TOLUMNIA - HOW TO MOUNT AND WHAT KIND OF CARE? - Orchid Board

Margit · #1 03-05-2008, 03:22 AM

Hi there,
A couple of weeks ago I purchased a Tolumnia Red Berry at a garden show.
Reading up on it a little more I find that it does not like to be kept too wet.

Having read this in several places, I am starting to consider mounting it onto bark.
I have never mounted an orchid and I am not sure how to care for it afterward.

What should the size of the piece of bark be, how much sphagnum moss do I attach under the plant (if any), do I only spray the roots when watering .... ?
So many questions

I would appreciate input to help me make the right desicion - to mount or not to mount?
Thank you!

Orchidophile · #2 03-05-2008, 09:55 AM

Hi Margit, I also purchased the same plant a few weeks ago I havent done anything to mine yet even though it is bare root. You could keep it in a pot but with a very free flowing mix so no water stands. If you mount it I would go with cork, treefern or even a slab of cedar about 5" x 3". put a layer of sphagnum, then put the plant on that, then put another layer of sphagnum so you cant see any roots but dont let it cover the leaves and then I usually use fishing line to tie it down. Just spray it daily or dunk it

Ray · #3 03-05-2008, 10:02 AM

Tolumnia species are native to the Caribbean, where they get frequent rains, but lots of warm breezes to quickly dry them out. The trick is to mimic that.

They are not big plants, so the mount does not have to be large. I have them on 2" x 4" and 6" x 9" pieces of cork or Epiweb, on bark-free maple branches collected from my yard, in wooden baskets of loose coconut husk fiber, and in 1" clay pots with no medium.

When you mount, it's better to place the moss over the roots, not under them, but in the case of tolumnias, I recommend against using moss, as the roots prefer to dry more rapidly than it allows. Instead, I spread strands of coco fiber over them, stapling it to the cork bark until the plant grabs hold.

epiphyte78 · #4 03-05-2008, 03:33 PM

It’s considerably easier to over water potted orchids than it is too over water mounted orchids… so I vote for mounting. The amount of moss you use depends on A. the type of orchid B. how frequently and deeply you can water the mounted orchid C. your environment and D. the type of mount you select. If it’s an orchid that likes to dry out between watering and you can water everyday and maintain a warm, high humidity environment and the mount is horizontally oriented and has a flat, highly textured/grooved and moisture retaining surface (cork doesn't retain moisture so well) then you could get away with using no moss.

The Santa Barbara Orchid Estate doesn't use any moss when they mount their orchids while Andy's Orchids (their specialty is mounted orchids) uses a handful of moss for a medium size orchid.

You might want to try a simple experiment. Grab two each of all your possible mounts and place the same amount of moss on one of each mount type. Line up the mounts and water them the same amount and time how long it takes each mount to completely dry out. That should give you a very rough idea of how often you’d have to water if you used or didn’t use moss.

If you do decide to use moss make sure you compact it down so it is round and flat so that only the bottom of the rhizome is touching the moss. For small orchids I first put the moss on the mount and then tie string around and around the moss and mount so that the moss is completely flattened against the mount. Then I place the orchid directly on top of the moss so that only the bottom of the rhizome is in direct contact with the moss. I've found that on the rare occasion rot does occur in a mounted orchid it's usually because there was some moist moss that was kept in constant contact with a portion of the cane or pseudobulb or it covered where the new growth emerges from the orchid.

When you water it's important to thoroughly soak your orchid. I have an overhead sprinkler/mister system that I leave running for around 20 to 30 minutes that drenches my mounted orchids. Mounted orchids need much more water than potted orchids and newly mounted orchids need more water than mounted orchids that have established root systems. Given that I have an overhead sprinkler system, the whole orchid gets wet, not just the roots. Since all my orchids receive the same amount of water I use mount type/orientation, quantity of moss, and quantity of shade to help the moisture lovers stay moist longer.

In winter I water in the early morning so that the orchids are completely dry by the time the sun goes down and it gets cold. As spring approaches and the weather warms up I water gradually later and later and by the time the coldest night temperature is around 55 degrees I start watering in the evenings. This way the mounted orchids stay moist longer. When it gets super hot I'll water them for a bit during midday. Generally speaking, cold and moist encourages rot while warm and moist encourages new growth. But again, it really depends on the orchid.

When you mount your orchid make sure you securely fasten it to the mount. If it wiggle wobbles then new root tips can be damaged and broken which will severely hamper new growth. Most people use 12 lb fishing line that they tightly loop several times over the orchid and its mount. To tie it off they "under over" 3-4 times and then tie several square knots.

