Angraecum with brown patches update.

[BrassavolaStars]

Hello all,

The spots on my Angraecum seem to have gotten worse. I just took it back to the greenhouse from outside just now and I’ll see if that helps at all. It was perfectly fine until I took it outside a few weeks ago.

It does look like sunburn but I’m a bit skeptical as I did keep it in a shady spot under an umbrella and tried to face it away from the sun.

What does orchidboard think is wrong?

[Roberta]

I can't say for sure that it is sunburn, but it still sure looks like it. Shifting sun can be insidious - you can have severe effects in a very short time. I have a story to illustrate, from my experience... I have a small greenhouse. Roof gives about 50% shade, so light is generally quite even, and mild. I have 4 vents, that open automatically based on temperature. The vents are covered in the same polycarbonate as the roof. I started noticing sunburn on the leaves of just a few plants, and couldn't figure out where it was coming from because I could not see any hot spots. Well, one very warm morning I just happened to be in there about 10 AM and saw a shaft of light come in through an east-facing open vent. Most of the time the vents were still closed when the sun was in that spot, but because of the heat, the vent was open and it came blasting in with no shading. For about 5 minutes. Then the sun got high enough to be above the vent and got shaded. But that 5 minutes was enough to toast leaves... and to catch it in the act I had to be there at just the right moment. (I added some very open shade cloth on the inside of the greenhouse covering the vent... solved the problem, still lets air in)

Your plants might have gotten a similar transient blast. It doesn't take long...

[AnonYMouse]

Sunburn. Notice the "bikini" lines from where the leaves grew away?

[estación seca]

When it was on the table under the umbrella, the sun hit it either early in the morning or late in the afternoon. Moving plants outside for the summer is tricky. A plant like this could take 2-3 weeks to move out of a greenhouse to summering outdoors: A week under full shade, then a week under dappled light through a tree or under 70% shade cloth, then a week with 50% shade and some early morning light, and so on.

Midwestern cactus growers face the same issue. Their plants might tolerate full sun when adapted, but not after a winter indoors under lights.

[SouthPark]

Brassa - if you now have the plant in more shadier conditions -temporarily anyway - and if those patches dry up and become hard, and do not spread - then everything should be just fine. Don't worry too much about some scorching - as lots of orchids in the wild get a scorching.

Totally agree with E.S. and all - about taking some time and effort to sun-harden a plant, in order to prepare it for full sun, especially for powerful full sun conditions.