Repotting guide

When & how to repot Pheasant Tail Grass (Anemanthele lessoniana)

Also called pheasant tail grass, wind grass, gossamer grass.

More about pheasant tail grass

About Pheasant Tail Grass

Anemanthele lessoniana · also called pheasant tail grass, wind grass · flowering

Pheasant tail grass (Anemanthele lessoniana), a New Zealand native once classed as Stipa, is an evergreen clumping grass famed for foliage that shifts from green to fiery orange, bronze and copper as the seasons cool. In summer it throws a haze of fine, airy purplish flower panicles that catch the breeze. Drought-tolerant and graceful, it suits sunny borders, gravel gardens and containers.

Mature size: Foliage mound about 60-90 cm tall and wide; airy flower panicles arch to roughly 1-1.2 m.

How to tell pheasant tail grass needs repotting

Repotting on a calendar is less reliable than reading the plant. For pheasant tail grass, watch for these signs:

Roots spiralling thickly out of the drainage holes or pushing the whole plant up out of the pot.
The pot is so packed that water runs straight through in seconds and barely wets the soil.
It has split a plastic pot, or the rootball is a solid mass with almost no soil left when you slide it out.
Growth and (for pheasant tail grass) flowering have clearly stalled despite good light and feeding — but remember this plant likes being snug, so a little crowding alone is not a reason to repot.

For the underlying biology of a pot-bound root system and why it stalls a plant, see our guide to spotting and fixing a root-bound plant.

How often to repot pheasant tail grass

Only every 2–4 years, when genuinely crowded. Pheasant Tail Grass is one of the plants that genuinely prefers a snug pot — it grows and flowers better with its roots a little restricted, so resist the urge to repot it on schedule. Evergreen, densely tufted clump-forming bunchgrass with fine arching blades that recolour through the seasons, overtopped in summer by a cloud of delicate, gossamer-like flowering panicles..

What size pot to step pheasant tail grass up to

Go up only one pot size — roughly 2–3 cm (about an inch) wider in diameter, no more. Pheasant Tail Grass positively prefers a snug pot: it flowers and grows better when the roots are a little restricted. The single biggest repotting mistake here is over-potting — dropping pheasant tail grass into a pot two or three sizes up. All that surplus soil holds water the small root system cannot use, stays cold and wet, and rots the roots within weeks. When in doubt, choose the smaller pot.

Not sure of the exact diameter? Our pot size calculator takes the current pot and root spread and tells you the right next size — it deliberately recommends a single step up, never a big jump.

The best time of year to repot pheasant tail grass

Early spring, just as new growth restarts, is the ideal window for pheasant tail grass. The plant is moving into its strongest growth phase and re-roots into fresh soil quickly. Avoid repotting in winter dormancy or, for flowering plants, while it is in bud or bloom — recovery is slowest then and you risk dropping the flowers.

Step-by-step: repotting pheasant tail grass

Confirm it actually needs it. Slide pheasant tail grass out and check the roots. Only continue if it is genuinely packed — this plant prefers a snug pot, so if there is still soil and room, put it straight back.
Pick a pot only one size up. Choose a pot just 2–3 cm wider with good drainage. Resist anything bigger; over-potting is the main killer here.
Ease it out gently. Water lightly the day before, then tip pheasant tail grass out, supporting the base. Tease the outer roots free only enough to stop them circling.
Repot at the same depth. Add a layer of fresh fertile, free-draining loam, neutral to slightly acidic or alkaline, set the plant so the soil line sits exactly where it did before, and backfill around the sides, firming lightly.
Settle it in. Water once to settle the soil, then let it sit. Hold off on more water until the top of the soil dries — fresh soil around a small root system stays wet for a while.

Aftercare

Because the new soil holds more water than the old crammed rootball did, ease right back on watering — let the top of the soil dry before you water pheasant tail grass again, or you will rot the roots in the very pot you just moved it to. Keep it out of harsh direct sun for a fortnight. Do not fertilise for about 4 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for pheasant tail grass

Pheasant Tail Grass wants fertile, free-draining loam, neutral to slightly acidic or alkaline. Adapts to most well-drained soils, including sandy and gravelly types, and tolerates a range of pH. It dislikes heavy, wet clay; improve drainage with grit. Moderately fertile, sharply drained soil gives the best growth and colour. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting pheasant tail grass — frequently asked questions

How often should you repot pheasant tail grass?

Only every 2–4 years, when genuinely crowded for pheasant tail grass. Only repot pheasant tail grass every 2–4 years, and only when it is genuinely root-bound — it flowers and grows best slightly crowded. Step up just one pot size in spring using fertile, free-draining loam, neutral to slightly acidic or alkaline. The key mistake is over-potting: a too-big pot stays wet and rots the roots.

What size pot does pheasant tail grass need?

When is the best time of year to repot pheasant tail grass?

Does pheasant tail grass like to be root-bound?

Yes — pheasant tail grass genuinely flowers and grows best when slightly pot-bound, so do not rush to repot it. The mistake to avoid is over-potting into a much larger pot: the excess soil stays wet, the roots cannot use it, and the plant rots. Only repot every few years and only one snug size up.

Should you fertilise pheasant tail grass after repotting?

Not immediately. Wait about 4 weeks after repotting pheasant tail grass. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.