Ren. Philipenesis with yellowing leaves

[Routzah2]

Hi all,

I got a renanthera philipenesis back in mid november and am located in the east bay of Ca. I ended up potting it in a net basket sitting in a solid clear plastic basket with coarse bark to try and increase the humidity around the roots a bit. I had 3 leaves yellow from the bottom of the plant up and i took them off in december. I've recently had several more leaves yellow and did the same. I've heard this can come from the cold but given i keep them inside I'm pretty sure they never seen anything below 63 besides the occassional draft when i've open a window for a short bit.

I've seen several aerial roots also start but seem to have gone mostly dormant at the moment. There's also a seperate attached stalk in front that seems to be perfectly ok as well.

I typically water twice a week and mist throughout. It's in a northeast window and i'm giving supplemental light with LED grow light. This seems to be okay for another vanda ( roberts delight something) i have and a b. Little stars.

Any thoughts on if this is a problem with culture or what could be causing this? Or am i simply dotting on nothing?

Pictures are of yellowing leaf, plant as of the moment, and the plant when I got it.

Thanks!

[Roberta]

Temperature sounds OK, I suspect that it would really like more humidity than it is likely to get in the house. Perhaps soak it in a bucket every few days. If the roots are REALLY hydrated(nice and green), it will put up with low humidity better.

[King_of_orchid_growing:)]

You've probably figured it out by now.

What you're seeing is normal. Lower leaves will automatically die from old age. But if the yellowing is rapidly progressing up the plant to the top leaves, that is a sign of severe stress.

If it is the latter, you have to figure out what the stressor is quickly or you may not catch it in time.

Unfortunately, different stressors will produce this effect. Only you'd know what you did or didn't do to the plant.

A low end temperature of 63 F at night is fine. Anything lower, and you may experience problems for this particular species.

Not enough light will also produce this kind of behavior. Make sure your lighting is on point.

Severe dehydration will cause rapid yellowing of leaves as well.

But like I said, if the yellowing is very slow and is limited to the lower leaves only and not rapidly progressing up the plant, you're ok.

I'm also going to throw in a nitpick about naming conventions. I do this to not confuse myself or others, and I will explain why in a moment...

Names of a species plant have the genus portion of their names start with a capital letter. The species portion of their names start with a lower case letter.

Names of an unnatural hybrid, (man-made hybrids), have the genus portion of their names capitalized as well as their cultivar names.

Names of natural hybrids are written like species orchids, except there is a 'x' in front of the species name.

Why should anyone care?

This is why...

At one point in time, some people decided to be clever and name their hybrids so similarly to what a species name would look like, people who wanted to collect species orchids only, would get confused by the name of the hybrid. This is but one reason why it matters.

Sticking to naming conventions also makes finding care advice a little easier. Instead of looking things up in a database of species orchids, they may look things up in a database of hybrids instead.

If the hybrid's name is obviously not deliberately made to resemble a species name, everything is relatively easy. Unfortunately, that is not the case.

Like I said, naming conventions don't make things muddy.

I also believe, (if I'm not mistaken), that the practice of naming hybrids to resemble species names may no longer be in use, (at least, I hope it's not in practice).

With your plant, it would be: Renanthera philippinensis.

[estación seca]

This is a hot and wet tropics plant.

Renantheras normally keep all their leaves for many years, and a happy plant will have leaves down to its base. Yellowing lower leaves on a smaller plant indicate something is wrong. They need some full direct sun every day. Florida Renanthera growers told me they won't flower without 4-6 hours of direct Florida sun.

They need plentiful watering more than high humidity. Your temperatures aren't low enough to kill it, but are too low for it to he happy, and you shouldn't expect much growth until it's much warmer.

I would suppose you aren't watering enough and you aren't providing enough light.

[King_of_orchid_growing:)]

The lower leaves will last a long time, (several years), but they do not last forever either.

If there is something wrong, I don't think it is temperature related in this case. If something was off, it is either light or water.

California also tends to be quite dry the further inland you go and the further south you are in the state.

As an aside note, when watering make sure the roots dry out completely between watering.

[fishmom]

Hello Routzah2! Welcome to the board. You don't say where in the East Bay you are located, but just in case this is convenient for you, I am including a link to the Diablo View Orchid Society, which meets in Concord on the second Thursday of each month. We are a friendly bunch, and there is lots of opportunity to ask questions, see other members' plants, hear speakers, and generally have a good time. Hope to see you there!
Diablo View Orchid Society