Oncidium Bud Blast: Wilting Flowers, Unopened Buds, and Care Corrections

Question:

I think I have Oncidium sphacelatum (white flowers with rust/yellow). Bought a month ago from nursery, in bloom. Near window with indirect light. Not repotted. Now flowers wilting, dry to touch; no buds on long spike have opened. Cut spike? Water weekly. Charlotte, NC—warm days, cool nights. 8–10 long leaves, look okay but sometimes feel dry.

Answer:

Hello Garima,

True Oncidium sphacelatum flowers are mostly yellow—yours may be different. Buds sound "blasted" (died). Common causes: sudden temp changes >15°F, nearby fruit, fresh paint fumes. Since buds won't open, cut the spike.

In Charlotte, you can give several hours of direct early morning sun. Ideal: 55–85°F, humidity >40%, light air movement. Keep moist (not wet) spring–mid-fall; slightly dry winter. Fertilize lightly (~¼ label rate) during active growth.

Jim Kawasaki
San Jose, CA