or in damp ground [3]
2. Small violet-to-lavender flower rings along the upper stem in summer [3]
3. Mint spreading under fences or into lawns and beds from a planting [3]

What you can do:

1. Dig out the whole root system while the patch is small ? because gingermint spreads by creeping roots, remove all the rhizomes, not just the tops, or it will regrow [3]
2. Bag and dispose of the dug plants and root pieces rather than composting them or leaving rooted fragments on the soil [3]
3. Smothering a patch with heavy mulch or cardboard, or repeated close cutting, can wear it down over time
4. Don't share or move mint divisions or soil from a patch to new ground [3]
5. Natural area crews can dig scattered patches near old home sites and along damp edges, removing the root mass and returning to catch regrowth [3]
6. Report sightings (below) so its spread can be mapped [3]

When to call a professional:

1. Large or well-established patches, or infestations tangled through other plantings, where digging out the roots isn't practical ? a land manager or licensed applicator can plan a larger approach [3]
2. For chemical control options, contact a licensed applicator or your local cooperative extension office.

Report sightings to MISIN. Help track this species' spread by submitting observations through the MISIN web site or the MISIN mobile app (Android, iOS, Windows, and macOS). Photos at multiple angles paired with a precise GPS location are the most valuable data for confirming new occurrences and triggering rapid-response review.

Credits:

1. USDA NRCS PLANTS Database. Mentha ?gracilis Sole (gingermint). plants.usda.gov
2. Plants of the World Online (Kew). Mentha ? gracilis Sole. powo.science.kew.org
3. U.S. Geological Survey, Nonindigenous Aquatic Species. Mentha ? gracilis (gingermint) ? Species Profile. nas.er.usgs.gov

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