Brown/black spots on Masd. coccinea

[Gaia]

I recently purchased 2 Masdevallia coccinea from an orchid grower online from TradeMe (our take on eBay), and he sent me 4 instead. Thought it was lovely, that he had lots laying around and just wanted to clear some out. Then I went to his nursery and he mentioned that he sourced them in every year to sell because they don't grow well in that area. thought it was weird then that he sent me extras when he purchases them from someone else and still had some others for sale.

Anyway, 3 out of the 4 have a lot of growth, but also horrible spots. some of the spots are just brown circles, and others are light brown puckerings on the underside of the leaf. then theres also what seems to be the leaf tip dying back.

did some research, and thought it was fungal, so i've sprayed them with neem oil. i live in a one room apartment, and only have one window where light comes through, so most of my orchids (minus the phals) are on a table near that. So, those three have to live outside/garage while they stink (got a huge surprise when i opened the bottle, big chunks of neem tree and its a horrid smell).

After more research on here, I'm now unsure if its fungal and might just be the growing conditions they were in before I got them? The other one I got thats spotless is much younger, with less than half the leaves and looks healthy. And the spotty ones have one/two new growths coming through as well. I have another one that I got last year (that I nearly killed before I found out they like to be crowded :/) that seems happy, spot free (and resilient...).

Should I keep going with the fungicide, or do you think it is just an environmental issue? Don't want to bring them back inside if they're going to infect some of the new plants I recently got. But don't want to be mean and leave them outside, as its been reaching 0 degrees Celsius (32 degrees Fahrenheit) in my area recently.

[stefpix]

some could be sunburn. I have a pleura that has 2 leaves with round black spots like one of your photos and it happened when I put it closer to the window.
Only 2 old leaves have those and on one side.

But you have one leaf with different kind of spots. Maybe i would put some sulfur paste on those

[Andre]

Hi,
I have had similar experiences with both of those Masd. species and that type of spotting can be fungal, but is I find more of cultural problem. They both do lot like to grow warm, and need quite a bit of humidity. I used to grow mine outside here in Vancouver Canada from late April until late September, but lost multiple plants over one of our 2 day "Heat waves" one year.
There is a great article on the genus in the orchid digest or sites online. I'm sure there are certain clones that may be more resilient, but now I grow species that are not as fussy.

Good luck... I hope they recover for you.

Andre

[silken]

I have a Masd. Machu Pichu which is half Masd. coccinea. Last summer it spotted similar to yours only worse. It grew right beside another Masdie with other parentage and that one didn't spot at all. I am quite sure it was heat stress. The spots never spread and all the new growth is clear and healthy looking. Masd. coccinea is a very cool grower with year round temps at a maximum of 55 to 58F according to OrchidWiz. I have no problem keeping it cool in winter, but in summer it grows somewhat warmer where I keep it. I would watch it carefully but suspect it was stress induced.