Phaius - Black spotting/leaves turning black - Orchid Board

Kokothefirst · #1 09-18-2013, 08:25 PM

Tips of my phaius turned black early on. Stopped fertilizing, and this stopped. at the same time, small black spots appeared towards the base of the leaves, but did not seem to spread, so I attributed to fertilizing also. Now I have a different appearing black spotting happening, and one of the smaller leaves is rotted almost entirely. Help! Any idea? Obviously a fungicide could be in order, but not certain which one, as not many have these plants, and I cant find like symptoms anywhere.

Thanks!

Kokothefirst · #2 09-19-2013, 09:27 AM

Anyone?

Paul Mc · #3 09-19-2013, 09:40 AM

I have three varieties of these plants and also get this. Given the fact that some orchids display spotting naturally, I assumed that it might be natural to Phaius species and hybrids as well. I have never sprayed as a result, but if you do believe it to be something you need to address then try Physan 20. Just make sure you only mix enough of it for the one time application as it doesn't have a long shelf life once mixed from what I understand.

You mentioned one rotted though which leads me to assume that you might have had a heavy watering hand with it. One of mine started to rot earlier this year when new growth began to appear. I held back on the amount of water I gave it and it recovered after a few weeks.

On a side note, is it possible that the part that died was just old and was time for it to go? Was the pseudo bulb mushy or was it still hard and green? I ask because they are semi-deciduous by nature and its natural for it to shed older leaves on nearly a yearly basis.

Paul McMahon
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Kokothefirst · #4 09-19-2013, 11:58 AM

Hi Paul, thanks for replying. I don't believe this was a case of it just being time for the leaf to go. The pseudo bulb is still new, as was the growth. I've seen this plant shed leaves. They gradually dry up and turn brown. This rapidly turned to black mush. You can see it in the first close up photo above... it's the leaf jutting sharply to the left.

As for over watering, it's barely possible. I'll ease up on the watering routine, however I understood this plant to like being kept damp. I have it in a coarse perlite/bark media with a little sphag moss mixed in for water retetion (this is brand new media, and so the bark doesn't yet retain much moisture). I'm watering it just as it's no long damp for the first few inches. I'll ease up, and see if this changes.

Paul Mc · #5 09-19-2013, 02:47 PM

Yeah, your comment about believing it liked moisture was what led me to overwatering as well. The one I had issues with started turning mushy as well. It was when I lightened up on water it resolved the issue for me personally, but it may be different for you. Keep us posted.

I would suggest using some Physan 20 on it though, just in case.

Paul McMahon
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