Rananthera philippinensis with yellow leaves

[LoveOrchids2]

Hi I am new in this forum and I am looking forward to learn and share with you. I am writing because about two months ago (Feb 20 2021) I bought a vanda Rananthera philippinensis and now the leaves are turning yellow. I have been spraying with neem oil which seemed to work at the beginning, however, I am getting yellow leaves everywhere on the plant. I have attach a picture. Any advice?

[Roberta]

First, Welcome!

Where are you located? Can you tell us more about the conditions under which you are growing this plant? The first thing that I think of is that it's not getting enough water. Losing leaves is one of the responses of members of the Vanda group - since leaves lose water by transpiration, it it senses a "drought" it responds by trying to lose less water - dropping leaves. A bare-root plant like this needs to be watered daily - watered long enough so that the roots turn green. High humidity helps... If you are someplace other than south Florida, there are other things that you can do. A number of members of the Board successfully grow Vandaceous orchids under less-than-tropical conditions, I am sure that some will jump in with ideas.

[LoveOrchids2]

Hi Roberta,
Thank you very much for your prompt response. I live in Puerto Rico. I have the plant inside my house in front of a window where I have a small interior garden (see attached picture). I water the plant daily, using rain water that I collect, by placing it inside a bucket for at least 15 minutes. I was thinking that it might need more light, however, I have other vandas on the same area which are doing well.

[Roberta]

Neem oil is specifically useful for insects, mites, etc... bugs... so if you have a problem with pests, it can be useful. But if it is some other issue, won't help and might even clog pores of leaves. So it is important to figure out what you're treating. How about fertilizer? Although if you're treating it like your other Vandas, it is probably getting what it needs. It could just be the stress of a new environment. Certainly, your climate should be fine. (Is there a place where it can be outside? Rain and fresh breezes that it could get naturally might be beneficial)

[estación seca]

Welcome to the Orchid Board!

I might suspect not enough light and not enough fertilizer. The leaves are very dark green. Not all Renantheras need full sun, but they prefer more light than many other orchids.

[LoveOrchids2]

Thanks both for your advice. I will be trying them