Marlborough Wheatgrass
Anthosachne sacandros
A native wheatgrass forming upright clumps, bearing narrow leaves and wheat-like seed heads. Naturally occurs in dry, open habitats with lean, free-draining soils. Excellent for dryland restoration and low-input gravel plantings. grasses .
Plant Description
Perennial tussock; culms erect; inflorescences wheat-like spikes with glumes/lemmas often awned. Leaves narrow, often glaucous in dry sites. Seed heads offer strong seasonal lines and movement in wind.
Quick Facts
| Scientific Name | Anthosachne sacandros |
|---|---|
| Family | Poaceae |
| Form | Upright tussock; wheat-like spikes |
| Light | Full sun |
| Soil | Lean, free-draining; gravelly or sandy soils ideal |
| Water | Low; drought-tolerant once established |
| Height | 40-60 cm |
| Spread | Clump-forming to 40-60 cm |
| Water Needs | Low to moderate; free-draining soils |
| Frost Tolerance | High - tolerant of severe freezes |
| Salt Tolerance | Low to moderate |
| Growth Rate | Slow to moderate |
| Lifespan | Long-lived perennial |
Climate Best Suited to
Dry, sunny districts with high light and airflow; avoid heavy, fertile soils.
Regional Suitability
| City | Climate Suitability |
|---|---|
| Auckland | Ideal |
| Wellington | Ideal |
| Christchurch | Ideal |
| Dunedin | Ideal |
| Whangārei | Suitable |
| Hamilton | Suitable |
| Tauranga | Suitable |
| Rotorua | Suitable |
| Gisborne | Suitable |
| New Plymouth | Suitable |
| Napier | Suitable |
| Whanganui | Suitable |
| Palmerston North | Suitable |
| Nelson | Suitable |
| Invercargill | Suitable |
Plant Habitat
Strictly confined to the Marlborough region, this species inhabits open sites on limestone bluffs, cliffs, and river terraces from sea level up to 900 meters altitude. It shows a strong preference for high-light environments with skeletal, free-draining soils derived from calcareous rocks. It often grows in association with other limestone-tolerant species in these summer-dry, erosion-prone habitats.
Plant Conservation
Classified as 'At Risk - Naturally Uncommon' due to its range being restricted to specific limestone habitats in Marlborough. While not immediately threatened with extinction, its small total population size and specific habitat requirements make it vulnerable. Primary threats include browsing by introduced mammals (goats, rabbits, hares) and encroachment by invasive weeds such as sweet briar ( Rosa rubiginosa ) and wilding pines, which can outcompete it for light and space.
Growing Requirements
Soil
Free-draining, lean soils; add grit to heavy ground to improve drainage.
Light
Full sun for strong form and seed-heads.
Water
Low once established; water to settle after planting.
Planting Guide
Planting Steps
Space 40-60 cm apart; set on a shallow gravel mound, water to settle, and mulch with grit to keep crowns dry over winter; trim spent stems in late winter.
Ecological Role
Environmental Benefits
This grass plays a crucial role in stabilizing erosion-prone limestone slopes and contributing to the biodiversity of Marlborough's dryland ecosystems. Its tussock habit provides shelter for ground-dwelling invertebrates, including native beetles and spiders. As a native grass, it is a likely host plant for the larvae of endemic copper butterflies and various native moth species that rely on Anthosachne species for food.
Uses
Traditional and Modern Applications
Valued primarily for restoration projects within its natural range, particularly for stabilizing dry, calcareous soils where few other plants thrive. In horticulture, its upright habit and blue-green (glaucous) foliage make it an attractive subject for dryland gardens and rockeries, where it contrasts effectively with darker-leaved native shrubs. It is an excellent candidate for low-water xeriscaping designs.
Landscaping Uses
Garden Design Applications
Excellent for rock gardens, alpine collections, and naturalistic plantings. Best used in open, well-drained positions where its distinctive form can be appreciated. Combines well with other native alpine plants and provides year-round structure. Consider placement carefully due to sharp foliage - avoid high-traffic areas. Creates dramatic focal points in contemporary and native-themed garden designs.
Seasonal Care
Year-Round Maintenance
Spring management focuses on removing winter-damaged foliage and assessing drainage. Summer care emphasizes maintaining adequate moisture without waterlogging. Autumn preparation includes reducing irrigation and ensuring good air circulation. Winter protection may require covering in areas subject to excessive moisture. Year-round monitoring ensures early detection of problems and maintenance of optimal growing conditions.
Pruning
Pruning Techniques
Minimal pruning is required. Remove dead thatch or spent flower spikes in late autumn to maintain a tidy appearance and encourage fresh growth. In garden settings, clumps can be gently combed with a rake to remove loose dead leaves without damaging the living base. Avoid cutting back hard unless the plant has become very untidy, as recovery can be slow.
How to Grow Marlborough Wheatgrass
Cultivation Requirements
Anthosachne sacandros is classified as "At Risk - Naturally Uncommon" and is not commercially available. This endemic grass requires specialized growing conditions that mimic its natural limestone cliff and river terrace habitat. Propagation from fresh seed offers the best success rates, though division of established clumps is also possible with careful technique.
Seed Collection and Storage
Seeds should be collected when fully mature, typically from December to May following the flowering period of October to February. This coastal species produces viable seed that should be collected from wild populations (where permitted) or obtained through conservation groups. Store seeds in dry, cool conditions in paper bags to prevent fungal problems. Fresh seed germinates more readily than stored seed, so sow as soon as possible after collection.
Seed Propagation
Sow fresh seed in autumn or early spring using a specialized gritty, free-draining seed mix that replicates the rocky soils of its natural habitat. The seed mix should contain pumice, sand, and small amounts of organic matter. Sow seeds shallowly, barely covering them with the propagating mix. Maintain barely moist conditions - overwatering will cause seed rot. Germination typically occurs within 2-3 weeks under optimal conditions. Provide bright light but protect from intense summer heat.
Division and Transplanting
Mature clumps can be carefully divided in early spring or late autumn when the plant is not actively growing. This method should only be attempted with well-established plants at least 3-4 years old. Dig up the entire clump, being careful not to damage the deep root system. Gently separate sections ensuring each division has healthy roots and several growing points. Divisions should be replanted immediately to prevent root desiccation.
Growing Environment
This species requires excellent drainage and full sun conditions. Plant in rocky, gravelly soils or raised beds with sharp drainage. Anthosachne sacandros naturally grows on limestone substrates from sea level to 900 meters elevation, so it tolerates both coastal conditions and inland sites. Avoid heavy soils, excessive moisture, and humid microclimates. Once established, this grass is drought-tolerant and requires minimal maintenance, making it ideal for rock gardens and naturalistic plantings that replicate its cliff-face habitat.
Pests & Diseases
Generally robust and disease-free in its preferred habitat. In humid climates or poorly drained soils, it may be susceptible to rusts or powdery mildew. Ensure excellent air circulation and avoid overhead watering to minimize these risks. Root rot can occur in waterlogged conditions.
Cultural Significance
Traditional Uses and Values
The specific epithet 'sacandros' distinguishes this species as a distinct entity within the New Zealand wheatgrass complex. While it shares general features with other native wheatgrasses, its recognition as a distinct species highlights the unique biodiversity of the Marlborough region. It serves as an emblem of the specialized flora that has evolved on New Zealand's dry eastern limestone landscapes.
Bonus Tip
Erosion Control
With its fibrous root system, this grass is excellent for stabilizing dry, crumbly banks. It tolerates low fertility soils well, slowly building up organic matter and preparing the ground for other native species to establish.
