Grey leaves on old Dendrobium nobile and damaged leaves on phalaenopsis

[jackiebrown]

Hello!
I'm new here and i'm from Italy

I'm trying to recover an old Dendrobium orchid, it's my mother-in-law plant that she never took care of (it stayed outside on the balcony in west exposure and i think she never repotted it ).
Probably tomorrow the bark order i made from amazon will be delivered, so i'm going to move the orchid in a larger pot with new bark.

I didn't check the roots yet but i noticed that there are a couple of stems with grey leaves, i'm not able to say if they're dead leaves or there's some kind of desease.

A couple of days ago i bought a phalaenopsis from a supermarket near here... the roots are ok, there are a couple of flours but i noticed that a couple of leaves were damaged; i cut them with disinfected scissors.
It seems there was a sun burn on them but i'm not sure of it, i post the pic of the cut leaf so you can see it and express your opinion

I hope the pictures link will work.
Thank you in advance and sorry for my bad english

Dendrobium and phalaenopsis pics

[Blueszz]

Welcome!

Too bad, I can't access the photo's on your Google Drive. I use IMGUR for posting pictures here.
To answer your questions we need the pictures though.

Maybe others have an easier solution for posting pictures here than IMGUR. IMGUR seems to work fine for me on PC but not when I'm on mobile.

[jackiebrown]

Thank you for your answer, i uploaded the pics on imgur and it seems to be working properly now

[estación seca]

Welcome!

The Den. appears to have spider mite damage. Spray the entire plant, pot and top of the medium with 70% alcohol, or with a solution of insecticidal soap. Do it soon; mites spread rapidly.

I would not cut any leaves from a Phalaenopsis. They yellow and drop off on their own when they get older. That might have been happening here. Other possible causes might be too much light or insufficient water. Insufficient water can be caused by not watering enough, or by a poor root system. Many Phals. are grown in warm, humid greenhouses. They do not carry as many leaves in a cooler, less humid home environment. Having three to four leaves is common. They often drop a leaf or two not long after arriving home, if they had more at purchase.

I would not repot the Den. until it begins making new roots. A good time to repot is when new roots are 1-2 millimeters long. That usually happens a short while after new growth begins, which might not be until next Spring. If you repot now, many of the roots will be damaged, no matter how careful you may be. It would have trouble taking up water until it makes new roots, and might die. Instead, after treatment for mites, I would water carefully, letting it get almost but not completely dry between waterings. If it begins making new growth this season you will be able to repot. In Winter you can let it get dry between waterings, but don't let it dry for more than a few days. If you can give it nights below 13C / 55 F for six weeks in Winter, it is big enough to flower next spring. Also, the plant has been somewhat underwatered, as shown by the wrinkled newest leaves. And for flowering, do not fertilize these after mid to late Summer, perhaps about now. Wait until you see new growths at the base in Spring to fertilize.

Phalaenopsis can make roots all year if temperatures are good. If this one hasn't been repotted in a while, now would be the time to do that, and look at the roots.

In either case, I strongly recommend not to cut off any roots when you repot orchids. You really can't tell which are alive and which are dead.