Purple moor-grass
Molinia caerulea · Poaceae
📷 Elke Freese · CC BY-SA 3.0
The gardener's calendar
Purple moor-grass is in full bloom: enjoy it, watch watering in hot weather and let spent flowers feed pollinators before pruning.
ID card
- Scientific name
- Molinia caerulea
- Family
- Poaceae (grass)
- Foliage
- Deciduous
- Flowering
- August to September
- Adult height
- 120 cm
- Hardiness
- Very hardy (-20°C)
- Growth
- Moderate
- Origin
- Temperate Europe and Asia
✓ Taxonomy verifiedSource: AI estimate · hardiness: reliability high.
Expert tips
The key tip
Molinia thrives in acidic, moist soil. Plant in drifts for visual impact; it tolerates partial shade but produces its best flowering spikes in full sun.
The common mistake
Planting it solo or in dry, chalky soil: it stays stunted and undersized.
The pro's trick
Leave the flowering spikes up all through autumn and winter: they turn russet-gold and create beautiful winter structure.
Seasonal watch
September-October: in very humid climates, thin out the center of the clump in autumn to prevent basal rot over winter.
Care
Exposure
Molinia appreciates full sun or partial shade for optimal development. It tolerates sunny locations well, which enhance the golden colorations of its foliage in autumn. Light shade can work, but sunlight promotes a denser and more compact form.
Watering
Water regularly during the first year to establish the root system well. Once established, molinia tolerates dry periods well thanks to its deep roots. In summer, check soil moisture and water if the ground becomes too dry, particularly on poor soils.
Soil
Molinia prefers well-draining and rather acidic soils. It adapts to poor and even damp terrain, making it ideal for gardens in difficult conditions. Avoid dense limestone or poorly-draining soils that may slow its growth.
Pruning and cutting
Cut molinia back to ground level in late winter or early spring, before new growth begins. This rejuvenates the clump and promotes beautiful flowering. You can keep the dried inflorescences in autumn for a winter landscape effect before cutting.
Fertilizer
Molinia is undemanding for fertilizer and thrives on poor soils. An application of compost or organic matter in spring is more than sufficient. Avoid overly rich fertilizers that could promote excessive foliage development at the expense of flowering.
Diseases and pests
Molinia is a very robust grass, rarely affected by diseases or pests. Poor drainage or prolonged water stagnation can cause root rot. Ensure good air circulation to prevent any health problems.
Did you know?
Molinia caerulea gets its name from the Latin 'caeruleus' (blue), an allusion to the bluish tint its spikelets take on during flowering before turning golden. Appreciated for a long time by contemporary gardeners, it is one of the most reliable and permanent ornamental grasses in the French garden.
Where to buy it
Plant in spring or early autumn, avoiding spells of intense heat. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, April, May, September.
Add this plant to my garden →Plants from the same family
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- Creeping soft-grassHolcus mollis
- Rough reedgrassCalamagrostis arundinacea
Tips generated and checked by Viridia — adapt them to your local climate.