Masdevallia with spots on leaf underside

[Angel]

Hello to all orchid growers: I have just joined this lovely site. I was wandering if anyone could give me any input on my masdevallia. I have it growing outside in the spring, summer, and early fall. I mist daily or every other, and is in nice shady spot. I have some spots occuring on the underside of my leaves. Is this normal? Any suggestions! Thanks Angel

[King_of_orchid_growing:)]

Do you have a pic?

Right off the bat, I'd say no, it's not normal. But this is not a definitive answer.

A pic will be more helpful in determining what the spots could be.

[Ross]

Welcome to the board.

Black spots on Masdies often occur when the plants are subject to very warm temps. They prefer pretty cool temps (in low 70s) so the spots can be pretty common for Masdies that are not bred warm-tolerant (and even some that are warm-tolerant.)

[RosieC]

I've got the same problem but had not had chance to ask so I'm glad this has been asked.

Mine is probably the warmth thing, I'm pretty sure I'm not growing it cold enough.

I'll see if I can get a pic later today to see if that's what you think it is.

[Donald]

Interesting. I have the same problem with the four I have but it's never really bothered me much since the plants seem to be happy. The outside of the leaves are blemish free and all are presently in flower. This is what I have:
Masdevallia Angel Tang (veitchiana X tonduzii)
Masdevallia Red Baron (maculata x coccinea)
Masdevallia Rosemary (glandulosa x coccinea)
Masdevallia Ted Khoe (constricta X welischii) intermediate Cross: (urosalpinx x welischii)

[RosieC]

Mine seems happy enough as well, which is one reason I had not got round to asking the question.

Mine hasn't flowered yet but I've only had it a couple of months, it is growing new leaves though and does not seem weak or anything. Like you have said the leaves look fine on the top.

Mine if a veitchiana which I notice is in one of your crosses Donald.

Anyway I will try and get a pic tonight when I get home so we can see if it looks like the spots on yours.

[Donald]

Very nice website Ross, and good info.

[King_of_orchid_growing:)]

The spotting isn't usually fatal; for the most part it's unsightly.

This kind of spotting is temperature damage. Too hot or too cold, like Ross had said.

In the case of Masdevallias, it's a problem usually associated with being grown too warm for the ones that grow cooler.

However, once the temperatures exceed the plant's threshold of tolerance, the spotting will be much larger than the tiny to small ones that are kept under control by the plant. Failure to resolve the problem of temperature extremes for the plant will result in leaves dropping.

Masdevallia coccinea and Masdevallia vietchiana are pretty cool growing. If your hybrids have those in their bloodline, then they can tolerate temperatures as low as 36 F with no problems whatsoever provided they're protected from frost. The usual low end tolerance of these two plants should fall around 45 F. The top range of temperatures they can tolerate is around 85 F or 90 F. Ideally the high end temperatures for Masd coccinea and Masd vietchiana should be about 75 F.

[Angel]

Originally Posted by King_of_orchid_growing:)

Do you have a pic?

Right off the bat, I'd say no, it's not normal. But this is not a definitive answer.

A pic will be more helpful in determining what the spots could be.

I will get a picture asap, Thanks Angel

[Angel]

Originally Posted by King_of_orchid_growing:)

The spotting isn't usually fatal; for the most part it's unsightly.

This kind of spotting is temperature damage. Too hot or too cold, like Ross had said.

In the case of Masdevallias, it's a problem usually associated with being grown too warm for the ones that grow cooler.

However, once the temperatures exceed the plant's threshold of tolerance, the spotting will be much larger than the tiny to small ones that are kept under control by the plant. Failure to resolve the problem of temperature extremes for the plant will result in leaves dropping.

Masdevallia coccinea and Masdevallia vietchiana are pretty cool growing. If your hybrids have those in their bloodline, then they can tolerate temperatures as low as 36 F with no problems whatsoever provided they're protected from frost. The usual low end tolerance of these two plants should fall aroun 45 F. The top range of temperatures they can tolerate is around 85 F or 90 F. Ideally the temperatures for Masd coccinea and Masd vietchiana should be about 75 F.

I had the plant out all summer, we had some really hot weather, should have propably brought it in to the a/c.
I'll know better next summer. I'll try to post a pic asap. I only have one Masdevallia, it did not come with a tag, it has a yellow flower. I have what I consider a small amount of approx. 65 Orchids. Thanks Angel