The Ajuga reptans [a-JOO-guh ] [REP-tanz ] is a herbaceous flowering plant native to Europe, northern Africa, southwestern Asia, but is invasive in parts of North America.
It’s a part of the Mint family (Lamiaceae).
There are several varieties on the market:
- Black Scallop – Deep blue flower colors.
- Blueberry Muffin – Blueberry-blue flowers, dense attractive rosettes.
- Bronze Beauty – Bronze-tinged leaves with blue flowers.
- Burgundy Glow – Contrasting creamy-white, rose-burgundy, and dark green foliage.
- Catlin’s Giant – Whorls of tiny blue-violet flowers arranged on spikes.
- Ajuga Chocolate Chip – Bluish-purple flower spikes.
Its other common names include:
- Blue bugle
- Carpet bugleweed
- Common bugle
- St. Lawrence plant
Caring for Ajuga Reptans Bugleweed
Size & Growth
The Ajuga Reptans have dark green leaves with a lovely, unique, purplish highlight making a beautiful year-round plant.
As a ground cover, they are dense and fast-growing.
The leaves of the plant grow up to 2″ – 3″ inches.
In spring, the leaves bear tall flower stalks of 4″ – 6″ inches.
The sprawling herb’s stems have a square shape with hair on the two sides.
This bugleweed will spread by stolons (reptans means of creeping) to form a mat-like ground cover.
Flowering and Fragrance
The flower stalks bear many small purple flowers frequently visited by flies like the Rhingia campestris.
The blue flowers have dark veins on the lower lip.
The corolla forms a two-lipped flower around 0.5″ inch long.
The upper lip of the flower is flat and short with a smooth edge.
They begin to bloom in late spring to early summer.
The peak bloom time or blossom period occurs in May and June.
They have no scent in particular but look beautiful in the garden or freshly cut.
Light & Temperature
It will grow in full sun to full shade.
The best foliage color usually occurs in partial shade.
The plant produces more flower spikes in full sun, but the foliage will grow smaller in such a hot climate.
It’s tough deciding to grow in part shade or a shady area compared to the full sun because of the big difference it makes on the plant’s aesthetics.
The plant needs a high temperature of 70° degrees Fahrenheit (21 °C) during planting season to flourish properly.
As a grown plant, it can tolerate much heat but will need a lot of air circulation to prevent crown rot.
Watering and Feeding
The plants need to be watered every 2-3 weeks, and the soil needs to be well-drained.
Keep the soil moist for optimum growth.
The bugle herb doesn’t need much fertilizer to flourish.
When necessary, you may apply an all-purpose granular fertilizer.
Use a water-soluble fertilizer at a ratio of 1 tablespoon to 1 gallon of water.
Soil & Transplanting
The Ajuga Reptan can tolerate a wide variety of soil conditions, but the soil should be well-drained.
The plant prefers to grow in moist soil but is drought tolerant.
The plant thrives in acidic soil with a pH level of 3.7 to 6.5.
Ajuga is usually evergreen to semi-evergreen.
It’s is hardy in USDA Hardiness Zones of 3-9.
You will need to dig up the new runners of the plant to transplant them.
Attempt this when they are young since they become entangled with the parent plant.
Add them to new soil, prepared with mulch so they can grow comfortably.
Grooming and Maintenance
The bugleweed has to be pruned to keep it tidy and maintained.
Around every third year, the crowded groupings should be thinned out so the plant doesn’t become invasive.
This will reduce the chance of crown rots.
Removing non-variegated foliage is important if it appears on the original Ajuga reptan plant.
It will ensure the plant remains colorful and doesn’t revert to a bland green.
How to Propagate Bugleweed
Bugleweed propagates via digging and dividing.
Provide good air circulation to avoid crown root problems.
Dividing clumps is essential by fall or early in the spring season.
The runners are easily removed from the parent plant when they are young and haven’t spread as much.
As they age, it becomes hard to remove the offsets since they become entangled with the mother plant.
You should remove the runners periodically, even to discard them, this will keep the plant contained.
Blue Bugle Pest or Disease Problems
Aphid infestation can affect the health of the plant.
They start to die if the plant gets affected by crown rot from too much entanglement and choking.
Ajugas Reptans spread rapidly like all other mints.
Their rapid growth rate becomes a problem since this is often an invasive trait.
You may need some edging material to keep the plant within the preferred bounds.
It’s a deer-resistant plant.
Suggested Uses for Carpetweed
The carpetweed is adaptable, vigorous plants and useful as ground covers.
They quickly fill bare spots under trees, along garden walks, and tumbling from nooks in rock walls and stone steps.
The common bugle is used for erosion control in many areas for its extensive root system which can prevent soil loss.
Ajuga pairs well with Coralbells, the semi-evergreen lobed foliage ground cover plants, and looks good in rock gardens.