Mondo grass

Sun

Partial shade to full shade; tolerates more sun in cool climates if the soil stays moist. Protect from strong afternoon sun in hot regions.

Water

Water regularly during establishment. Once rooted, it tolerates short dry spells, but grows best with moderate, consistent moisture.

Soil

Moist, well-drained soil enriched with organic matter; tolerates clay if drainage is adequate. Avoid persistently waterlogged ground.

Height

0.5-1 ft (0.15-0.3 m)

Spread

0.5-1 ft (0.15-0.3 m) per clump, gradually forming wider colonies

Flowers

Summer; small white to pale lilac flowers on short stems, often hidden among the leaves, followed by blue berries.

Foliage

Evergreen. Dense tufts of narrow, arching, dark green leaves. Foliage may brown after severe frost or exposure to drying winter winds.

Growth

Slow to moderate; dwarf cultivars spread particularly slowly.

Care needed

Low

• Water new plants whenever the surface soil begins to dry during their first growing season.
• During prolonged dry weather, water deeply rather than giving frequent light sprinkles.
• Apply a thin layer of compost in spring; routine heavy feeding is unnecessary.
• Mulch between young clumps, keeping mulch clear of their crowns.
• Divide congested clumps in spring and replant divisions promptly.

Pruning. In late winter or early spring, remove brown leaves with scissors before new growth starts. If the whole planting is winter-damaged, shear it above the crowns without cutting into emerging shoots; routine mowing is unnecessary.

Late winter

Remove frost-damaged foliage before fresh shoots emerge.

Spring

Plant or divide clumps once the soil is workable and severe frost has passed.

Spring

Top-dress lightly with compost and renew mulch between plants.

Summer

Check soil moisture during dry spells, especially beneath trees and in containers.

Autumn

Remove thick accumulations of fallen leaves that smother the foliage.

Winter

Keep containers draining freely and shelter them from severe freezing winds.

• Edge shaded paths with a continuous ribbon of dark green foliage.
• Plant beneath shrubs and small trees where soil is not extremely dry, creating a low evergreen carpet.
• Tuck between rocks or beside stepping stones to soften hard edges; keep it out of regular foot traffic.
• Pair with broad-leaved shade plants such as hostas and bergenias for contrasting leaf shapes.
• Use in sheltered courtyard containers as an evergreen underplanting.

Garden styles it suits: Japanese, Zen dry garden, Woodland, Modern courtyard, Green on green and Low-maintenance.

Plant it with: Hostas, Japanese painted ferns, Bergenias, Camellias, Japanese maples and Hellebores.

Wildlife: The dense foliage provides shelter for small invertebrates. Flowers and berries offer some wildlife interest, but this is not a major nectar or wildlife food plant.

• Root or crown rot in waterlogged soil: improve drainage, reduce watering and remove badly affected clumps.
• Slugs and snails chewing young foliage: remove hiding places, hand-pick after dark or use a labelled iron-phosphate bait.
• Brown leaf tips from drought, strong sun or drying winds: water deeply and provide afternoon shade or shelter.
• Yellowing and weak growth in deep, dry shade: improve soil moisture and move plants if tree-root competition is too strong.

Not known to be toxic to cats, dogs or horses. Evidence on human ingestion is limited; do not treat the berries or other parts as food. Eating plant material may still cause stomach upset.

• Big blue lilyturf (Liriope muscari)

  Usually taller and coarser, with broader leaves and conspicuous upright purple flower spikes above the foliage; its ripe berries are dark purple-black rather than blue.

• Creeping lilyturf (Liriope spicata)

  Spreads much more vigorously by runners, usually has broader leaves and carries pale flower spikes more visibly above the foliage.

• Black mondo grass (Ophiopogon planiscapus 'Nigrescens')

  Has purple-black rather than green mature leaves, generally broader than those of ordinary mondo grass.

Ophiopogon comes from Greek words meaning 'snake' and 'beard', while japonicus means 'of Japan'.

Propagation. Divide rooted clumps in spring, keeping roots and several shoots on each division. Species plants can also be raised from cleaned, fresh seed, but germination and growth are slow; divide named cultivars to preserve their characteristics.

Accepted botanical name

Ophiopogon japonicus

Native range

China North-Central, China South-Central, China Southeast, Japan, Korea, Philippines, Taiwan and Vietnam.

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