How to Care For Ajuga Reptans (Bugleherb Plant – Bugleweed)

Last Updated on October 19, 2023 by Plant Mom Care

Bugleweed (or Ajuga reptans), a fast-growing perennial, grows well as ground cover and helps prevent erosion and weeds.

It grows 6 – 9 inches tall and 6 – 12 inches wide, producing glossy dark green oval leaves with beautiful spikes of flowers of purple, blue, or violet that often reach 8 – 10 inches high. Several cultivars have shorter flower spikes, with some having variegated leaves. 

These plants are spread by horizontal runners that often take root along their length, forming new plants that can quickly grow beyond their planting area because of this aspect, plant them where they can’t creep onto other spots in your garden or lawn. Several US states have declared this plant to be invasive.

While this aggressive spreading can be a deterrent to cultivating it, it does have some qualities for which some gardeners plant it – it is excellent for filling up large, shaded areas, on slopes or banks, or planted near trees and shrubs or in rock gardens. 

It is frequently used to control erosion as its far-reaching root system forms a dense mat that helps prevent soil loss and displace weeds. 

Light Requirements

These plants do well under full sun to partially shaded locations, although foliage colors are more vibrant when the plant gets a daily dose of 3 – 4 hours of full sun.

Watering

They prefer moist soil, so give them 1 – 2 inches of weekly watering when new plants are getting established. Once they’re established, reduce watering to 1 inch of weekly watering. 

Humidity

Overly humid conditions in very hot areas require adequate air circulation to avoid crown rot. Very arid conditions can damage the crown, creating suitable conditions for diseases to infect the plants. Proper management of watering practices, humidity, and air circulation will help reduce the incidence of disease pathogens.

Temperature

Maintain temperatures of around 65° F when new plants are getting established. Once they’re established, keep daytime temperatures at 55 – 70°F and nighttime temperatures at 55 – 60°F. 

Soil

These plants grow well in moist, well-draining soils amended with compost although they can endure moderately dry soil.

Repotting

These plants look good in containers or hanging baskets where they can spill over the pot’s edges. Choose a well-draining container and add a layer of rough gravel to help with drainage and prevent drain holes from getting blocked with soil. 

Remove your plant from the old container by gently lifting and removing it. Use your fingers to loosen the feeder roots near the root ball. Add a little soil to the rough gravel. Set the root ball inside the container and add soil so the crown will sit ½ – 1 inch lower than the container’s rim. Water thoroughly, adding more soil if it settles too much after watering.

Propagation

This plant is easily propagated by division or seeds. This is better done in spring or autumn. This plant spreads through runners that produce new plants near the parent plant. When the plants get overcrowded or start spreading too much, dig the plant up, divide and transplant the clumps. 

Propagation by division

Dig the entire mother plant up including the surrounding offshoots. Separate the plants into individual clumps using a trowel or your hands. Prune away any dead or withered stems and roots. Plant the individual clumps in the garden or containers.

Propagation from Seed

This plant doesn’t have seed pods – the seeds from under the calyx resemble small dark brown nuts; each flower produces four seeds. Harvest the seeds after the flowers fade and die and when the seeds become mature.

Start planting seeds in early spring in small pots filled with seed-starting mix, covering the seeds with some compost and keeping them moist but not water-logged.

They will germinate in a month or so, each seedling having somewhat hairy lobed leaves. When the seedlings grow at least 4 inches tall, transplant them into larger containers. When growth is more robust, transplant them in the garden or containers.

Additional Care

Feeding is seldom necessary except if the plant grows in poor soil. If necessary, use a balanced granular fertilizer or a fertilizer that is water soluble and diluted at a ratio of 1 tablespoon for 1 gallon of water. Feeding the plant in the morning is best – wash off any fertilizer that falls on the leaves.

Pruning is necessary to keep these plants under control. Severely prune the runners twice annually to prevent them from escaping their designated planting area. Cut off flower spikes when the flowers fade in late summer. To prune a large area, it’s better to set a lawnmower at a high blade height to save time.

If their planting area gets overcrowded, thin the plants in autumn by digging up entire clumps and removing half the roots. To control its spread in garden beds, be vigilant and pull out runners from spreading elsewhere or the plant will become an invasive nuisance.

Common Problems

These plants are largely free from pests or diseases. Aphids like to attack plants and can be sprayed off with water or insecticidal soap to control and eliminate them.

The other problem the plant might suffer from is crown rot, a fungal infection that affects overcrowded plants in humid conditions and poor air circulation. Crown rot is also called Southern blight in southern US states. 

This disease can be prevented by planting in well-draining soil and pruning to promote air circulation. If the plants are infected by the fungus, they will rapidly wilt and die.