Repotting guide

When & how to repot Spider Orchid (Brassia verrucosa)

Also called Warty Spider Orchid.

More about spider orchid

About Spider Orchid

Brassia verrucosa · also called Warty Spider Orchid · flowering

Brassia verrucosa is an epiphytic spider orchid prized for arching sprays of long-petaled, spidery green flowers marked with dark warts. A cool-to-intermediate grower from Central America, it thrives in bright indirect light, fast-draining bark, high humidity, and a winter rest. Its starry blooms are wasp-pollinator mimics and can carry a light fragrance.

Mature size: Around 30-45 cm tall with arching spikes to 40 cm; spreads steadily across its mount or pot as new pseudobulbs form along the rhizome.

Watch for — Black, mushy roots or bulbs: Root rot from a soggy, broken-down mix or overwatering. Use fast-draining bark, water only when it dries, and repot if the medium has gone to compost.

How to tell spider orchid needs repotting

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

The bark medium has broken down into a dark, soggy, soil-like mush that no longer drains.
Roots are climbing out of the pot in all directions (this is normal for spider orchid and not on its own a reason to repot).
Roots inside the pot are brown, soft and rotting rather than firm and green/silver.
It is about two years since the last repot, or you can smell sour, decomposing bark — repot just after flowering finishes.

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 spider orchid

Every 1–2 years, when the bark breaks down. Spider Orchid's growth habit — sympodial epiphyte: a creeping rhizome produces clustered, flattened oval pseudobulbs, each topped by one or two strap leaves. arching flower spikes emerge from the base of mature bulbs, carrying a row of spidery blooms. — sets the pace. Brassia verrucosa is an epiphytic spider orchid prized for arching sprays of long-petaled, spidery green flowers marked with dark warts. A cool-to-intermediate grower from Central America, it thrives in bright indirect light, fast-draining bark, high humidity, and a winter rest. Its starry blooms are wasp-pollinator mimics and can carry a light fragrance.

What size pot to step spider orchid up to

Keep spider orchid in the same size pot, or go up just one, only if the roots have genuinely outgrown it. Orchids flower better slightly snug, and a big pot of bark stays wet and rots the roots. The reason you are repotting is the broken-down bark, not a need for more space — a clear pot lets you watch the roots.

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 spider orchid

Repot spider orchid immediately after the flowers have finished, just as new roots or a new growth start to emerge — those fresh roots establish quickly in new bark. Never repot an orchid in full bloom; you will drop the flowers and shock the plant.

Step-by-step: repotting spider orchid

Repot after flowering. Wait until spider orchid has finished blooming and is pushing new roots. Soak the pot first so the roots are pliable and less likely to snap.
Remove all the old bark. Slide the plant out and crumble away every scrap of broken-down bark — that soggy mush is the actual problem you are fixing.
Trim dead roots. Cut off any brown, hollow or mushy roots with sterilised snips. Keep all the firm green/silver ones.
Repot into fresh bark. Settle spider orchid into the same or one-size-up pot of fresh coarse open epiphytic bark mix, working bark between the roots so there are no big air gaps.
Hold off watering briefly. Mist or wait a few days before the first proper water so any cut roots seal. Then resume the normal soak-and-drain rhythm.

Aftercare

Give spider orchid a few days before its first proper watering so cut roots seal, then return to the weekly soak-and-drain. Keep it bright, humid and out of direct sun while new roots grip the fresh bark. It may pause growth briefly; that is expected. Do not fertilise for about 3 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for spider orchid

Spider Orchid wants open epiphytic bark mix. Medium-grade fir bark with perlite and a little charcoal or sphagnum, in a pot or basket that drains instantly. Roots must dry between waterings; a stale, water-retentive mix causes rot. Repot every 2 years as bark breaks down, right after flowering. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting spider orchid — frequently asked questions

How often should you repot spider orchid?

Every 1–2 years, when the bark breaks down for spider orchid. Repot spider orchid every 1–2 years — but because the bark medium has broken down and gone soggy, not because it has outgrown the pot. Do it just after flowering, into the same size or one up, using fresh open epiphytic bark mix. Old, decomposed bark suffocating the roots is the real problem.

What size pot does spider orchid need?

When is the best time of year to repot spider orchid?

Why does spider orchid get repotted if it isn't outgrowing the pot?

Because the bark medium breaks down. Over 1–2 years the chunky bark rots into a dense, soggy, soil-like mush that suffocates the roots — that, not size, is why you repot spider orchid. Refresh it into fresh coarse bark just after flowering.

Should you fertilise spider orchid after repotting?

Not immediately. Wait about 3 weeks after repotting spider orchid. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.