grass

Grey Tussock-Grass

Poa sieberiana

The Story

Plant Bio

Poa sieberiana is a densely tufted, fine-leaved perennial grass that forms a neat, rounded mound of upright to arching foliage. Native to Australia, it produces delicate, open panicles of pale green to purplish flowers on slender stems that rise above the silvery-blue or grey-green leaves.

This species is highly valued for its exceptional frost tolerance and ability to withstand prolonged dry spells once established. Its fine-textured, narrow foliage remains structurally sound throughout the growing season, providing excellent contrast in mixed borders or rock gardens.

Uses & Benefits:

Provides a fine-textured, silvery-blue to grey-green focal point with delicate, airy flower panicles.

Excellent for stabilizing slopes and controlling soil erosion on dry banks due to its fibrous root system.

Offers nesting material and protective cover for small birds and beneficial insects.

Essentials

At a Glance

Plant Type

Grass

Height

24"

Width

20"

Light

Full Sun, Partial Sun

Zones

7, 8, 9, 10

Water

Low

Humidity

Moderate

Lifespan

Perennial

Native To

Australia

Toxicity

Non-toxic

Bloom period

Spring – Summer

In flower about 6 months of the year

Planting

How to Grow

Select a planting site with full sun to partial shade and exceptionally well-drained soil.
Dig a hole twice the width of the root ball and set the plant so the crown sits level with the surrounding soil.
Water deeply immediately after planting to settle the soil around the roots.
Apply a thin layer of organic mulch around the base, keeping it clear of the foliage crown to prevent rot.

Pro Tip

Avoid shearing this grass annually; instead, cut the clump back to two to four inches above the ground only every three to four years in late winter to clear out dead thatch without killing the crown.

Keep It Thriving

Care Guide

Do

Provide sharp soil drainage to prevent root rot during wet winter months.
Prune back hard to two to four inches every three to four years in late winter to rejuvenate the clump.
Water sparingly once established, allowing the soil to dry out between waterings.

Don't

Do not shear the foliage annually, as frequent severe cutting into old wood can kill the plant.
Do not apply heavy fertilizers, which cause weak, floppy growth and reduce structural integrity.
Do not plant in low-lying areas prone to standing water or prolonged waterlogging.

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Divide
Pest Check
Plant
Prune
Spring Cleanup

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Rock GardenMass PlantingErosion ControlBorder EdgingWild & Naturalistic

Companion Plants

Muhlenbergia capillaris Festuca idahoensis Salvia apiana Achillea millefolium

Multiply

Propagation Methods

Good to Know

Common Questions

Grey Tussock-Grass questions

What zones can Grey Tussock-Grass grow in?

Grey Tussock-Grass is hardy in USDA Zones 7–10. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

Is Grey Tussock-Grass deer resistant?

Not reliably. Deer may browse Grey Tussock-Grass, especially tender spring growth — plan on repellents or fencing where pressure is high.

When does Grey Tussock-Grass bloom?

Grey Tussock-Grass typically blooms in spring through summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Grey Tussock-Grass need full sun?

Grey Tussock-Grass does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.

Is Grey Tussock-Grass drought tolerant?

Yes — once established (usually after the first full season), Grey Tussock-Grass handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.