Tussock Grasses (Poa)

How to choose a tussock grass

Choose by height and colour. The common tussock grass (Poa labillardieri) is the largest, a dense green-grey clump about 1m tall and 90cm wide with plumes held above the leaves in summer; it is the grass of south-eastern grasslands and creek flats and the one to use for scale. Coastal tussock grass (Poa poiformis) is a little shorter at 70cm, blue-green and salt tolerant, the natural choice near the sea. The Poa sieberiana forms are finer and smaller: grey tussock grass and its blue variety sit around 60cm with narrow silver-grey or blue leaves, and the dwarf grey stays about 35cm, neat enough for a border edge or a pot. Rustic is a compact selection to 60cm with a bronze tint.

Where tussock grasses work

Full sun to light shade in almost any soil, from heavy clay to sand. Poas are at home in native and bush gardens, meadow and prairie-style plantings, mass plantings along driveways and on slopes that need holding, the edges of dams and swales, and verges. They grow in every capital city, take frost and drought once established, and the coastal tussock takes salt wind. In Brisbane and the subtropics they prefer a little afternoon shade and good drainage. Plant them in drifts of one kind rather than mixing colours, and pair them with kangaroo paws, lomandras and the other plants in our grasses for landscaping and Australian natives ranges.

Planting and spacing

Plant in autumn or spring. Space the common and coastal tussocks 70cm to 80cm apart for a continuous sweep, the grey and blue forms 50cm, and the dwarf grey 35cm to 40cm. Tubestock establishes quickly and is the economical way to plant a large area. Water weekly through the first summer; after that, rain is usually enough except in long droughts. Our guide to ornamental grasses in garden design covers how to lay out a planting.

Care basics

The one job is the annual cut. In late winter, before new growth, cut each clump back to about 10cm to 15cm and remove the old leaves; the clump refreshes within weeks and flowers better for it. In fire-prone areas this cut also removes the dry fuel a tussock holds, and the grasses are kept well away from the house. Feed lightly or not at all, since rich soil makes them floppy. Divide old clumps in autumn if the centre dies out. Poas self-seed a little in open soil; the seedlings are easily hoed or kept.

Common questions

How often should tussock grass be cut back?

Once a year in late winter, to about 10cm to 15cm. Skipping it leaves a thatch of dead leaves in the centre and the clump looks tired by midsummer.

Are poa tussock grasses native?

Yes. Poa labillardieri, Poa poiformis and Poa sieberiana all grow naturally across south-eastern Australia, and they are among the most useful grasses for habitat planting.

Do tussock grasses need much water?

Only while they establish. After the first summer they survive on rainfall in most of Australia and stay greener with an occasional deep soak in drought.

Which tussock grass suits a pot?

The dwarf grey tussock and the blue Poa sieberiana, both under 60cm. Use a premium mix and water more often than you would in the ground.