concrete effects on orchids?

[Yukonphal]

Does concrete adversely effect orchids? I had a strange idea for mounting , but not sure if it would do more harm than good

[Bud]

I have seen concrete cinderblock cemented walls with Ivy clinging and thriving on them...maybe orchids might thrive on its porous surface because it retains water...

[james mickelso]

It would have no adverse effects on orchids mounted on it.

[Arenalbotanicalgarden]

Green(fresh) concrete could cause some issues(alkaline-ph 12).Once it's aged a bit, no biggie.
A freshly built pond will kill fish and plants if not cured a bit before putting them in. I suspect an orchid attempting to grab on would have the same problem.

[Ray]

Originally Posted by Arenalbotanicalgarden

Green(fresh) concrete could cause some issues(alkaline-ph 12).Once it's aged a bit, no biggie.
A freshly built pond will kill fish and plants if not cured a bit before putting them in. I suspect an orchid attempting to grab on would have the same problem.

Quite correct.

Often, the concrete is "passivated" with muriatic (hydrochloric) acid to strip the surface of free alkaline minerals.

Have you considered hypertufa? I'm sure you can find the formula on the web, but it's basically Portland cement and peat moss, with the latter lowering the pH sufficiently.

[tucker85]

A commercial grower here in South Florida has several orchids mounted on concrete blocks. They seem to grow very well.

Here's a picture I copied from another member that I tought was interesting.

[Ray]

Yeah, but that's some pretty old concrete.

[zxyqu]

Originally Posted by Ray

Yeah, but that's some pretty old concrete.

Haha... My thoughts exactly...

[Yukonphal]

There must be a way to "age" concrete quickly

[Arenalbotanicalgarden]

Originally Posted by Yukonphal

There must be a way to "age" concrete quickly

Bucket of acid water (pool acid-muriatic) soak.Always add acid to water. NEVER add water to acid.
I'd reckon you could sponge it down with vinegar(acetic acid) for a few days.