Water thoroughly when the potting medium is nearly dry, typically once a week. Avoid letting the roots sit in waterlogged conditions, as this can lead to root rot.

Reduce watering slightly during cooler periods when growth slows.

Remove spent flower spikes at the base once blooming has finished. Cut away any dead, damaged, or dried pseudobulbs or leaves. Pruning promotes air circulation and directs energy towards new growth.

Orchids like Oncidium altissimum are best propagated by division.

When the plant becomes crowded and has multiple pseudobulbs, carefully divide it into sections, ensuring each section has at least 2-3 healthy pseudobulbs and some roots. Replant immediately.

Repot every 2-3 years or when the potting medium breaks down. Use a well-draining orchid mix, such as bark chips and perlite. Repot after flowering, before new root growth begins, to minimize transplant shock.