Ajuga Bugleweed: Perennial Ground Cover

Simply transplant from the pot into a hole somewhat larger than the pot, wider but not deeper. Add a bit of compost or a basic fertilizer. Be gentle getting the plant out of the pot, in fact, destroy the pot if you have to, rather than hurt the plant. Loosen the roots by pulling them carefully apart at the base. This helps them spread into the soil more rapidly. Place the plant in the hole so that what was the surface of the soil in the pot is the surface of the soil in the ground. Fill in with soil, pressing down firmly. Plant ajugas 12” apart to have a series of plants, as close as 6” to have them fill in rapidly as a ground cover. Water transplants thoroughly and keep them moist for the first growing season.

How to Grow and Care for Bugleweed

David Beaulieu is a landscaping expert and plant photographer, with 20 years of experience.

Debra LaGattuta is a Master Gardener with 30+ years of experience in perennial and flowering plants, container gardening, and raised bed vegetable gardening. She is a lead gardener in a Plant-A-Row, which is a program that offers thousands of pounds of organically-grown vegetables to local food banks. Debra is a member of The Spruce Garden Review Board.

Cherisse Harris is a fact-checker with a focus on lifestyle, beauty, and parenting. She’s worked in research for nearly two decades.

Bugleweed (Ajuga reptans) is a fast-growing herbaceous perennial ground cover (the species name reptans means creeping) that does a good job of choking out weeds. It produces shiny, dark green leaves and beautiful flower spikes, producing blue, violet, or purple flowers in mid- to late-spring that can reach eight to ten inches tall, although the flower spikes on some cultivars are shorter. Several cultivars offer variegated foliage colors and patterns. Plant bugleweed in the late spring or early summer.

Bugleweed spreads via stolons, runners that take root at points along its length to form new plants which enables it to quickly overrun its planting area. Bugleweed spreads quite aggressively so plant it where it won’t creep into other areas of your garden or lawn.

Bugleweed Care

Bugleweed can make quite a nuisance of itself through its aggressive spreading via underground runners (called stolons), but there are a few situations in which its good qualities will be enough reason for some gardeners to grow it.

The plant excels at filling in large, shady areas where lawns are difficult to grow, and it can work well on banks or slopes or planted around trees and shrubs. It looks especially attractive within rock formations. Bugleweed is also used as erosion control in many areas because its extensive root system can prevent soil loss. It forms a dense mat that will displace weeds.

Bugleweed has an unusual character in that it is so tough that it can even grow under black walnut trees (Juglans nigra), which produces a chemical that discourages most plants.

However, avoid planting bugleweed near lawn areas because it can quickly spread into turf grass. Plant bugleweed in an area where air circulation is good, spacing the plants about one foot apart.

Warning

Bugleweed has been reported as an invasive plant in Maryland, West Virginia, and Oregon.

Light

Bugleweed does well in full sun to part shade locations. Foliage color is most vibrant when the plant receives at least three to four hours of sunlight daily.

Soil

Bugleweed prefers medium moisture, well-drained soils with a good amount of organic matter. It will tolerate moderately dry soil.

Water

Bugleweed prefers moist soil, so while new plants are becoming established, give them one to two inches of water per week including rainfall. Once established, plants can tolerate some dryness but one inch of water per week should be sufficient. Water whenever the top one to two inches of soil becomes dry.

Temperature and Humidity

Bugleweed does well in a wide range of temperatures, but in very hot, humid areas, it requires good air circulation to prevent crown rot.

Fertilizer

Feeding is rarely necessary unless the plant is growing in poor soil. When it is needed, apply an all-purpose granular fertilizer. Or, use a water-soluble fertilizer at a rate of 1 tablespoon per 1 gallon of water. Morning feeding is best, and make sure to rinse off any fertilizer granules from the leaves.

