Stipa gigantea, giant feather grass
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Grasses & Grass-like

Stipa gigantea

giant feather grass

Poaceae

Iberian Peninsula — Spain and Portugal; dry rocky hillsides, scrub, and open pine woodland. Synonym: Celtica gigantea

At a Glance

TypeGrass
HabitClumping
FoliageEvergreen
Height2-3 feet (60-90 cm) foliage clump; 5-8 feet (150-240 cm) in bloom
Width3-4 feet (90-120 cm)

Growing Zones

USDA Hardiness Zones

6 - 9
Zone 6
Zone 7
Zone 8
Zone 9
These zones indicate the coldest temperatures this plant can typically survive.
Frost Tolerancehardy

Key Features

Deer Resistant
Drought Tolerant
Maintenancevery low

Overview

A large, clump-forming evergreen ornamental grass in the family Poaceae, native to the dry rocky hillsides, scrub, and open pine woodland of the Iberian Peninsula (Spain and Portugal). Also known under the synonym Celtica gigantea. The base forms a dense, arching clump 2–3 feet (60–90 cm) tall and wide of narrow, rolled, dark green to gray-green leaves 18–24 inches (45–60 cm) long. In June through July, slender flowering culms rise 5–8 feet (150–240 cm) tall bearing enormous, open, airy panicles 12–18 inches (30–45 cm) long of pendant, oat-like florets with long, twisted, glistening silver-gold awns. The panicles catch and transmit light with exceptional effect — backlit in afternoon sun, they glow gold and amber. The dried culms and panicles persist through fall and winter, providing months of continued structural and light-catching interest. RHS Award of Garden Merit. Non-toxic.

Native Range

Native to dry rocky hillsides, open scrub, and pine woodland of the Iberian Peninsula (Spain and Portugal), growing in well-drained, poor, often calcareous soils in full sun.

Suggested Uses

Planted as a specimen or focal point in mixed borders, Mediterranean-style gardens, and gravel gardens at 4–5 foot (120–150 cm) spacing — allow significant space for the flowering culms. Outstanding positioned where afternoon light can backlight the golden panicles. Highly effective against dark hedging, stone walls, or dark architectural elements. Pairs well with cistus, lavender, and salvia. One of the most architecturally dramatic ornamental grasses for temperate gardens.

How to Identify

Identified by a basal clump of narrow, arching, dark green rolled leaves 18–24 inches (45–60 cm) tall, and extraordinarily tall flowering culms 5–8 feet (150–240 cm) rising from early June carrying huge, open, airy panicles of pendant oat-like florets with long glistening silver-gold awns. No other commonly cultivated ornamental grass produces flowering stems of this height from such a compact base clump. The synonym Celtica gigantea is used in some botanical references.

Appearance

Size & Dimensions

Height2' - 8'
Width/Spread3' - 4'

Colors

Flower Colors

gold
silver
yellow

Foliage Colors

green
gray

Fall Foliage Colors

no change

Bloom Information

Bloom Period

~8 weeks
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Summer
Flowering culms emerge from May and open fully in June through July. The dried panicles persist on the plant in excellent condition through fall and winter — 6–8 months of ornamental interest from a single flowering. The panicles are most dramatic in late afternoon light when backlit by low sun, causing the long awns to glow silver-gold. Old culms can be left until early spring when they begin to deteriorate.

Detailed Descriptions

Flower Description

silver-gold; enormous open airy panicles 12–18 inches with pendant oat-like florets with long twisted glistening awns; backlit they glow gold and amber

Foliage Description

narrow, rolled, dark green to gray-green; arching clump 18–24 inches tall; semi-evergreen in cold winters

Growing Conditions

Sun Requirements

Full Sun
Requires 6-8 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 8.0(Neutral)
357912
Soil Types
sandchalkrockyloam
Drainage
well drained

Water & Climate

Water Needs

Very Low

Frost Tolerance

hardy

Time to Maturity

2-3 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Plant in full sun in very well-drained, lean to average, neutral to slightly alkaline soil with a pH of 6.0–8.0. Excellent drainage is critical — the evergreen clump is susceptible to crown rot in wet, poorly drained soils in winter. Tolerates drought and poor soils once established. Allow at least 4–5 feet (120–150 cm) of space for the flowering culms. In the Pacific Northwest, a south or west-facing position with good drainage is ideal. No regular division needed — clumps are long-lived if drainage is adequate.

Pruning

Leave the flowering culms and panicles through fall and winter — their persistence is a major ornamental asset. Cut old culms to the base in late winter (February–March) before new growth begins. Do not cut into the green foliage clump; the evergreen leaves should remain unless badly frost-damaged. Division is rarely needed; if the center dies, lift and replant outer sections in early spring.

Pruning Schedule

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early spring

Maintenance Level

very low

⚠️ Toxicity Warning

Non-toxic