Strange black spots on Cattleya - Orchid Board

emartinm28 · #1 10-13-2021, 06:42 PM

Hi all, I received a cattleya as a gift from my boyfriend and made the mistake of repotting too soon, setting the orchid back. It developed black rot on its newest pseudobulb, and in the end i decided to cut it off and apply an antifungal. That was in May. It’s now October and the orchid has recovered a bit and made new roots and started a new growth. Today however out of nowhere I noticed these black spots. Can anyone identify? What should I do? I really don’t want to lose this one. Thank you in advance.
Edit: i don’t know how to post pictures here. My post keeps getting denied

rbarata · #2 10-13-2021, 07:31 PM

There's a rule of 5 posts before being allowed to post photos. You can upload it to any 3rd party photo sharing site and post the link here.

Roberta · #3 10-13-2021, 07:46 PM

Just don't cut off any more pseudobulbs! Before you cut anything, read the thread about Worrying Orchids to Death
Worrying orchids to death

Along with posting a photo... rbarata's suggestion gets around the 5-posts limit very nicely and also lets you post larger photos... tell us more about your conditions. What is the temperature range that the orchid has experienced? What medium? Light? Is there good air movement around the plant? What are your watering practices - frequency, quantity, etc All of these factors can be involved with problems - and solutions.

emartinm28 · #4 10-13-2021, 08:04 PM

Thank you for the info! I’ll see about posting that picture, but for now the orchid experiences temperatures ranging from the mid 60s to the high 70s, I use bark with a little sphagnum moss, the orchid is near a south facing window getting a lot of light, there is excellent air movement in my opinion, and I completely soak the pot whenever the medium has dried out completely[COLOR="Silver"]

---------- Post added at 05:04 PM ---------- Previous post was at 05:01 PM ----------

Shared album - Eli Martinez - Google Photos

My Green Pets · #5 10-13-2021, 08:09 PM

Is that temperature related? Cold damage? Just a guess.

Roberta · #6 10-13-2021, 08:10 PM

That actually looks to me like sunburn... the lighter dark spot on the leaf behind it may have been shaded a bit by the more severely-affected one. It can take awhile for sunburn damage to appear, but a blast of really bright sunlight (even for a short time) can create a nasty hot spot. If that's what it is, won't hurt the plant (or affect anything else), just look unsightly. (I have toasted a few in my "career"...) - For me, that sort of thing happens most often in March when the sun suddenly clears the house or a tree as it moves higher in the sky, or September/October when the sun shifts south and sneaks under the shade cloth hitting and area that previously was shaded.

emartinm28 · #7 10-13-2021, 08:58 PM

Thank you so much! I’ll move it away from the window, your advice has been very helpful and a relief

Roberta · #8 10-13-2021, 09:03 PM

Sounds like a plan - or get a sheer curtain for the window to "take the edge off" . Catts need bright light, but it's the sudden blast that causes the damage. If you feel a leaf and it hot to the touch, you can catch it before damage happens. That sheer curtain can diffuse the light enough that you don't get that local heating.

My Green Pets · #9 10-14-2021, 01:02 AM

You can also buy plastic cling film, normally used for privacy, with fancy designs (or just lightly frosted) that adheres to the glass just by spraying soapy water on it. Peels off easily if needed, looks nice, and will 'take the edge off' as Roberta says.