Repotting guide

When & how to repot Cabbage Fern (Aglaomorpha coronans)

Also called Crown Basket Fern, Basket Fern, Crowning Polypody.

More about cabbage fern

About Cabbage Fern

Aglaomorpha coronans · also called Crown Basket Fern, Basket Fern · tropical

Aglaomorpha coronans is a large epiphytic fern from tropical Asia, prized for its dramatic, deeply lobed fronds that fan out like a crown. It thrives in bright indirect light with consistently moist, well-draining growing medium and high humidity. Not listed as toxic by the ASPCA — considered pet-safe like most true ferns.

Mature size: 60-100 cm tall with fronds spanning up to 120 cm in optimal conditions

Watch for — Root rot: Results from dense, waterlogged media. Repot into a chunkier epiphyte mix and reduce watering frequency.

How to tell cabbage fern needs repotting

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

Roots creeping out of the drainage holes or matting tightly across the soil surface.
The rootball dries out within a day or two no matter how much you water.
Water channels straight down the gap between rootball and pot without wetting the centre.
Steady decline — thin growth, persistent crispy edges — that good humidity and watering have not fixed. Only then is the disturbance of a repot worth the risk for cabbage fern.

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 cabbage fern

Every 1–2 years, disturbing the roots as little as possible. Cabbage Fern's growth habit — large epiphytic rhizomatous fern with arching, deeply pinnate fronds — sets the pace. Aglaomorpha coronans is a large epiphytic fern from tropical Asia, prized for its dramatic, deeply lobed fronds that fan out like a crown. It thrives in bright indirect light with consistently moist, well-draining growing medium and high humidity. Not listed as toxic by the ASPCA — considered pet-safe like most true ferns.

What size pot to step cabbage fern up to

Go up only one size and handle the rootball as little as possible. Cabbage Fern resents root disturbance, so the goal is to slide the intact rootball into slightly more soil — not to tease, wash or prune the roots. A modest step up means less shock and a faster recovery.

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 cabbage fern

Early spring, just as new growth restarts, is the ideal window for cabbage fern. 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 cabbage fern

Keep disturbance to a minimum. Cabbage Fern resents root disturbance, so the plan is to move the intact rootball — not to wash, tease or prune the roots.
Choose just one size up. Pick a pot only one size larger with drainage, and have moisture-retentive chunky, free-draining epiphyte mix ready.
Slide the rootball out whole. Water the day before, then ease cabbage fern out keeping the rootball intact. Gently free only the roots that are circling the very bottom.
Nestle it into fresh soil. Add a base layer of fresh mix, set the rootball in at the same depth, and backfill gently around the sides without packing hard.
Water and protect. Water in, then keep it warm, humid and out of direct sun for a few weeks while it re-roots. Expect a short sulk — that is normal.

Aftercare

Expect cabbage fern to sulk for a couple of weeks — that is normal after any root disturbance for this group. Keep it warm, humid and out of direct sun, water just enough to keep the mix lightly moist, and do not panic and overwater while it re-roots. Do not fertilise for about 4 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for cabbage fern

Cabbage Fern wants chunky, free-draining epiphyte mix. Use a blend of orchid bark, perlite, and sphagnum moss (roughly 2:1:1). Can also be mounted on a wooden board or cork slab with sphagnum moss around the rhizome. Avoid dense peat-heavy mixes that stay too wet. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting cabbage fern — frequently asked questions

How often should you repot cabbage fern?

Every 1–2 years, disturbing the roots as little as possible for cabbage fern. Repot cabbage fern every 1–2 years, disturbing the roots as little as possible — it sulks for weeks if the rootball is teased apart. Slide it into one size up in spring with fresh chunky, free-draining epiphyte mix, keep it warm and humid afterwards, and never bare-root or hard-prune the roots.

What size pot does cabbage fern need?

When is the best time of year to repot cabbage fern?

Why does cabbage fern sulk after repotting?

Cabbage Fern resents root disturbance, so a wilt or stall for a week or two after repotting is normal, not a failure. Minimise it by keeping the rootball intact, stepping up just one size, and keeping the plant warm, humid and out of direct sun while it re-roots.

Should you fertilise cabbage fern after repotting?

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