Ajuga (Bugleweed)

How to choose an ajuga

Choose by leaf colour and by how much ground you need to cover. Catlin's Giant (Ajuga reptans 'Catlin's Giant') has the largest leaves, bronze-purple and up to 15cm long, on a mat about 30cm high and 80cm across, with tall blue spikes, so it covers the most ground per plant. Purple leaf bugle is the classic dark form at about 15cm. Chocolate Chip is the smallest, a 10cm mat of narrow chocolate-brown leaves for between pavers and at the front of a border. Burgundy Glow mixes cream, pink and burgundy in each leaf and brightens a shady spot, and Tuff n Tidy is a compact, tough green-bronze selection. The austral bugle (Ajuga australis) is the Australian native, a clumping plant to 25cm with soft green leaves and purple-blue flowers, for native and bush gardens.

Where ajuga works

Part shade to full shade, with morning sun giving the best leaf colour and flowering; in hot afternoon sun the leaves scorch. It is the plant for the ground under trees and shrubs, the shaded side of a house, slopes that need holding, the gaps between stepping stones, and the front of a woodland or cottage border. Ajuga grows in every capital city and takes the frosts of Canberra and the tablelands without complaint; in Brisbane and the subtropics plant it in the coolest, shadiest ground you have and expect it to rest through a humid summer. It belongs with our other groundcover plants and the plants in plants for partial shade.

Planting and spacing

Plant in autumn or spring into soil improved with compost, and mulch lightly between plants until they close over. Space Catlin's Giant 40cm to 50cm apart, the mid-sized forms 30cm, and Chocolate Chip 20cm to 25cm; at those spacings a bed is covered in one growing season. Water twice a week through the first summer. Ajuga spreads by surface runners, so a mowing strip or a path edge keeps it where you want it.

Care basics

Once established ajuga needs water only in long dry spells, a light feed in spring, and the spent flower spikes trimmed or mown off in late spring to keep the mat tidy. Lift and replant rosettes from the edge of a clump to fill gaps or start a new area; they root within weeks. Crown rot can strike in wet, humid conditions with poor airflow: thin the mat and improve drainage. Our guide to ground cover plants for shade places ajuga among the alternatives.

Common questions

Is ajuga invasive?

It spreads by runners within a bed and can creep into a lawn, but it is not a declared weed in Australia and is easily pulled. Edge the bed and it stays put.

Does ajuga grow in full sun?

In cool climates with moist soil, yes. Elsewhere the leaves scorch in afternoon sun; morning sun and afternoon shade is the ideal.

Can ajuga handle foot traffic?

Light, occasional traffic between stepping stones, yes. It is not a lawn substitute for a path that is walked every day.

When does ajuga flower?

Spring, with spikes of blue or purple-blue flowers 15cm to 30cm tall for several weeks. Bees and native bees visit them heavily.