Types of Bugleweed

• A. reptans ‘Atropurpureum’ has bronze-purple foliage.
• A. reptans ‘Chocolate Chip’ has darker leaves than the species plant, including a hint of chocolate brown.
• A. reptans ‘Burgundy Glow’ has burgundy tri-colored variegated foliage (white, pink, and green).
• A. reptans ‘Dixie Chip’ is another variety with tri-color variegated foliage (creamy-white, deep-rose, and green) and produces a mat that grows 2 to 4 inches tall.
• A. reptans ‘Black Scallop’ has perhaps the darkest foliage of all the cultivars with almost-black, scalloped leaves, and deep blue flower spikes. It produces a mat that grows 3 to 6 inches tall. The darkest foliage color is achieved when plants are located in full sun.

Pruning

Pruning helps to keep bugleweed under control. Rigorously prune runners twice a year. Be sure to remove any runners escaping the desired planting area. In addition, cut off the flower spikes in late summer after the flowers have faded. To shear back a large area of bugleweed, use a lawnmower set to a high blade height.

If the planting area becomes crowded, thin out the plants in the fall by digging up the entire clump and replanting half of the roots. To control it in your garden beds, stay vigilant about pulling it out from where it doesn’t belong or it will gain a toehold and become a nuisance.

Propagating Bugleweed

Bugleweed is one of the easiest plants to propagate by division. This is best done in spring or fall when there is no chance of frost. Bugleweed spreads by underground runners that form new plants around the parent plant. When the plant colonies become overcrowded or are spreading too aggressively, dig them up, divide and transplant them. Here’s how:

1. Dig up the entire mother plant and surrounding offshoot plants.
2. Separate the plant clumps into individual plants by hand or with a sterilized sharp knife.
3. Discard brown or withered plants.
4. Plant the individual plants in new locations.

Growing Bugleweed From Seed

Bugleweed plants are easy to grow from seed. Start seeds indoors in the early spring. Here’s how:

1. Fill small pots with a seed-starter mix.
2. Cover the seeds with a thin layer of compost and keep moist but not soggy; They will sprout within a month.
3. When the seedlings are viable, pot them up into larger containers.
4. Once robust, transplant the seedlings into the garden.

Common Pests and Plant Diseases

Mostly free of pests and diseases, the only insect that truly likes bugleweed is the aphid, which can be sprayed off the plant with a garden hose.

The other common problem bugleweed could encounter is crown rot, a soil-borne disease that can affect overcrowded plants with poor air circulation. In the South, crown rot is also called Southern blight, and it is caused by a fungus (Sclerotium rolfsii). This is a problem in humid areas or when the plant is growing in heavy soils. You can prevent crown rot by planting in well-drained soil. If plants succumb to the fungus, they will quickly wilt and die.

You’ll find plenty of companion woodland plants for bugleweed that grow well in partial or full shade. For example, pair with coral bells, daffodils, violas, forget-me-nots, astilbe, and hardy geraniums. For extra greenery, plant hostas and ferns.

Although the blue flowers are prominent, they don’t have any fragrance.

Bugleweed is deer-resistant. It tastes very bitter and bad to most animals, except the muskrat, which likes to nibble on the roots.

The Spruce uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

1. Ajuga Bugleweed. University of Arkansas Division of Agriculture.
2. Aggressive Plants in the Landscape. Iastate.Edu.
3. Carpet Bugle (Invasive Plant Atlas of the United States). University of Georgia Center for Invasive Species and Ecosystem Health and National Park Service.
4. Marsden, Christy. “Southern Blight.” Wisconsin Horticulture, https://hort.extension.wisc.edu/articles/southern-blight/

Ajuga Bugleweed: Perennial Ground Cover

You’ve Probably Seen Ajugas Without Noticing Them. They Form a Lovely Ground Cover.

Ajuga is the scientific name, but it is also the common name I use. Other common names are bugleweed, bugle, bugleherb, carpetweed, carpenter’s herb, variations on those names, and St. Lawrence plant. You do have to be mindful not to confuse ajugas with another plant called bugleweed, Lycopus species, which grows taller and used in herbal medicine.

