Phal NOID with Dry Black Spots Under Leaves

[blackvine]

Hi, all - I have a Phal NOID that has a fairly large (about 1 and 1/2" by 3/4") black spot under its lowest leaf. Right next to that is a grayish spot. Both are dry and neither shows on the upper part of the leaf. I noticed it about a week ago and it has not spread.

Background: I received the orchid about a year ago as a gift. It did well. It was in all sphag, but I just adjusted my watering to let it dry almost out, then soak. In June, it threw out a new leaf that is now bigger than the others. (A good sign.) In September, I thought it may be happier in CHC with a little sphag, so I repotted in 2/3 CHC, 1/3 sphag, and a half handful of charcoal. It has a new root as of about a week ago (most noticeable in the 2nd pic, at the base.)

Should I worry about this? I'm a bit new and not too worried, but . . . I may be wholly wrong!

[WaterWitchin]

To me, it looks more like a mechanical injury (like leaf was rubbing on lip of pot). Hard to tell, since it's recently repotted and appears to be tied up with a bit of twine.

I am very far from an orchid expert, so hopefully someone more knowledgeable will chime in. I also tend to plant my phals a bit deeper in the pot. Whether that's right or wrong, I don't know. It works for me.

Out of curiosity, why ARE they all tied up with a bit of twine?

[blackvine]

Originally Posted by WaterWitchin

Out of curiosity, why ARE they all tied up with a bit of twine?

HI, WaterWitchin - well, most of my orchids are tied up because several months ago, I became sold on CHC and decided to repot just about everything in, adding or not adding sphag, dependent on how much the individual plant likes (or not) drying out. My phals are in about 2/3 CHC and 1/3 sphag; Catts: no sphag, all CHC. They are all staked to get them established in their pots, then I'll remove the stakes. I use the twine because I feel like fishing line cuts them. I was told, though, that the twine will decompose and may cause disease, so I am going through my 50ish plants, retying with nylons.

---------- Post added at 12:26 PM ---------- Previous post was at 12:24 PM ----------

Originally Posted by WaterWitchin

To me, it looks more like a mechanical injury (like leaf was rubbing on lip of pot). Hard to tell, since it's recently repotted and appears to be tied up with a bit of twine.

Yep, you may be right - it may have rubbed against the old pot. Well, they're potted high because I have a bit of trouble potting and I'd rather get them too high than too deep.

[james mickelso]

See staugorchidsociety.com. This looks like bacterial brown spot. I have it on some of my catts right now. I control it fairly well by keeping all water off the leaves.

[blackvine]

James, thank you. It may be that, but is totally dry, has not broken through to the upper side of leaf. I will watch it.

[james mickelso]

The plant is usually capable of fighting it. Right at the margins is were the fight is taking place and that slim one might be suspect. Keep an eye on it and if it continues to spread, cut out that par of the leaf and dust with powdered cinnamon.

[NYCorchidman]

My opinion is to cut that entire leaf off and stop worrying about it.
Trust me, the plant will not be negatively affected by having one leaf removed.

I don't think it looks like a mechanical damage. It never shows up as black area on phals leaves if it is mechanical damage.
If you don't trust me, scratch small area of one of the leaves and wait for a couple of weeks.
It will not look the same.

[WeirdGuySeattle]

Looks like water or mechanical damage to me. I like the theory that it bumped against the old pot. It doesn't appear to be harming the rest of the leaf all that much .

[blackvine]

Thanks, all! I'm no longer worried as it has not changed at all. I'd prefer not to cut the leaf off because every live leaf helps the rest of the plant, ie, via photosythesis. I don't cut leaves unless they are truly diseased or dead.