Pronunciation: (Glee-KO-muh hed-ur-AY-see-uh)
• Prostrate perennial herb with square stems to 21/2 feet long
• Hardy in Zones 4 through 9
• Round, scalloped leaves on long stalks
• Small violet flowers in spring
• Leaves once used in medicine and brewing beer
• Tenacious weed; variegated cultivar grown in hanging baskets
Long ago, brewers and herbalists appreciated this indestructible plant with glossy green leaves and pretty violet flowers. Today’s gardeners hate the way it invades lawns and flowerbeds, but a few tolerate its better-behaved variegated form.
The genus Glechoma comprises twelve species of creeping perennial herbs native to Eurasia. They were formerly assigned to the genus Nepeta, the catmints, but are now separated on the basis of technical characters. G. hederacea is well established as a weed throughout much of North America. The name Glechoma is a Greek word once applied to pennyroyal or another member of the mint family. Hederacea means “like Hedera,” a genus of ivy, and refers to this herb’s creeping habit, as do many of its common names: besides creeping Charlie, ground ivy, gill-over-the-ground, runaway Robin, and Lizzie-run-up-the-hedge are just a few of the alternatives.
Creeping Charlie has fibrous roots that form along its square, typical-mint-family stems; as you try to weed it out of your garden, the stems break, leaving rooted bits that readily form new plants. The leaves, shiny green on top, paler below, and arranged in pairs along the stem, are round or kidney-shaped with scalloped edges and are borne on stalks that range from a few inches to a foot long in the most robust plants. The leaves are typically 3/4 to 1 inch across but may reach 2 inches on plants grown in fertile soil. They are evergreen in mild climates.
The flowering stems are somewhat erect, about 8 inches tall, and clothed in fairly small leaves. The flowers, about 3/4 inch long, are borne in threes in the leaf axils in late spring. The violet corollas are two-lipped: the upper lip is small and two-lobed; the lower one has three much larger lobes, the central one largest of all. The flowers are of two kinds, pistillate (having only female reproductive structures) and perfect (having both male and female structures). They are pollinated by bumblebees and flowerflies. The fruit consists of four smooth, ovoid brown nutlets less than 1/8 inch across.
Running the lawn mower over creeping Charlie releases a somewhat astringent odor very different from that of turf grass and nothing like the “minty” or “balsamic” scents that some authors have reported.
After the plants have finished flowering, they start creeping with a vengeance, sneaking under mulches and between specimen plants, working their way into the shadows, growing bigger and fatter as they put down roots into rich garden soil. They make an attractive, maintenance-free ground cover in shady areas where grass won’t grow. Just don’t plan to grow anything else in that area.
Uses for Creeping Charlie
The ancients found many medicinal uses for creeping Charlie. The English herbalist John Gerard reports Dioscorides’s remedy for sciatica “or ache in the huckle bone”: drinking “half a dram of the leaves” in “four ounces and a halfe of faire water, for fourty or fifty days together.” Galen preferred to use the flowers for this purpose and claimed that they, being very bitter, also “remove stoppings out of the liver.” Matthiolus used the juice, mixed with verdigris (a poisonous copper compound), to treat “fistulaes and hollow ulcers.”
Other ills reputedly eased by this herb include ringing in the ears, constipation caused by lead poisoning (“painter’s colic”), kidney disorders, indigestion, coughs, and tuberculosis. Either the dried leaves or the fresh juice might be snuffed up the nose to relieve headaches.
The plants are said to be toxic to horses, whether eaten fresh or dried in hay. Cattle, goats, and swine are said to refuse them.
Few scientific studies of creeping Charlie’s efficacy have been conducted. Animal experiments do not support its use as a cough medicine. A 1986 laboratory experiment showed that ursolic and oleanolic acids from the herb (these constituents are also found in numerous other plants) inhibited the Epstein-Barr virus and protected mouse skin from induced tumor growth. A 1991 study showed that a fatty acid from creeping Charlie stimulated enzyme activity in blood platelets.
English countrywomen commonly added creeping Charlie (which they called alehoof, “hoof” meaning “herb”) to their ale or beer to clarify it and add a bitter flavor. This custom seems to have died out following the introduction of hops to England in the seventeenth century.
Creeping Charlie’s tender young growth, rich in vitamin C, may be eaten like spinach or added to vegetable soup. The herbalist Maud Grieve calls a sweetened tea of the tops “an excellent cooling beverage.” In Europe and perhaps elsewhere, the gall wasp Cynips glechomae can cause the leaves to form big, hairy galls in autumn, which, according to Grieve, “are sometimes eaten by the peasantry of France.”
Growing Creeping Charlie
Creeping Charlie thrives in moist, fertile soil in shade but also tolerates dry, poor soil in sun. Propagate it by replanting root-bearing stem segments.
• Richters, Goodwood, ON, Canada L0C 1A0; (905) 640-6677; www.richters.com. Catalog free. Seeds and dried herb of Glechoma hederacea; plants of G. hederacea ‘Variegata’.