I found a black spot on my Angraecum 'Mark Aldridge.'

[Butters]

Hi, guys. I found a black spot on the crown of my Angraecum 'Mark Aldridge.' There is also some yellowing around the black spot. Is this crown rot or the start of it?

[estación seca]

It does look like a fungal infection. Are there any good garden centers near you? I would take the plant to an experienced nurseryman and ask which fungicide to use.

In the mean time, pour some 3% hydrogen peroxide into that part of the plant. Try to work it between the leaves. It would be very hard to remove this leaf without further damaging the plant and opening another spot for fungus to enter.

[Leafmite]

Angraecums seem to be more prone to fungus issues than many other orchids. Most people use a preventative fungicide. I have had luck by giving mine more Calcium and trying to make certain that water doesn't sit on the leaves for too long.

I would recommend a systemic fungicide or, if that cannot be found, Captan (with copper). Captan is pretty powerful and must be used with caution.

[Butters]

I don't really understand how this happened. I water it with a watering can, making sure only to water the root area.

Estacion, should I dilute the 3 percent hydrogen peroxide? How often should I use it?

Would liquid copper work? At Home Depot we sell a fungicidal product called Daconil. Would that work?

[estación seca]

Don't dilute the 3% hydrogen peroxide. Copper can be toxic for some orchids, so I wouldn't use that without advice from an experienced orchid grower in Florida. I'm not familiar with fungi of Florida nor fungicides. I know they can vary in different parts of the country. That's why I would ask somebody there who knows.

Give a call to one of the orchid vendors in Homestead.

[Leafmite]

Here is a great place to look for information on Angraecums. I believe this grower is also in Florida. He says that he uses a systemic fungicide every 30 days (Thiomyl).

I have never used a fungicide on the orchids so I cannot say whether the copper would harm the Angraecum or not. I would go with the Thiomyl.

Good luck!