Anemanthele lessoniana (Gossamer Grass): Complete Grass Growing Guide
Anemanthele lessoniana
Anemanthele lessoniana (Gossamer Grass) (Source: wikimedia)
1. Introduction & Taxonomy
Anemanthele lessoniana, the Gossamer Grass, is one of New Zealand's most graceful and garden-worthy native grasses, prized for its flowing, arching habit and the way its fine foliage shifts from green to amber, copper, and reddish tones through the seasons. This elegant tussock-forming grass produces delicate, airy inflorescences that seem to float above the foliage like gossamer threads caught in the breeze. Hardy, adaptable, and visually captivating year-round, it has become one of the most popular ornamental grasses in contemporary landscape design worldwide.
Anemanthele lessoniana forms a graceful, arching tussock typically 60 to 90 cm tall and equally wide, composed of numerous fine, wiry leaves that cascade outward in a fountain-like habit. The narrow leaves, only 2 to 3 mm wide, emerge bright green in spring and gradually develop warm orange, copper, and reddish-brown tones as the seasons progress, with the most intense coloration occurring in fall and winter. In late summer, the plant produces an abundance of delicate, open panicles of tiny spikelets on hair-thin stems that extend above the foliage, creating a shimmering, hazy effect. The entire plant moves fluidly in the slightest breeze, making it one of the most kinetic and textural grasses in cultivation.
Taxonomic Classification
Habitat and Distribution
Endemic to New Zealand, where it grows naturally in forest margins, bush clearings, rocky outcrops, and steep banks in the North Island and the northern half of the South Island. It is typically found from sea level to about 900 meters in partial shade to full sun.
Botanical Note: Poaceae (the grass family) is one of the largest and most ecologically important plant families, with over 12,000 species worldwide. True grasses have hollow, jointed culms (stems), narrow leaves with parallel veins and a distinctive ligule where the blade meets the sheath, and flowers reduced to spikelets arranged in panicles, racemes, or spikes. Ornamental grasses from this family are prized for their graceful movement, feathery inflorescences, and seasonal colour changes.
Native Range & Distribution Map
The map below shows the native range and notable cultivation regions for Anemanthele lessoniana.
2. Biology & Morphology
<\!-- SIZE_COMPARISON_SVG -->Growth Form & Architecture
Anemanthele lessoniana is a tussock-forming true grass (Poaceae) that develops dense, mound-like clumps of foliage with hollow, jointed culms.
Species-Specific Morphology
Anemanthele lessoniana forms a graceful, arching tussock typically 60 to 90 cm tall and equally wide, composed of numerous fine, wiry leaves that cascade outward in a fountain-like habit. The narrow leaves, only 2 to 3 mm wide, emerge bright green in spring and gradually develop warm orange, copper, and reddish-brown tones as the seasons progress, with the most intense coloration occurring in fall and winter. In late summer, the plant produces an abundance of delicate, open panicles of tiny spikelets on hair-thin stems that extend above the foliage, creating a shimmering, hazy effect. The entire plant moves fluidly in the slightest breeze, making it one of the most kinetic and textural grasses in cultivation.
Inflorescence & Flower Structure
Grass flowers are highly reduced and arranged in spikelets, with wind pollination as the primary reproductive strategy.
Key Characteristics
- Height: 0.5-2m
- Growth Habit: Tussock-forming
- Growth Rate: Moderate under optimal conditions
- Life Cycle: Perennial
- Toxicity: Not known to be toxic to humans or pets. It is not grazed by stock due to its wiry texture but poses no toxicity risk.
- Conservation Status: Not Threatened in New Zealand. It is common and widespread in suitable habitats across the North Island and northern South Island.
3. Reproduction & Propagation
<\!-- PROPAGATION_METHODS_SVG -->Primary propagation methods for Anemanthele lessoniana: Seed or vegetative division.
Propagating Anemanthele lessoniana
Anemanthele lessoniana is easily raised from seed, which germinates readily without pretreatment. Sow seed on the surface of a free-draining seed-raising mix, press gently, and keep moist at 15 to 20 degrees Celsius. Germination typically occurs within 14 to 28 days. Seedlings grow relatively quickly and can be planted out after one season. Division is also possible in spring; carefully lift the tussock, separate outer portions with roots attached, and replant immediately. Avoid dividing the central crown, which may not recover well.
Vegetative Propagation
Propagated by clump division in spring or early summer.
Propagation Tip: Division of established clumps in spring gives the fastest results.
4. Cultivation Requirements
<\!-- CULTIVATION_SVG -->Soil / Substrate
Well-draining, moderately fertile soil. A mix of garden loam, compost, and coarse sand.
Watering
Low to moderate; once established, it is quite drought tolerant but performs best with occasional deep watering during extended dry periods.
Light Requirements
Full sun to partial shade. Most ornamental grasses perform best in full sun with at least 6 hours of direct light daily.
Temperature
- Optimal Growth: 18-30°C (65-86°F)
- Minimum Tolerance: -34°C (-30°F)
- USDA Hardiness: Zones 4-9
Fertilization
Apply a balanced slow-release fertilizer in spring. Most grasses are light feeders.
Common Cultivation Mistake: Over-watering and over-fertilizing promote weak, floppy growth. These plants prefer lean conditions.
Seasonal Care Calendar
Follow this season-by-season guide for optimal care timing throughout the year.
🌱 Spring (March–May)
Comb or rake out dead foliage from the base of the tussock. This is preferable to hard cutting, which the plant resents. Divide if needed.