Bugle might loosely describe the flower shape or be an old mispronunciation of ajuga. Americans add weed or herb to the name; since a bugle is a musical instrument, it feels more complete and clearer to make the longer name. European sources tend to say just bugle. Carpetweed describes its spreading, ground cover growth form. “Weed” doesn’t mean it is a problem plant; weed seems to have meant “a plant I don’t know any use for” as in joe-pye weed and fireweed when people named it. Carpenter’s herb seems to be a variation of carpetweed (or vice versa) and nobody knows why in some places ajuga is called St. Lawrence plant.

There are more than 40 Ajuga species worldwide, native to Eurasia, Africa, and Australia, but not the Americas. They are in the mint plant family, Lamiaceae, and have the square stems and flowers shaped like broad spearmint flowers that are common in that family. The ajuga most commonly grown as a cultivated plant is common bugleweed or creeping bugle, Ajuga reptans, but Italian bugle, Ajuga tenorei, and blue bugle or carpet bugle Ajuga genevensis, and hybrids, are also available. Two other species, yellow bugle or ground pine Ajuga chamaepitys, and upright or pyramid bugle, Ajuga pyramidalis appear in the USDA’s plants of the United States data base, and, being native to Eurasia, probably were cultivated years ago.

Common bugleweed, Ajuga reptans, stands out as a ground cover, explaining its popularity. It grows less than six inches high, with leaves two to six inches long. Without flowers, the plant lies practically on the ground, the leaves covering the ground all around it. The leaves are shiny and can be in colors from deep green to violet to rich reds and oranges, solid or patterned, creating a dramatic patch of ground, neatly covered in leaves.

Ajugas spread on short rhizomes, so a plant becomes a clump, a clump becomes a bed of ajugas. They are good enough at invading that you may have to pull them out of the adjacent lawn. I find them easy to uproot but persistent—”in the rose garden again.” They are not on any U.S. noxious weed list I could find, but are included on several weed watch lists because they spread so well. Out of caution, some places will not allow them to be imported, for example, Hawaii, Puerto Rico, and Canada.

When they flower, in May and June, creeping ajugas send up a flower stalk of deep blue mint-like flowers, generally under 6” tall but capable of reaching 10” in a really good year. When an area where ajuga is the dominant plant comes into bloom, it turns the dramatic and beautiful color of the flowers, since each small plant sends up its own flower stalk. The flowers don’t have noticeable scent to humans but are attractive to flies, bees, and butterflies. If you look closely, you will see that the flowers are monoecious: some flowers on each plant have pollen on stamens, some don’t but have stigmas for receiving pollen.

As a group, the varieties of Ajuga reptans are hardy from USDA Zone 3 to 10. Different varieties are listed as, say, Zones 4-8, so pay attention to hardiness for a particular variety. They are evergreen; the leaves remain on the plant and maintain their color all winter.

The meaning of the name Ajuga is unclear. Gerard’s Herbal in 1633 listed ibigo, aiuga, and abiga as names used for the plant in Latin. You can look those up in Latin dictionaries and find a variety of possible meanings. Linnaeus in 1754 chose Ajuga for the scientific name. So, Romans called it aiuga/ajuga, but we aren’t sure why. The species epithet reptans means creeping.

Where to Plant Ajugas

Plant them as ground covers in partial shade to full sun. They will survive some foot traffic but not heavy trampling. Set them along a wall, edge, or paved area to soften the look. Try them in areas where it has been hard to establish any plants, such as on slopes. Reportedly they will grow under walnut trees, which most plants will not. They can be used as a groundcover under a line of shrubs. They spread rapidly to cover the ground and are dense enough to choke out weeds. They can be elegant in containers, for example each container with an ajuga with a different color of leaves.

More specifically, they are described as growing from full sun to full shade. The foliage color will be the best in three to four hours of sunlight. In warm climates, on a site with intense full sun, the leaves may scald. In my yard, they have nearly died out in deep shade and are expanding in relatively sunny spots. That all adds up to saying they are hardy and tolerant, but, in your yard, may do better in some spaces than others.

