Blackening leaf tips of Stanhopea embreii - what could be the cause?
 

Hello everyone!

This will be my first post on the Orchid Board, so please be understanding. :)

A few months ago I purchased an adult, healthy specimen of Stanhopea embreei, which I placed in a hanging basket in a substrate made of a mixture of pine bark, perlite and sphagnum.

Unfortunately, after a few weeks, the tips of my Stanhopea's leaves began to turn black and split, and the young leaves also began to turn yellow. I tried to determine what could be the cause, whether it is a fungal/bacterial infection or whether it is caused by improper conditions. My Stanhopea hangs by a window with a north exposure, in a room with a temperature of 22 - 25°C, humidity of 50 - 60%, every morning I intensively spray the sphagnum in which it grows with water.

Hence my question - has anyone encountered such a problem and what could be its cause? Below I am attaching a few illustrative photos.

Thank you in advance for your help. :blushing:

Welcome!

I don't grow this genus, but I typically see the blackened edges on leaves in my own collection when the plant is either kept too warm, not humid enough, or a combination, and the damage to your plant's leaves look like the same damage to me (please chip in someone else if you think it may be something bacterial or viral).

Orchid species says it grows in cloud forests in cold to warm temps, and based on your description, my first instinct would be that the humidity is a bit low, but it could also be about how close to the window the plant is. The heat right behind the glass can be quite a bit warmer than other parts of your room, but also, it looks like the window may be a velux window? If it is, and the window is tilted, it will receive more direct overhead light than your ordinary vertical northern-facing window.

Finding the right spot for your orchid can be a bit of trial and error, but personally, I would start with pulling it back from the window a little bit if it's a velux window, or it's right behind the glass.

Welcome to the Orchid Board!

What kind of water are you using? This could also be mineral buildup, which shows as leaf tip damage.

Stanhopeas do like to stay wet. I don't think the temperature is a problem. Maybe a little cool but within range. I get "ugly leaves" on my Stanhopeas, don't worry about it much... force of nature. (I grow them outside since I live in a frost-free area). Your plant is still quite young. It needs to be moved to a basket with bigger holes very soon... flowers grow downward, the spikes need to escape. (I use wire baskets lined with sphagnum for the larger plants, plastic baskets with holes of 2 cm or so for the smaller ones, and cut the basket when I see a spike getting caught).

This is how it looks in bloom (basket is above the plant, spike coming downwards)

I use rainwater.

---------- Post added at 06:13 PM ---------- Previous post was at 06:10 PM ----------

Thank you for all your advices :)

If you just repotted it, there was also maybe a bit of root damage, that is making it harder for some growths to take up water. Not a long term problem, it will recover. These really don't like having roots disturbed, and may sulk a little.