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.
|Common Name||Bugleweed, common bugleweed, ajuga, carpet bugle, blue bugle, carpetweed, carpenter's herb|
|Botanical Name||Ajuga reptans|
|Plant Type||Herbaceous perennial|
|Mature Size||6 to 9 in. tall and 6 to 12 in. wide|
|Sun Exposure||Full sun to partial shade|
|Soil Type||Medium-moisture, well-drained|
|Soil pH||Slightly acidic 6.5|
|Bloom Time||May to June|
|Flower Color||Blue, violet|
|Hardiness Zones||4 to 9 (USDA)|
|Native Area||Europe, northern Africa, southwestern Asia|
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.
Bugleweed has been reported as an invasive plant in Maryland, West Virginia, and Oregon.
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.
Bugleweed prefers medium moisture, well-drained soils with a good amount of organic matter. It will tolerate moderately dry soil.
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.
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 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.
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:
- Dig up the entire mother plant and surrounding offshoot plants.
- Separate the plant clumps into individual plants by hand or with a sterilized sharp knife.
- Discard brown or withered plants.
- 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:
- Fill small pots with a seed-starter mix.
- Cover the seeds with a thin layer of compost and keep moist but not soggy; They will sprout within a month.
- When the seedlings are viable, pot them up into larger containers.
- Once robust, transplant the seedlings into the garden.
Common Pests & 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.
What companion plants can I grow with bugleweed?
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.
Does bugleweed have a scent?
Although the blue flowers are prominent, they don't have any fragrance.
Is bugleweed deer-resistant?
Bugleweed is deer-resistant. It tastes very bitter and bad to most animals, except the muskrat, which likes to nibble on the roots.
Ajuga Bugleweed. University of Arkansas Division of Agriculture.
Aggressive Plants in the Landscape. Iastate.Edu.
Carpet Bugle (Invasive Plant Atlas of the United States). University of Georgia Center for Invasive Species and Ecosystem Health and National Park Service.
Marsden, Christy. “Southern Blight.” Wisconsin Horticulture, https://hort.extension.wisc.edu/articles/southern-blight/