Ajuga

Sun

Partial shade is ideal. Tolerates full sun where the soil stays moist; provide afternoon shade in hot climates.

Water

Keep evenly moist while establishing. Once rooted, water during prolonged dry spells; avoid persistently wet soil.

Soil

Moist, well-drained soil enriched with organic matter. Tolerates clay if drainage is adequate and accepts acidic to slightly alkaline conditions.

Height

4-8 in / 0.3-0.7 ft (0.1-0.2 m), including flower spikes

Spread

1-2 ft (0.3-0.6 m) initially; rooted runners can eventually cover a much larger area

Flowers

Spring to early summer; usually blue to violet-blue upright flower spikes. Some cultivars have pink or white flowers.

Foliage

Rounded to spoon-shaped leaves in low rosettes. The species is green; cultivars may have bronze, purple or variegated foliage. Evergreen in mild climates, but leaves may die back or become damaged in cold winters.

Growth

Fast in moist soil and partial shade.

Care needed

Medium

• Water newly planted divisions whenever the surface soil begins to dry, until they are well rooted.
• Apply a thin layer of compost in spring; routine fertiliser is rarely needed.
• Keep mulch away from the crowns and avoid burying the rosettes.
• Lift runners that cross border edges before they root into lawns or neighbouring plants.
• Divide crowded patches in spring or early autumn, discarding dead centres and replanting healthy rooted rosettes.

Pruning. After flowering, snip off spent spikes or lightly shear a large patch without cutting into the crowns. Remove winter-damaged leaves in spring and trim escaping runners whenever they appear.

Early spring

Remove damaged leaves and check for rotting crowns.

Spring

Plant or divide healthy rosettes and water them in thoroughly.

Late spring

Remove faded flower spikes after the main display.

Summer

Water during dry spells and lift runners spreading into paths, lawns or neighbouring plants.

Early autumn

Divide congested patches where there is time for roots to establish before winter.

Winter

Keep fallen leaves from smothering the mat and avoid walking on frozen or waterlogged foliage.

• Plant beneath deciduous shrubs to cover bare soil, keeping it clear of small or slow-growing plants.
• Use as a low border edge beside a path, where escaping runners are easy to spot and remove.
• Pair purple-leaved forms with hostas and ferns for contrasting leaf colour and texture.
• Thread through spring bulbs to provide foliage cover after the bulbs finish flowering.

Garden styles it suits: Woodland, Cottage garden, English country, Traditional, Blues and silvers and Pollinator garden.

Plant it with: Hostas, Ferns, Hellebores, Snowdrops, Daffodils and Siberian bugloss.

Wildlife: The flowers provide nectar for bees and other pollinating insects. The dense foliage offers shelter for small invertebrates.

• Crown rot and southern blight: crowns collapse, particularly in warm, wet, crowded conditions. Remove affected plants and nearby debris, improve drainage and thin dense patches; do not divide diseased plants.
• Powdery mildew: pale powdery patches develop on leaves. Improve airflow, reduce crowding and avoid letting plants become severely drought-stressed.
• Slugs and snails: young leaves develop irregular holes. Remove hiding places, hand-pick at dusk or use an approved iron-phosphate bait as directed.
• Leaf scorch and drought damage: leaves brown in hot sun or dry soil. Water deeply and move plants to afternoon shade if damage recurs.

Not known to be toxic to cats, dogs, horses or people; no part is recognised as poisonous. It is not a food plant, and eating garden foliage may still cause stomach upset.

Where it spreads. Spreads aggressively by rooting runners and can invade lawns and neighbouring beds in the United States, United Kingdom, Canada and Australia. It escapes cultivation and is considered invasive in parts of the eastern United States, including Virginia. Keep it away from natural woodland and check local invasive-plant guidance before planting.

• Ground ivy (Glechoma hederacea)

  Ground ivy has rounded, scalloped, aromatic leaves on trailing stems, with flowers arising at the leaf joints rather than in ajuga's upright, crowded spikes.

• Selfheal (Prunella vulgaris)

  Selfheal has short, dense, roughly cylindrical flower heads and leafy upright stems; ajuga has tiered flower spikes rising above a mat of rosettes.

• Upright bugle (Ajuga genevensis)

  Upright bugle lacks the long, rooting surface runners typical of Ajuga reptans and has more conspicuously hairy stems and leaves.

The species name reptans means creeping, referring to the stems that spread along the ground and root.

Propagation. Separate rooted runners or divide healthy clumps in spring or early autumn. Replant at the original depth and keep moist until established. Seed-grown plants may not retain a cultivar's foliage colour.

Accepted botanical name

Ajuga reptans

In the US and Canada

Introduced in Canada and the lower 48 states.

Native range

Albania, Algeria, Austria, Baltic States, Belarus, Belgium, Bulgaria, Central European Rus, Czechoslovakia, Denmark, East European Russia and France.

Measured

Soil pH 3 to 4. Average height 11 cm.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.