Repotting guide

When & how to repot Trim Greenhood (Pterostylis concinna)

Also called Trim Greenhood Orchid, Neat Greenhood.

More about trim greenhood

About Trim Greenhood

Pterostylis concinna · also called Trim Greenhood Orchid, Neat Greenhood · tropical

Pterostylis concinna is a dainty Australian terrestrial orchid producing neatly proportioned, green and white hooded flowers, often in small clusters. It grows from tubers in coastal scrub and open woodland in southeastern Australia. Like all Pterostylis, it needs cool conditions, good drainage, a dry summer dormancy, and shade. Pet-safe as an orchid.

Mature size: 10-20 cm tall when in flower

Watch for — Over-potting: Growing in too large a pot causes the medium to stay too moist. Use the smallest pot that comfortably accommodates the tubers.

How to tell trim greenhood needs repotting

Repotting on a calendar is less reliable than reading the plant. For trim greenhood, watch for these signs:

Flowering has tailed off year on year and the clump has become congested and overcrowded.
Lots of leaf and few flowers — a classic sign that trim greenhood bulbs or tubers need lifting and dividing.
Bulbs visibly bursting the pot or pushing each other to the surface.
It is the natural dormancy window (foliage yellowed and died back) — the only safe time to lift and split.

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 trim greenhood

Lift and divide every 3–4 years once clumps congest. Rather than a true repot, trim greenhood is lifted and divided once the clump congests and flowering drops off. Small deciduous terrestrial orchid forming basal rosettes in the growing season; dormant tuber in summer.

What size pot to step trim greenhood up to

Pot size matters less than depth and spacing here. When you replant trim greenhood, set the bulbs or tubers at the correct depth (a rough guide: two to three times their own height of soil over the top) and space them so they are not touching. A wide, shallow pot suits a clump better than a tall narrow one.

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 trim greenhood

The only safe window is dormancy: wait until the foliage has yellowed and died back naturally, lift and divide then, and replant before or at the start of the next growing season. Disturbing trim greenhood in full growth or flower sets it back badly.

Step-by-step: repotting trim greenhood

Wait for dormancy. Let trim greenhood foliage yellow and die back completely. Lifting while it is in growth wastes the energy it is storing for next year.
Lift carefully. Loosen the soil well away from the bulbs/tubers with a fork and ease the whole clump out without spearing them.
Separate the offsets. Gently pull the clump apart into individual bulbs or tubers. Keep only firm, healthy, blemish-free ones.
Replant at the right depth. Reset them in fresh sandy, well-draining woodland mix at the correct depth and spacing — not touching — so each has room to bulk up.
Water in and rest. Water once to settle them, then keep on the dry side until growth resumes. Do not feed until leaves are actively growing.

Aftercare

After replanting trim greenhood, keep the soil barely moist — not wet — until shoots appear; bulbs and tubers rot in cold, saturated soil. Once leaves are growing strongly, resume normal watering. Hold off feeding until the plant is in active growth again.

The right soil mix for trim greenhood

Trim Greenhood wants sandy, well-draining woodland mix. A mix of coarse sand, perlite, and leaf mould or coco coir suits this species well. The mix should drain rapidly while holding a little moisture. Avoid rich, nutrient-loaded composts. Use shallow pots with multiple drainage holes. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting trim greenhood — frequently asked questions

How often should you repot trim greenhood?

Lift and divide every 3–4 years once clumps congest for trim greenhood. Trim Greenhood is lifted and divided, not "repotted". Every 3–4 years, once the foliage has died back and it is dormant, lift the clump, separate the offsets, and replant at the correct depth in sandy, well-draining woodland mix. Crowding, not pot size, is what reduces flowering over time.

What size pot does trim greenhood need?

When is the best time of year to repot trim greenhood?

Do you "repot" trim greenhood, or lift and divide it?

You lift and divide it. Trim Greenhood grows from bulbs or tubers, so instead of repotting you wait for dormancy, lift the congested clump, separate the healthy offsets, and replant them at the right depth and spacing. Doing this every 3–4 years restores flowering.

Should you fertilise trim greenhood after repotting?

Hold off feeding trim greenhood until it is in active growth again. Fresh soil already carries enough nutrients to get it re-established, and feeding disturbed roots too soon does more harm than good.