How to Grow Japanese Forest Grass
Hakonechloa macra
Hakonechloa is a graceful, slow-growing grass forming cascading mounds of arching foliage. Plant in partial to full shade in moist, humus-rich soil. It is slow to establish but long-lived and trouble-free once settled. Cut back old foliage in early spring before new growth appears. Turns beautiful shades of copper and pink in autumn.
Yearly Lifecycle
Care Essentials
Mulch with leaf mould or compost in spring. A light feed of general-purpose fertiliser helps on poor soils but avoid overfeeding.
Watch For
- Slugs on young spring growth
- Scorching in full sun or dry conditions
- Very slow growth in first 2 years (be patient)
Track your Japanese Forest Grass care schedule — pruning, feeding, and seasonal tasks
Start planning freeCare Requirements
☀️ Light
Partial shade to full shade — essential
Hakonechloa requires shade to perform well. Dappled shade under deciduous trees is ideal. Full sun causes leaf scorch and a ragged, stressed appearance.
💧 Watering
Regular — does not tolerate drought
Keep the soil consistently moist throughout the growing season. Mulch annually with leaf mould to retain moisture and improve soil structure.
🌱 Fertilizing
Light spring feed on poor soils; mulch preferred
A top-dressing of leaf mould or compost in spring is usually sufficient. On very poor soils, a light balanced feed in April helps.
✂️ Pruning
Cut back to ground level in early March
Remove all old foliage in early spring before new growth emerges. The papery old stems can be pulled away by hand or cut with shears at ground level.
❄️ Overwintering
Fully hardy; leave old foliage through winter
Hakonechloa is fully hardy in UK conditions. Leave the old foliage in place over winter — it provides crown protection and attractive winter structure.
Growing Tips
Patience pays off
Hakonechloa is famously slow to establish — it may barely move in year one or two. By year three it starts to fill out, and by year five it forms the beautiful cascading mound it is known for. Do not move or divide it prematurely.
Shade is preferred, not just tolerated
Unlike most ornamental grasses, hakonechloa actively prefers dappled shade or partial shade. Full sun will scorch the leaves and cause the plant to look ragged, especially in summer.
Keep moisture consistent
This grass needs reliably moist, humus-rich soil. It does not tolerate drought. Incorporate plenty of leaf mould or compost at planting and mulch annually to retain moisture.
Autumn colour is a highlight
In autumn the foliage of most cultivars turns beautiful shades of copper, pink, and burgundy before dying back. Leave the old foliage through winter as it adds structure and protects the crown.
Pests & Diseases
Pest Slug
Identification: Ragged holes and shredded edges on new spring growth; slime trails visible in the morning.
- Apply nematode biological control in moist soil above 5°C.
- Scatter ferric phosphate slug pellets around the plant base in spring.
- Ferric phosphate pellets (wildlife-safe alternative to metaldehyde).
Pest Vine Weevil
Identification: Notched leaf margins from adult feeding; C-shaped grubs at the root zone causing collapse.
- Apply Steinernema kraussei nematodes to moist soil in autumn.
- Imidacloprid compost drench for container-grown plants.
Disease Leaf Scorch Abiotic (sun/drought stress)
Symptoms: Brown, bleached tips or whole blades turning straw-coloured, especially in summer.
Treatment: Move to a shadier position or increase watering. Cut back scorched foliage and allow to regrow.
Prevention: Plant in partial shade with reliably moist, humus-rich soil. Mulch annually to retain moisture.
Disease Grass Rust Puccinia spp.
Symptoms: Orange-brown powdery pustules on leaf blades, usually in late summer.
Treatment: Remove and dispose of affected blades. Improve air circulation.
Prevention: Avoid overhead watering in the evening. Cut back hard in early spring to remove overwintering spores.
Log Japanese Forest Grass in your garden — track growth, care, and harvests year after year
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