| The water holding capacities of mounts can be quite different. Of the three mounts you're considering treefern is has the best water holding capacity so it may be your best option if your humidity is low. Cork is somewhat water repellent and dries quickly so it may not be the best choice for you. The water holding capacity of woods like grape vine lies somewhere in between. The surface of the wood isn't as water repellent as cork so it can hold some water (particularly as it starts to decompose) but the water doesn't permeate throughout the mount as it does for treefern.
As for hardwood, it's perfectly fine to use as a mount. It's reasonably long lived and the water holding capacity is probably similar to grapevine. I suspect the info you've heard about hardwood breaking down quickly relates to its use as a potting medium, which is largely true. As a mount it, outlasts treefern and I have several orchids mounted on both hardwood fence palings and paperbark which are doing just fine. If the wood is fresh it may be worth weathering them for a few months before use.  |