Oncidium and tolumnia question

[Yevven]

Dear Orchid Board!

I have two relatively newly potted (the onc. in August, the tolumnias in November) orchids and they are doing semi alright.

My question is with the Oncidium, are the leaves okay, or should I do anything to them? It's an older bulb with less roots (getting plump slower then the others) and the leaves are getting yellower every week. The leaf tips are soft, brownish, then after a while they are crunchy. The other bulbs are gettint ready to flower and shooting up new roots.

My other question is with the tolumnias, if I should do anything with the yellowing fan. It was potted with the others in November in a shallow terracotta pot. I am planning to put a moss over the top of the clay/bark/perlite mix. Should I not pot them together or is there anything I should be aware of? (Moving them in separately into baskets is impossible, I do not have enough time and space to water them correctly)


They are getting Kelpak every 4 weeks, placed in a 20 C room on a windowsill. It's quite dry, around 30-50% usually. They are watered with rainwater.

Thank you everybody!

[Roberta]

Culture for Oncidium vs. Tolumnia is quite different. Oncidiums want to stay damp, they should never dry out. So small bark is appropriate for them. Losing leaves on the oldest pseudobulbs (and seeing them shrivel) is normal - all the energy is going to the new growth. But they do need water.

Tolumnias, on the other hand, are dominant epiphytes. They need to dry out between waterings. They really do best mounted, or in baskets (with little media, needs to be very fast drying if you use it at all).

[Yevven]

Thank you very much!

It's my first onc. so every tip is good to know

I'll just continue experimenting with these tolumnias then