Description of Ophiopogon japonicus (Mondo Grass)

Ophiopogon japonicus is mondo grass, a low evergreen with narrow leaves. It’s not a true marginal, but it works well on the drier top edge of a bog garden where the soil stays damp rather than flooded.

Appearance

It forms dense tufts of dark green, grass-like leaves. In summer it can produce small pale flowers followed by blue-black berries. It usually sits around 15 to 25cm tall, so it stays neat.

Care Guide

It’s easy as long as you don’t drown it and you keep weeds out of the clump.

• Sun: Part shade to sun. Shade is fine, but growth is slower.
• Soil: Moist but free-draining soil with organic matter.
• Water: Damp soil suits it. Avoid standing water over the crown.
• Feeding: A spring mulch of compost is usually enough.
• Division: Split clumps in spring if they get congested.

If you grow it near the wettest zone, plant it slightly raised so the crown stays above waterlogged compost.

Suitability for Bog Garden

This suits the upper edge of a bog garden, where you want a tidy, evergreen border line. It also looks good beside stones and paths because it stays compact.

Use it as a repeat plant to tie sections together, or as a low base under taller plants that die back in winter.

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