☀️ Summer (June–August)
Water during prolonged dry spells. Enjoy the emerging inflorescences and developing color changes in the foliage.
🍂 Fall (September–November)
The foliage reaches its most vibrant copper and red tones. Leave the plant untouched to appreciate the full color display.
❄️ Winter (December–February)
The plant is semi-evergreen and retains much of its foliage. No pruning needed; simply remove any individual dead leaves by hand.
5. Diseases & Pests
Below are the most common pests and diseases affecting Anemanthele lessoniana and how to manage them.
Crown rot
In poorly drained soils or humid climates, the central crown can succumb to fungal rot, causing the center of the tussock to die out while the outer portions remain healthy.
Leaf tip browning
Exposure to harsh, drying winds or extreme heat can cause the fine leaf tips to brown, though this is largely cosmetic and does not harm the plant.
Aphids
Small aphid populations may occasionally infest developing inflorescences but rarely cause significant damage to established plants.
IPM: (1) Choose the right species for your conditions. (2) Maintain good air circulation. (3) Cut back dead foliage in late winter. (4) Most ornamental grasses are remarkably pest-free when well-sited.
6. Indoor Growing Guide
Anemanthele lessoniana can be grown in containers and brought indoors during winter in cold climates.
Container Selection
Use containers with adequate drainage holes. Terra cotta pots provide good drainage and stability.
Indoor Light
Place in the brightest available location. Most grasses need at least 4-6 hours of direct or bright indirect light.
Indoor Success Key: Bright direct light is the single most important factor for growing grasses indoors.
7. Landscape Use & Design
Anemanthele lessoniana provides graceful movement, fine texture, and seasonal interest in the landscape.
Design Applications
- Mass planting for textural groundcover
- Mixed perennial borders
- Contemporary and minimalist garden design
- Underplanting beneath trees
- Coastal gardens
- Container planting
Companion Planting
These species pair well with Anemanthele lessoniana in garden settings:
- Phormium tenax
- Libertia grandiflora
- Carex testacea
- Astelia chathamica
- Agapanthus praecox
- Heuchera 'Palace Purple'
Design Principle: Ornamental grasses are at their most magical when backlit by low sun. Position where morning or evening light illuminates inflorescences from behind.
8. Cold Climate Strategies
Anemanthele lessoniana shows good cold tolerance and can be grown outdoors year-round in many temperate climates.
Hardiness Thresholds
- USDA Zones: 4-9
- Minimum Survival Temperature: -34°C (-30°F)
Overwintering Options
- Leave in Place (hardy species): Cut back dead foliage in late winter. Apply 5-10 cm of mulch around the crown.
- Container Culture: Move potted plants to a frost-free location for winter.
- Mulching: Apply thick straw or bark mulch over the crown after the first hard frost.
Winter Survival Rule: Most grass losses occur from wet cold. Ensure excellent drainage through winter.
Winter Care Tip: The plant is semi-evergreen and retains much of its foliage. No pruning needed; simply remove any individual dead leaves by hand.
9. Ethnobotany & Cultural Significance
In its native New Zealand, Anemanthele lessoniana holds a place in Maori traditional knowledge as a component of native bush margins and forest clearings. The Maori name is not widely recorded, but the plant is recognized as an indicator species for forest edge habitats. In contemporary horticulture, it has achieved international acclaim and is widely used by leading garden designers, particularly in the New Perennial and naturalistic planting movements championed by designers such as Piet Oudolf. It has received the Royal Horticultural Society's Award of Garden Merit, cementing its status as one of the premier ornamental grasses.
Conservation Note: Many grass, sedge, and rush species play critical ecological roles as habitat providers, soil stabilizers, and water filtration agents. By growing Anemanthele lessoniana, you contribute to maintaining awareness of these often-overlooked botanical workhorses.
Did You Know?
- Gossamer Grass is the sole species in the genus Anemanthele and was formerly classified as Stipa arundinacea and Oryzopsis lessoniana.
- The foliage color change is triggered by cooler temperatures and increased UV exposure, making plants in full sun and cooler climates develop the most vivid coppery tones.
- Despite its delicate appearance, this grass is remarkably tough and can tolerate wind, drought, poor soils, and temperatures well below freezing.
- It was named in honor of Pierre-Adolphe Lesson, a French pharmacist and naturalist who collected plants in New Zealand in the 1820s.
Frequently Asked Questions
Can Gossamer Grass be hard cut back?
Unlike many ornamental grasses, Anemanthele lessoniana does not respond well to hard cutting to the ground. Instead, comb out dead material with a rake or your fingers, and remove individual dead leaves.
Does it self-seed?
Yes, it can self-seed readily in mild, moist climates. In some regions (parts of Australia and the UK), it has naturalized from garden plantings. Remove seedheads if self-sowing is a concern.
What soil does it prefer?
It is adaptable to a wide range of soils, from sandy to clay, as long as drainage is reasonable. It performs best in moderately fertile, well-drained soil.
Is it frost hardy?
Yes, it is hardy to approximately minus 10 to minus 15 degrees Celsius (USDA zones 7-10) and tolerates frost without significant damage.
Summary & Key Takeaways
Anemanthele lessoniana, is a tussock member of the genus Anemanthele (Poaceae), native to New Zealand. It shows good cold tolerance, making it suitable for temperate gardens.
Key Points to Remember:
- Propagation: Seed or clump division
- Light: Full sun for most species
- Substrate: Well-draining, moderately fertile
- Watering: Moderate — avoid overwatering
- Hardiness: USDA Zones 4-9, minimum -34°C (-30°F)