Ash wood for mounting

[Swamper]

Yes, where do you live?

[Ross]

Being a northerner myself and retired from the US Forest Service, I happen to know something about northern white ash (no doubt, your tree). It is not particularly rot prone, but constant moisture will shorten the life of the mount (unlike cedar). I would for sure strip the limb of the bark. The Emerald Ash borer may be present. It lives just under the bark in the cambian of the tree. Also, the bark has much less resistance to decay. There isn't any way to preserve the bark structure that would be safe for the orchids. How wet will the chunk of wood stay? Daily mistings or even dunkings are fine as long as the limb dries out overnight. I really think the whole project is worth undertaking as long as the bark is gone. To be on the safe side, I would air-dry the chunk you select for several months before mounting the orchids. There is no chemical in the wood that will cause harm to orchids.

[Ross]

Originally Posted by IraGlacialis

So a big issue is whether or not the log will rot and fall apart?

Ira, the only woods that won't rot and fall apart (in your lifetime), and are safe for mounting orchids, are any cedars, redwood, certain Mahogany species, and perhaps, Manzanita. When mounting an orchid, the clue to longevity of the mount is how dry it gets (wet/dry cycles). Just about any wood will rot when kept in hot/humid conditions where microorganisms can flourish. This isn't necessarily a bad thing, as long as you can remount the plant on a new chunk of wood.

[epiphyte78]

There's definitely more than one way to mount a Catt... but personally, I prefer to leave textured bark on the branches. It helps retain moisture and provides more root holds for the orchid to cling to.

Once the bark separates from the wood, the orchid roots enjoy the additional moisture to be found between the wood and bark. Also, I'm fairly certain that the gradual decomposition of the bark provides some nutrients for the orchid. Though I haven't the faintest idea which nutrients or in what quantity. I've never fertilized my orchids and they grow just fine.

In my experience, most wood mounts are going to last at least three times longer than the average orchid needs to be repotted. From personal experience, by the time the mount starts breaking down, it's about time for the orchid to be divided anyways and it's fairly easily removed from the broken down mount.

As a reference, here's a photo of a NOID Catt that I mounted a couple months ago on a very old dead wood fruit tree branch.

[IraGlacialis]

Originally Posted by Swamper

Yes, where do you live?

Missouri, near Kansas City, zone 5-6, which definately disqualifies a permanant tree mounting in the wintertime.

Originally Posted by Ross

Also, the bark has much less resistance to decay. There isn't any way to preserve the bark structure that would be safe for the orchids. How wet will the chunk of wood stay? Daily mistings or even dunkings are fine as long as the limb dries out overnight. I really think the whole project is worth undertaking as long as the bark is gone.

Frankly, I was choosing the branch (besides the fact it was going down anyways) due to the texture of the bark. I was think of doing a nurse-log type setting.
The form of watering I am planning on doing is daily morning mistings.

Originally Posted by Ross

Ira, the only woods that won't rot and fall apart (in your lifetime), and are safe for mounting orchids, are any cedars, redwood, certain Mahogany species, and perhaps, Manzanita. When mounting an orchid, the clue to longevity of the mount is how dry it gets (wet/dry cycles). Just about any wood will rot when kept in hot/humid conditions where microorganisms can flourish. This isn't necessarily a bad thing, as long as you can remount the plant on a new chunk of wood.

In that case, I am in luck. We have a lot of Eastern redceder trees on some property down south in central MO. If the bark begins degrading within a short amount of time, I will have a longterm solution to this scenario.
I was planning on having this as simply an experiment anyways.
Besides, in a college dorm, a desktop log is a lot more efficient than five pots of varying sizes.

BTW, I always thought ceders had chemicals in them that would inhibit growth.

[Ross]

Originally Posted by IraGlacialis

BTW, I always thought ceders had chemicals in them that would inhibit growth.

I have several mounts on Port Orford Cedar (way more strong than Eastern Red Cedar or White Cedar) and they take to it just fine. Lots of roots and great growth. I had heard that, but suspect it's an old wive's tale.