I just use regular synthetic string because I can cinch it down super tight without worrying about it slicing through the orchid. Basically I tie a slip knot on one end, loop the other end around and over the orchid and its mount and then through the hole of the slip knot. When I pull the string, the slip knot hole closes over it so that when I cinch it down constant tension is maintained. I loop the remaining string tightly over the orchid and mount several times and then estimate where I need to tie a new slip knot on the looping string. I place the left over string from the first slip knot (we'll call it Part A) through the hole of the second slip knot and then pull Part A back towards the first slip knot. When I pull it, the hole of the second slip knot closes over Part A and constant tension is maintained. I then cinch it down until it is completely tight. If I estimated the location of the second slip knot correctly, maximum tension is reached before the second slip knot reaches the first slip knot. Then I use square knots to tie off the ends. Wish I could say it’s easier than it sounds but it takes quite a bit of practice to get it right…unless you’re familiar with knots. The beauty of this technique is that constant tension is maintained via the slip knots.

Best of success!

plantaholic · #5 10-21-2015, 03:11 PM

Hi, I just got two tolumnia babies last night. They're potted in tiny plastic pots in a small bark mix. They were moist when I got them so didn't water last night. So far today, I've only misted them. I'm really nervous about these. I grow oncidiums well so thought these might be a fun new thing to try. I've read everything and that just makes me more nervous. So water them? Mist them?

estación seca · #6 10-21-2015, 03:47 PM

Don't fear! You can grow them.

You just have to mist a lot with a spray bottle, not soak them. Your aim is to dampen the roots without wetting the bark too much. The roots need to be wet frequently, then dry fast. In nature they get wet with dew every night, and rained on frequently, but they grow on twigs and tree branches, so they dry out fast.

They need a lot of light, but your summer sun will be too hot. Fall and winter sun will be great. Seedling Tolumnias take a surprising amount of light but they will cook with too much.

I think your humidity is also very low in eastern Washington? I grow mine in a room with a lot of other plants, and humidity in that room is 40%-60% even when it's under 10% outside.

I have a beautiful seedling T. variegata from Olympic Orchids, mounted on a piece of driftwood. There is a bundle of sphagnum at the bottom of the mount, but the plant has almost all its roots above that on the wood. Even in my climate it is doing OK with misting at least twice a day.

If the bark in your little pots dries out within a few hours of spritzing, they will be fine in there. Just give one or two spritzes to wet the roots. You can repeat as often as the plant dries out, but you probably don't want to sit there all day worrying about the thing.

If the bark doesn't dry out within a few hours of spritzing, I would strongly consider repotting with some new, very coarse bark, or even mounting on a piece of wood. People also grow them just sitting in a tiny clay pot with no other medium. Read above in this thread for some excellent mounting instructions. There is also good information from the American Orchid Society:

Tolumnia Culture - American Orchid Society

plantaholic · #7 10-21-2015, 03:58 PM

Thanks! Yes, we do live in the desert here. Not too much humidity in the house but I've been able to make a few things bloom. I've been following your advice on the vandas in a vase. So far its still alive...

estación seca · #8 10-21-2015, 04:01 PM

I'm finding I should water my vandas even more than I thought before. In addition to spraying their roots twice a day, I fill their vases and soak them for 4-6 hours every 2-3 days. I noticed they often make quite a bit of growth during an overnight soak.

Orchid Whisperer · #9 10-21-2015, 05:05 PM

I've never succeeded with Tolumnia. However . . .

At our orchid society meeting last weekend, a new member, who has only been growing orchids a couple years, came in with some plants, including an 8 or 10-inch diameter (~20 - 25 cm) pot filled with well-established, healthy, growing and blooming Tolumnias. Her 'secret' - very coarse bark, and only watering the bark here and there, never soaking the medium, never getting the leaves wet.

One of the long time members of our OS said he would not change a thing regarding how they were grown.

The take-away lessons for me are that if I try Tolumnia again, I should (1) provide perfect drainage, and (2) keep the leaves dry. Maybe the second one you can skip if your humidity is low and ventilation/air flow are high. Oh, and (3) there is PLENTY you can learn from beginners.

silken · #10 10-21-2015, 07:46 PM

I have two Tolumnias that are mounted on a clay log. I have a bit of sphagnum behind the base and roots, but most of the active roots are just in front of that and bare. I water mine (roots only every other day or so. I had them under misters when we were away part of the summer. Both have new growths and a spike each so they seem happy. My thought is these can do fine with minimal watering. I just don't get a chance to water every day. For winter I have them under T5 lights but in summer they get quite a bit of sun in the greenhouse with 50% ( I think) shade cloth. I think they are quite adaptable and overwatering is likely the most common reason for people killing theirs.