My Masdevallia Venusta keeps dropping good leaves.

[Waverley]

Two years ago I bought a small clump of Masdevallia Venusta as 'grow on' material. I potted it in water retentive compost over a free draining base in the bottom half of the pot. The plant did well in the first year and then half of it died away. I repotted and it now produces one new leaf at a time periodically. However at the same time it often loses one leaf and so is not making any growth progress. The leaf goes yellowish at the base then breaks cleanly off just above compost level. The tip end of the leaf continues to look pretty good and green until it falls. I water it once it becomes near dry and now that it is winter keep it in a heated propagator at 17C. What am I doing wrong?
Comments appreciated thanks.

[kmarch]

Originally Posted by Waverley

I water it once it becomes near dry ...

I think this is your problem. It sounds like you're growing it like some of the other commonly grown orchids. Masdevallias have different needs. They should always be kept moist. They are also cool growing orchids and can comfortably tolerate temps down into the 10-15C range (50sF). They like a lot of humidity, as high as you can give them. If you have not already done so, get a culture sheet on Masdevallias (AOS | Members Only Area). Give it a read and if you have any questions, just ask us.

[koshki]

I'm also concerned about the "water retentive compost". Not sure what this means, or if it is appropriate for orchids.

[kmarch]

Originally Posted by koshki

I'm also concerned about the "water retentive compost". Not sure what this means, or if it is appropriate for orchids.

Some orchids must have a lot of moisture while a lot of moisture is very detrimental to other orchids. The question isn't whether it is appropriate for orchids or not, there are so many different kinds of orchids form all over the world with many different cultural requirements. The question is "is it appropriate for Masdevallias?"

[Brooke]

Welcome to the forum Waverly, hope we can help.

I had to look up the venusta since I wasn't familiar with it and it is now Masd. amabilis. The amabilis is a very very cool growing masdie and in the winter the average temps are upper 50's, lows in the upper 30's. In the summer temps are upper 60's and low 40's. It needs constant moisture in the growing season - April to Nov. and then a drier season during the winter.

I am guessing, but it sounds like in the beginning you had an unbloomed seedling which has a "clump" growing habit but as it aged, it has taken on the adult habit. Your leaf loss sounds like you are getting a slight bacterial infection in the papery growth at the base of the stem. This will cause the stem to turn yellow and fall off while the top part is still green.

This species needs strong air movement, high humidity, cool temps year round and can take more light than most masdies. Good luck with it, I love this species but I don't have the conditions to grow it. Please post pics when it blooms for you.

Brooke

[Waverley]

Thank you Brooke. The plant was bought at a national show from a guy who spoke little English as a small clump of young plants and certainly unbloomed. During last summer it was kept near continously damp routed but in a dry air environment. A lightly mist sprayed it most days before going to work but then nobody was around to early evening so that was all the attention it got. Once a fortnight the spray had very dilute proprietry orchid feed in it.

The compost is fine bark and moss with a little perlite. The problem commenced during the summer. It had been producing new growth on one side but loosing it on the other so in the Autumn I split the healthy side away from the decaying side and repotted. At first all seeemed well.

Since late autumn it has been in an old fish tank with glass cover and natural light plus a heat mat. The temperature range is 52F-76F and I keep the gravel just wet and the compost moist to the touch. Now the problem has struck again - since posting my problem the largest recently grown leaf has collapsed with the same problem. At the same time it has two new, but still small very healthy looking, green leaves. I did once notice a small fly come away from somewhere near the plant base when I lifted it up.

Could air flow be a problem - perhaps yes. Would it be worth repotting again, using some type of pest or bacterial control measure, or just take it out of the enclosed 'propogator' (other orchids seem happy there) and keep the top in drier and more freely moving air.

Thanks once again for all the suggestions.

[Bolero]

This is a cool growing species as mentioned earlier in the thread. I am just looking up my Masdevallias book as I'm not familiar with this species.