Put ajugas into well-drained soil, but beyond that they are not picky. They like a moderate amount of moisture but will endure dry periods. A slightly acidic soil grows them well, although they survive a wide range of soils. Ajugas favor soils with substantial organic matter but they don’t require it. Do provide good circulation in areas of high humidity. That will reduce mildew, to which they are susceptible.

They are heat- and cold-tolerant; no special protections required.

They do spread, so planting them along walks or driveways or surrounding them with an edging will keep them from invading flower beds and lawns.

How to Plant Ajugas

Simply transplant from the pot into a hole somewhat larger than the pot, wider but not deeper. Add a bit of compost or a basic fertilizer. Be gentle getting the plant out of the pot, in fact, destroy the pot if you have to, rather than hurt the plant. Loosen the roots by pulling them carefully apart at the base. This helps them spread into the soil more rapidly. Place the plant in the hole so that what was the surface of the soil in the pot is the surface of the soil in the ground. Fill in with soil, pressing down firmly. Plant ajugas 12” apart to have a series of plants, as close as 6” to have them fill in rapidly as a ground cover. Water transplants thoroughly and keep them moist for the first growing season.

You can easily divide existing plants to expand the planting. Many varieties self-seed and spread that way.

Maintaining Ajugas

Once established, they need little care. A light fertilization with a low nitrogen fertilizer in the spring, perhaps, and supplemental water in a dry period. Periodic thinning will rejuvenate a stand.

If you plant a hybrid with a dramatic leaf pattern or color, you will want to pinch off new growth that is not your chosen color. By spring, last year’s leaves are pretty battered, but the new spring leaves will spread over them, no maintenance required. Removing old flower stalks will reduce self-seeding and make the flowerbed look better sooner, but old flower stalks wither, drop off, and vanish in a month or so if you don’t remember to cut them off.

Pests and Diseases

Ajugas are deer resistant. They are technically edible to humans (new shoots, young leaves) but too bitter to be pleasant. This same bitterness discourages rabbits.

Generally, ajugas have little trouble with insects since they left most of their pests behind in Eurasia. Aphids are the most common problem and can be washed off with a garden hose.

Ajugas are susceptible to mildew, so are more satisfactory in drier locations. To reduce the chance of mildew, plant them in areas with good air circulation and avoid over-watering them.

Blue Bugle and Italian Bugle

Italian bugle (Ajuga tenorei) and blue bugle (Ajuga genevensis) are also attractive garden plants. They too spread and will beautifully fill an area. They are just a little taller than creeping bugle, blue bugle to 12” high, for example, so are not as easily used as ground covers. Plant them along a wall or in a dramatic stand. Both Italian bugle and blue bugle hybridize easily with creeping bugle so nurseries have created many low-growing hybrids, making an even broader array of colors and textures available from ajugas.

The scientific name for Italian bugle is variously given Ajuga tenori, A. tenorii, and A. tenorei online. Only Ajuga tenorei appears in lists of accepted species names. It is from the mountains of Italy and is rare in the wild. Apparently, it was named after its discoverer, the Italian botanist Michele Tenore, (1780-1861), making Ajuga tenorei the right spelling, since that says “Tenore’s ajuga” in Latin.

Blue bugle is the Geneva ajuga, the species epithet genevensis means “of Geneva, Switzerland.”

Cover problem areas with ajugas for a low-maintenance splash of bright color.

By Kathy Keeler

About the writer: I have gardened all my life, in New York, Ohio, California, Nebraska, and Colorado; the differences fascinate me. My B.S. (biology) is from the University of Michigan, my Ph. D. (genetics) from the University of California, Berkeley. For 31 years I was professor of Biological Sciences at the University of Nebraska-Lincoln, studying plants. In retirement, I traveled and saw wonderful plants; now I write a blog (AWanderingBotanist.com) to share plant stories.