Renanthera monachica

[Nazz]

I’m not sure how to link my previous post, but:
The first photo is the plant right after I got it, shipped from SoCal to Baltimore. The second photo is what the plant looks like now after a little over a week. I have no idea what’s going on but the dark green and dark purple is now shades of fire engine red and yellow. It’s obviously getting worse. Is there any hope? It looks so sad.
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[TomThumb]

I'm no expert but from what i know from my vandaceous seedlings, the purple happens when they get to the max limit of sunlight exposure. It's ok to have a little but if you have a lot of purple I would suggest less light. Some of my seedlings got very purple but turned green again after a week of less intense light exposure. Too much light will hurt/kill your plant.

The yellow happens when the leaves die. And the red is the purple pigment on the yellow. This happened with two of my phals when they got way more light than they needed. My phals decided to drop their older leaves due to the stress of too much light. The leaves turned yellow and seemed to dry out as the plant retrieved resources and nutrients from it. However the purple pigment anthocyanin continued to be produced and overlaid the yellow dying leaf making it look red. So you basically fried your plant and it's upset.

I'm new to orchids but i got some seedling vandas like an idiot as my first orchids and i worked super hard to keep them alive. I did run into some issues but right now they are all doing well and pumping out juicy new roots. What i've noticed is that even though they are labeled as high light orchids, various vandas have different levels of affinity to light. Some actually seem to prefer a more...moderate light level which is more than what phals like but less than what true light loving vanda types like. For example I started with five different vandaceous seedlings. One of them turned purple right away even though it was given the same amount of light. I moved her away from the light and she was fine. Three others also started blushing purple. One quite badly. However one of the seedlings absolutely loves bright light and never even got a blush. It's the healthiest of the bunch since i was giving it what it wanted. The others had small setbacks mostly due to overexposure to light and in ability to quickly adapt to a new environment. But with careful observation you'll be able to tell what your orchid likes or doesn't like.

[Optimist]

Are the leaves mushy? Does it look like rotting? Did it freeze overnight? Did it have a heat pack when it went to Baltimore? Could it have frozen while it was in the mail? That looks really strange. The top one looked healthy with a bit of anthocyanins (the purple pigment). The yellow-brown colors look like dead or dying leaves.

[aliceinwl]

I got a seedling from the Santa Barbara Orchid Estate this past spring. They told me that these liked bright light but not direct sun and want to be watered daily but need to dry by nightfall. I’ve been keeping mine in bright shade with an hour or so of morning light; mine is purple too. I think this one is listed as an intermediate grower on its tag so it’s not too cold tolerant.

[stonedragonfarms]

To me this looks like it's possibly been kept too dry; as it's mounted and an intermediate/warm grower, it's going to need both good light and ample humidity. When conditions are incorrect, vandaceous genera plants will typically shed the bottom leaves to help prevent desiccation and minimize water loss; if conditions are not corrected, they will continue to shed leaves up the stem of the plant.
I don't grow this species, but I do have at least one plant using it as a parent; mine get watered 2x a week, and misted 2x daily, even on watering days. I'd try upping both the rh in your grow area and the frequency of its watering; as the mount is relatively small, you might try a modification on the "vase" method for vanda culture, to localize humidity around the plant.
Good luck
AP

[King_of_orchid_growing:)]

The original post in this thread was started a couple of months ago. But if people are curious about how to grow this plant, then maybe these tips can help...

Renanthera monachica is not the easiest of all the Renantheras to grow, but it is still possible to grow them. Consider them moderately easy to grow.

This orchid grows well in a temperature range of 60 F - 85 F. It is not all that tolerant of temperatures in the temperature range of 50 F - 59 F. If the temperature drops to about 55 F - 57 F, this species is more apt to start dropping leaves, (rather quickly might I add).

The light should be indirect moderately bright to indirect bright light.

More importantly, do not overwater this orchid, it is a bit touchy in this regard. This species likes to dry out completely before needing to be watered again. It doesn't like its roots to stay wet for more than 1 day. The roots like a decent amount of air.

I recommend growing in a wood slat basket without moss.

[aliceinwl]

Is the purple color good on these? My seedling was pretty purple when it was out on the fence. I’ve moved it over with my Phalaenopsis so that I can bring it in at night now that it’s getting colder and it’s gotten much greener. Which foliage color should be the target?

[TomThumb]

seedlings are more sensitive to light and need to be slowly adjusted to high light even if the parents are high light plants. A small touch of purple is ok but don't let your entire plant turn purple. I came across this same issue when i got my vanda seedlings. I moved them toward more shade and a few months later they're sitting in stronger light. with just a slight tinge of purple/red on two of them and the other five are all green.

[aliceinwl]

Thanks for the info! I’ll keep it more shaded when it goes back out to the fence in spring.

[King_of_orchid_growing:)]

Originally Posted by aliceinwl

Is the purple color good on these? My seedling was pretty purple when it was out on the fence. I’ve moved it over with my Phalaenopsis so that I can bring it in at night now that it’s getting colder and it’s gotten much greener. Which foliage color should be the target?

I rarely see anthocyanin pigmentation on the top portion of the leaves of Renanthera in general. Anthocyanin pigmentation that I have seen have usually been restricted to either the edges of the leaves or to the underside of the leaf. It's not to say that it can't happen, it's just that I rarely see it.

The leaves on Renanthera monachica tend to naturally be pretty dark green so it can be a bit tricky to figure out whether it is getting enough light or not.

Without seeing a photo of your plant, it's hard to say definitely that your plant is going to be ok or not, but I will say that judging off of what you had said, as you've already been recommended, I'd reduce the intensity of light your plant is getting.

At the moment, I'm aware of only 2 species of Renanthera that naturally have light green leaves instead of dark green leaves, and they are: Renanthera citrina and Renanthera imschootiana. These are the 2 species of Renanthera I usually like to recommend to those who are starting off growing this genus of orchid. Both are relatively compact, (along with Renanthera monachica), compared to the other species, and they tend to be a bit easier to grow. It is also a bit easier to tell if they are getting enough light or not enough for these 2 species.