Basically it's saying that by being cool that it will tolerate minimums between 7 and 12C at night and daytime temps of a range of 10 to 17C. I think it will tolerate slightly lower than the 7C and will tolerate higher than the 17C but these would be ideal for this plant. If it's constantly sitting at 17C then this could be to high. When talking about temp ranges for Masdevallias they fall inside different ranges so cool for a Masdevallia will be different to cool for a paph or cattleya for instance.

Air flow as stated above is extremely important and I only use sphagnum moss. I have used peat moss, coconut and bark but I now refuse anything other than sphagnum moss to grow them in but it depends on your conditions. If the moss stays to wet for to long then you would be having problems even though they enjoy moisture more than most other orchids.

[Brooke]

I would definitely remove it from the tank and increase the air flow. This species likes it very cool and breezy.

The little fly was probably a fungus gnat, nothing that would cause your plant a problem.

If the leaf drop continues, use 3% hydrogen peroxide as a pour through the pot but hopefully increased air movement will stop the problem.

Brooke

[Schlyne]

I concur on the air flow. I lost my first madsie to a problem similar to this and later figured out that it probably wasn't getting enough air flow.

[ArtGeekMark]

I have two masdevallias; a small Ted Khoe & a larger Anne Leggette 'Mauna Loa'. The Khoe I bought early last May from the CPaOS show at PSU, the Leggette I rescued from our clearance table at work for 5 bucks after it went out of bloom & had some sun damage being in a hot greenhouse. Last week the Khoe started dropping leaves, yesterday it dropped its last two leaves. I checked the roots and they appear healthy fleshy and viable, I couldn't see signs of bact/fungal problems to the eye but after reading this thread I'll try the peroxide thing! I'm just frustrated because I thought I set up the right conditions for them & the $20 Khoe is spazing out while the beaten up abused $5 clearance rescue Leggette has rebounded and thrived while they were under the same conditions. Like one of ya'll mentioned, even amungst other masdevallias, not just other orchids in general, can have such different needs! What Leggette lovea Khoe certainly seema to hate, or thw Khoe indeed may have a bact/fungal problem not noticable to the naked eye. Any additional pointers are greatly appriciated!

[Orchidementia]

Originally Posted by ArtGeekMark

I have two masdevallias; a small Ted Khoe & a larger Anne Leggette 'Mauna Loa'. The Khoe I bought early last May from the CPaOS show at PSU, the Leggette I rescued from our clearance table at work for 5 bucks after it went out of bloom & had some sun damage being in a hot greenhouse. Last week the Khoe started dropping leaves, yesterday it dropped its last two leaves. I checked the roots and they appear healthy fleshy and viable, I couldn't see signs of bact/fungal problems to the eye but after reading this thread I'll try the peroxide thing! I'm just frustrated because I thought I set up the right conditions for them & the $20 Khoe is spazing out while the beaten up abused $5 clearance rescue Leggette has rebounded and thrived while they were under the same conditions. Like one of ya'll mentioned, even amungst other masdevallias, not just other orchids in general, can have such different needs! What Leggette lovea Khoe certainly seema to hate, or thw Khoe indeed may have a bact/fungal problem not noticable to the naked eye. Any additional pointers are greatly appriciated!

I have quite a few Khoes (started out with one but it got so big I divided it). I live in the SF Bay, so my outdoor conditions are perfect for masdies, which are: cool, high air movement, kept moist (well, I water a lot in the summer because we're in a drought then), EXCELLENT drainage and fairly high light - no direct noon sun, but bright.

I grow mine in either fine bark mix (I make it from bark, pumice, charcoal and perlite) or sphag; whatever I have handy. Mine are out in temps as low as 35 and as high as 98 (but with cool nights, constant air movement and always, always moist).

They like being very moist but dislike standing in water, so be sure they drain very well. Some people use packing peanuts; I use hydroton pellets. I also like clay pots for their 'breathing,' even though that means I may have to water more.

Others may have more/better advice! Good luck!