Autumn moor grass
Sesleria autumnalis. Family Poaceae. Ornamental grass.
Autumn moor grass is a compact, clump-forming perennial grass with yellow-green leaves and airy, silvery flower spikes in late summer and autumn. Grow it for soft edging, repeated mounds through borders or a low ground layer beneath open-canopied trees. Its foliage often lasts through winter, although cold or exposed conditions can leave it brown.
At a glance
- Sun
- Full sun to partial shade; light afternoon shade is helpful in hotter areas.
- Water
- Water regularly while establishing. Once established, it tolerates moderately dry soil, but benefits from watering during prolonged drought.
- Soil
- Well-drained soil with average fertility, including loam, chalk and clay that does not stay waterlogged. Tolerates neutral to alkaline conditions.
- Height
- 1-2 ft (0.3-0.6 m), including flower stems
- Spread
- 1-2 ft (0.3-0.6 m)
- Flowers
- Late summer to autumn; narrow, silvery-white flower spikes age to pale tan.
- Foliage
- Narrow, arching yellow-green to light green leaves form dense, rounded tussocks. Evergreen to semi-evergreen, depending on winter conditions.
- Growth
- Moderate
- Care needed
- Low
Care
- Water newly planted clumps when the soil begins to dry during their first growing season.
- Avoid sites that remain wet through winter; improve drainage before planting.
- Apply a thin layer of compost in spring if growth is weak; avoid heavy nitrogen feeding.
- Keep mulch clear of the crown to reduce trapped moisture.
- Divide congested clumps in spring when the centre becomes thin or growth declines.
Pruning. In late winter or early spring, comb out dead leaves and remove old flower stems. If foliage is badly winter-damaged, trim it to about 3-4 in (8-10 cm) before fresh growth develops; do not routinely scalp healthy evergreen clumps.
Through the year
- Late winter
- Check for winter damage and remove loose, dead foliage.
- Early spring
- Remove old flower stems and trim badly browned leaves before new growth advances.
- Spring
- Plant new clumps or divide established ones; water divisions thoroughly.
- Summer
- Water young plants during dry spells and established plants during prolonged drought.
- Late summer
- Leave emerging flower spikes intact for their pale colour and fine texture.
- Autumn
- Leave sound foliage and seedheads standing; clear heavy accumulations of fallen leaves from the crowns.
In the garden
- Repeat along paths or border fronts to make a low, soft-edged rhythm.
- Plant in drifts between coneflowers, salvias and other upright perennials to link their separate clumps.
- Use beneath open-canopied deciduous trees where there is light shade and enough soil moisture for establishment.
- Combine with dark evergreen shrubs or clipped hedges so the pale foliage stands out.
- Use in well-drained gravel borders for a fine-textured contrast to broad leaves and stone.
Garden styles it suits: New perennial (prairie), Low-maintenance, Dry gravel garden, Modern, Woodland and Green on green.
Plant it with: Purple coneflower, Wood sage, Autumn stonecrop, Bigroot geranium, Japanese anemone and Christmas fern.
Wildlife: Dense clumps offer shelter for small invertebrates. The flowers are wind-pollinated rather than a nectar source for bees or butterflies.
Problems to watch for
- Crown or root rot in persistently wet soil: improve drainage or move the plant to a better-drained position.
- Brown or scorched leaves during prolonged drought: water deeply and consider light afternoon shade in hot gardens.
- Sparse growth and fewer flowers in deep shade: move to a brighter position.
- An open or declining centre in an old clump: lift and divide in spring, replanting the healthy outer sections.
Safety
Not known to be toxic to cats, dogs, horses or people, and no particular plant parts are recognised as poisonous. Species-specific toxicity information is limited; ornamental planting should not be treated as confirmation of suitability for horse forage.
Easily confused with
Blue moor grass (Sesleria caerulea)
Usually has distinctly blue-green foliage and short, dark flower heads in spring, rather than yellow-green foliage and pale late-season spikes.
Blue-green moor grass (Sesleria heufleriana)
Has darker blue-green foliage and conspicuous dark flower heads in early spring; autumn moor grass flowers much later.
The name
Sesleria honours the Italian physician and botanist Leonardo Sesler, while autumnalis and the common name refer to its late-season flowering.
Propagation. Divide clumps in spring, keeping roots and several growing shoots on each division. It can also be raised from seed sown in containers in autumn or spring; germination may be uneven.
Checked against open data
- Accepted botanical name
- Sesleria autumnalis
- Native range
- Albania, Greece, Italy and Yugoslavia.
Sources: GBIF (CC BY 4.0) and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.
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