Black rot or culture? and an ailing phrag

[lkg1323]

So a couple of my catts developed very small black tips on new growths. At first I thought they were sun burns, but they developed into more what looks like black rot. If I let them get bigger than a cm they are wet/mushy (rot). I've cut sections, only for it to come back as in the second photo, which is a dryer rot than previously.
Is this black rot? Is it imperative to remove the whole new growth?

And what causes this? Overwatering and/or lack of airflow?


I also (sigh) am seemingly killing my phrag pearcei. It looked great and it is now kind of sulking. A brown tip transformed into this whole yellow leaf in what seems like overnight.
I've also removed 2 smaller/newer leaves from this guy that appeared yellow/dead. I know it might have been a mistake - I am hoping this could be a Mg problem?

[King_of_orchid_growing:)]

Try reducing the amount of water the Catts are getting.

I would also not sit the Phrag in water. In the wild some of these Phrags grow on cliffs where there is a lot of moisture. The roots are not drowning in water. Phrags do need to be watered quite often, but they can dry out for brief periods of time in between watering. Instead, if the Phrag is in bark, I'd either put a thin layer of moss on top and water when the moss is dry, or you could try using dolomite pebbles or small chunks of limestone as a potting medium and put a thin layer of moss on top.

Btw, the cliffs are sometimes made out of limestone.

[Vanda lover]

It is hard to tell what might be wrong with the phrag but it could be a watering problem. I have my phrag in s/h in lava rock and it really loves it. It takes the guess work out of watering. I find it doesn't lake too much fertilizer. Leaves begin to yellow.

[Brooke]

What kind of light are they getting? Both orchids should have fairly high light.

Brooke

[lkg1323]

They're in a west window with a sheer shade. Really depends on the day how much light they're getting. It's been really dreary here for what seems like forever.

[plucker]

I think the catt problem in pic 2 maybe a calcium deficiency. Calcium is not translocatable and needs to be continually fed to the plants particularly when the new leads are forming. I find that green cats in particular suffer from this. Although I have a few others also which suffer.

The problem in pic 1 looks fungus related - maybe.

What is your water supply and do you supplement calcium?

Open for criticism here, happy to share thoughts.

[Gage]

At least the first picture is black rot. When you see this you should cut back until all of the infection is removed. I would then use peroxide on it, and once it dries you could put cinnamon on the cut to keep it dry.

[lkg1323]

I use tap water and a weak 20-10-20 just because it's what I have, no other supplements, which is what I was hoping was the phrags problem.

Thanks for the insights, I've since treated the black rots, and hoping with all my might that I haven't killed this phrag. I'm desperate to see a bloom from this guy down the line.

[quiltergal]

Phrags are very fussy about water quality. I have several and am using RO water on them. Distilled will work as well. They are also not heavy feeders. If your leaf tips turn black then you are over fertilizing. I stopped feeding them about a year ago and they all still bloomed just fine. The browning leaf (if it's a lower one) is probably just natural senescence. This it the time of year that old growths start to die back if they are going to. How many growths does this plant have, and/or is it starting any new ones?

[vjo]

I grow my Phrag. pearcei in a net pot with only spag. I keep it quite wet, and try not to ever let it dry out. It is grown in my cool basement under lights but over to the side as it does not like a lot of light. I do water with mostly rain water but I don't think that is actually needed it is just what I do. If you go to the ISPOE site it will tell you a little bit more about their culture....Jean