The world of Glechoma hederacea, commonly known as ground ivy, creeping charlie, alehoof, and a host of other names.

What Makes it So Special (or Infamous!) Glechoma hederacea is a plant that evokes strong reactions. Gardeners either love their tenacious ground-covering abilities or curse their aggressive spread. Here is the crux of its "specialness":

• Vigorous Growth: It is incredibly good at spreading, both by creeping stems (stolons) that root at the nodes and by seed. This makes it an excellent ground cover in some situations, but a highly invasive weed in others.
• Adaptability: It tolerates a wide range of conditions, from sun to shade, moist to relatively dry soils, and various soil pH levels. This adaptability contributes to its success (and its potential to become a problem).
• Aromatic Foliage: The leaves have a distinctive, minty-sage-like aroma when crushed, a characteristic of the mint family (Lamiaceae) to which they belong.
• Early Spring Blooms: It produces small, pretty, purplish-blue flowers in early spring, providing an early nectar source for pollinators.
• Edible/medicinal: Leaves are edible, high in vitamin C and can be used raw or cooked. It has a long history in traditonal medicine.

Description and Details

• Growth Habit: A low-growing, creeping perennial herb. It forms dense mats of foliage.
• Stems: Square stems (typical of the mint family), rooting at the nodes where they touch the ground.
• Leaves: Opposite, rounded to kidney-shaped, with scalloped or crenate margins (rounded teeth). They are typically 1-3 cm in diameter, but can be larger in shady, moist conditions. The leaves are often slightly hairy and have a noticeable aroma when crushed.
• Flowers: Small, funnel-shaped, bilaterally symmetrical (two-lipped), and purplish-blue to lavender. They appear in whorls in the leaf axils (where the leaf joins the stem) in spring and early summer.
• Fruit: Four small nutlets (seeds) contained within the dried calyx (the sepals that enclose the flower).
• Size: Typically grows to a height of 5-20 cm (2-8 inches), but its spread can be indefinite.

Native Habitat

• Origin: Native to Europe and southwestern Asia.
• Naturalized Range: It has been widely introduced and naturalized in many parts of the world, including North America, Australia, and New Zealand.
• Typical Habitats: It thrives in moist, shady areas such as woodlands, along streams, and in disturbed areas like gardens, lawns, and roadsides. It prefers rich, loamy soils but can adapt to a variety of soil types.

Landscaping Design Tips Here's where careful consideration is crucial:

• Use with Caution: Given its aggressive nature, it is best used in areas where its spread can be controlled or is desired. Never plant it near natural areas where it could escape and outcompete native flora.
• Controlled Ground Cover: It can be effective as a ground cover in shady areas where other plants struggle to grow, such as under trees or shrubs.
• Container Planting: A safer option is to grow it in containers, hanging baskets, or raised beds where its spread is physically limited.
• Edging: If planted in the ground, install deep edging (at least 6 inches, ideally more) to help contain it. This edging should be regularly checked to ensure stems are not escaping.
• Alternatives: Consider less aggressive ground covers if you are concerned about its invasiveness. Some alternatives for shade include:
• Ajuga (Bugleweed) - some varieties are aggressive, but many are well-behaved.
• Asarum (Wild Ginger) - native to many areas and slow-spreading.
• Tiarella (Foamflower) - native to North America, with attractive foliage and flowers.
• Pachysandra terminalis (Japanese Spurge) - evergreen, but also potentially aggressive in some regions.
• Vinca minor (Periwinkle) - another vigorous spreader, so needs careful consideration.

Planting and Care

• Planting:
• Timing: Spring or fall is the best time to plant.
• Spacing: Space plants 12-18 inches apart, as they will quickly fill in.
• Soil: Prefers moist, well-drained soil rich in organic matter.
• Light: Tolerates full sun to full shade but performs best in partial shade.
• Care:
• Watering: Keep the soil consistently moist, especially during dry periods. It can tolerate some drought once established, but growth will be less vigorous.
• Fertilizing: Generally, it does not require much fertilization, especially if grown in rich soil. A light application of compost in spring can be beneficial.
• Pruning/Maintenance: Regular trimming or mowing can help keep it in check. Remove any unwanted runners promptly.
• Pest and Diseases: Generally, pest and disease resistant. Slugs and snails may occasionally nibble on the leaves.

Removal

• Repeatedly pulling or hoeing can be done but must remove all portions of the roots and stems.
• Smothering with cardboard or thick layers of mulch can be done but will require months to fully kill the plant.
• Broad-spectrum herbicides containing glyphosate can be used but use as a last resort. Follow all instructions, avoid run-off, and consider the impact on non-target plants.

Taxonomy

• Kingdom: Plantae
• Phylum: Tracheophyta
• Class: Magnoliopsida
• Order: Lamiales
• Family: Lamiaceae (Mint family)
• Genus: Glechoma
• Species: Glechoma hederacea
• Synonyms: A lot of synonyms, including Nepeta glechoma Benth., Nepeta hederacea (L.) Trevis.

Morphology

• Root System: Fibrous root system with stolons (above-ground, creeping stems) that root at the nodes.
• Stem: Square, as is typical of the Lamiaceae family. Stems are often purplish, especially in sunny locations.
• Leaves: Opposite, petiolate (with a leaf stalk), rounded to reniform (kidney-shaped), with crenate (rounded teeth) margins. Venation is palmate (veins radiating from a single point).
• Flowers: Zygomorphic (bilaterally symmetrical), with a two-lipped corolla. The upper lip is two-lobed, and the lower lip is three-lobed. Stamens are didynamous (two long and two short).
• Fruit: Four nutlets (small, one-seeded fruits) enclosed within the persistent calyx.

Other Insights for Gardeners

• Variegated Cultivars: There are variegated cultivars available, such as 'Variegata', which have leaves with creamy-white margins. These are often less aggressive than the species but can still spread.
• Medicinal Uses (Historical): Glechoma hederacea has a long history of use in traditional medicine for treating various ailments, including respiratory problems, inflammation, and digestive issues. However, it is important to note that this information is for historical context and should not be taken as medical advice. Consult a healthcare professional before using any plant for medicinal purposes.
• Culinary Uses: Young leaves can be used as a pot herb or in salads, adding a slightly minty-sage flavor. It was historically used to clarify and flavor beer before the widespread use of hops (hence the name "alehoof"). Again, use in moderation.
• Invasive Status: It is considered an invasive species in many regions, particularly in North America. Check your local regulations before planting.
• Confused with other plants: It is sometimes misidentified, so check multiple identification points. Other plants include Common Mallow, Henbit, Purple Deadnettle, and Persian Speedwell.

In conclusion, Glechoma hederacea is a fascinating plant with a complex relationship with gardeners. Its vigorous growth, adaptability, and attractive features make it a tempting ground cover, but its invasive potential demands careful planning and management. By understanding its characteristics and employing appropriate strategies, you can decide whether this plant has a place in your garden or if it is best to choose a less assertive alternative.