Repotting guide

When & how to repot Arching Spider Orchid (Brassia arcuigera)

Also called Spider Orchid, Arching Brassia.

More about arching spider orchid

About Arching Spider Orchid

Brassia arcuigera · also called Spider Orchid, Arching Brassia · tropical

Brassia arcuigera is a spectacular Colombian and Ecuadorian epiphyte producing long, arching spikes of spider-like flowers with extraordinarily elongated greenish-yellow petals and sepals spotted with brown. It blooms in spring to summer and is a popular parent of Brassidium hybrids. Orchidaceae; non-toxic to pets.

Mature size: 30-50 cm tall; arching flower spikes 40-70 cm bearing 6-12 large blooms

Watch for — Root rot: A common result of overwatering or a decomposed bark mix. Inspect roots at repotting; brown, mushy roots should be trimmed cleanly and dusted with cinnamon or fungicide.

How to tell arching spider orchid needs repotting

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

Roots poking out of the drainage holes or coiling visibly around the inside of the pot.
You are watering far more often than you used to because the rootball dries out within a day or two.
Water runs straight through and out the bottom without soaking in.
Top growth has slowed or new arching spider orchid leaves are noticeably smaller than older ones despite good light.

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 arching spider orchid

Every 12–18 months — sooner if roots show fast. Arching Spider Orchid's growth habit — sympodial epiphyte with large, egg-shaped compressed pseudobulbs — sets the pace. Brassia arcuigera is a spectacular Colombian and Ecuadorian epiphyte producing long, arching spikes of spider-like flowers with extraordinarily elongated greenish-yellow petals and sepals spotted with brown. It blooms in spring to summer and is a popular parent of Brassidium hybrids. Orchidaceae; non-toxic to pets.

What size pot to step arching spider orchid up to

Step up one pot size — about 2–3 cm (an inch) wider. Arching Spider Orchid grows fast, so it will fill that space within a season, but jumping several sizes at once still backfires: the unused soil stays soggy and rots even a vigorous root system. One size at a time, every year or so, is the rhythm.

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 arching spider orchid

Early spring, just as new growth restarts, is the ideal window for arching spider orchid. 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 arching spider orchid

Time it for spring. Repot arching spider orchid in early spring as growth restarts so it re-roots quickly into the fresh soil.
Choose one size up. Pick a pot about 2–3 cm wider with drainage holes. One step only — a much bigger pot stays soggy and rots roots.
Ease the plant out. Water lightly the day before, then tip arching spider orchid out and gently loosen any roots circling the bottom of the rootball.
Repot at the same depth. Put a layer of fresh medium orchid bark with perlite in the new pot, set the plant so its soil line is unchanged, and backfill, firming lightly.
Water and pause feeding. Water once to settle the soil. Hold off fertiliser for about a month — fresh mix already has nutrients and feeding now burns new roots.

Aftercare

Water arching spider orchid once to settle the soil, then let the surface dry before watering again — fresh mix around the roots stays wetter than the old compacted ball, so the commonest post-repot mistake is overwatering. Keep it out of direct sun for a week or two while roots re-establish. Do not fertilise for about 4 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for arching spider orchid

Arching Spider Orchid wants medium orchid bark with perlite. A well-drained medium bark mix with 20-25% perlite replicates the fast-drying epiphytic conditions this species is adapted to. Avoid mixes that stay wet for more than 3-4 days. Repot every 2 years. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting arching spider orchid — frequently asked questions

How often should you repot arching spider orchid?

Every 12–18 months — sooner if roots show fast for arching spider orchid. Repot arching spider orchid roughly every 12–18 months, in early spring as growth restarts. It grows fast and circles its pot quickly, so step up one size (about 2–3 cm wider) into fresh medium orchid bark with perlite. Don't jump several sizes — that soggy excess soil is what rots vigorous roots.

What size pot does arching spider orchid need?

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

Can you put arching spider orchid straight into a much bigger pot?

No. Even a fast-growing arching spider orchid should only go up one pot size at a time. A vastly oversized pot holds a reservoir of wet soil the roots cannot reach, which stays cold and soggy and rots the roots — the opposite of what you wanted.

Should you fertilise arching spider orchid after repotting?

Not immediately. Wait about 4 weeks after repotting arching 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.