Any experience with this?

[orchidaddict789]

Has anyone tried diatomite as part (or all) of your orchid potting mix? How was your experience with it?

Just curious...I'm thinking of ingredients for my future orchid repots...

[LJA]

I don't use it, but I understand it's excellent for growing calcicolous paphs when the granulated form is mixed into the medium. Some growers also use it as a top dressing on other media.

(I think Dosal said on here once that she used it--maybe she or others can share their experiences...)

[peteMc]

I use the large size in the bottom of my potted chids as drainage, #3 in my phal mix, smaller stuff as top dressing...and I'm experimenting with it straight for a fine-rooted Aeranthes that likes it moist without being soggy. Bugs don't seem to like it much, and the plants do. So far, I'd have to say my experience with it is very good.

It is absorbent as heck, I've been flushing regularly to avoid salts build-up, but I suppose that's SOP for folks anyway. My feeling after seeing it watered every day for a while now is it has a very, very long pot life - another reason I'm trying it with Aerths, won't worry about it going stale or repotting frequently.

As far diatomite as a mineral source for the plant is concerned - silicates, or calcium, or some such - there's still some debate, and I'm no biochemist.

Hope it helps, enjoy.
p

[kewpie]

i use diatomite in my mix (with chc, perlite, charcoal, and sometimes sphag). ive got a couple of parvi paphs in the mix without sphag, ive got a couple of odontiodas in the mix with sphag, and ive got a couple of plants (a phrag and a zygo) growing in straight diatomite s/h style. the phrag and the zygo are both in spike as im typing. ive also got a blc. growing in a clay pot with diatomite+charcoal. its thriving, with lovely healthy roots, a couple of sheaths, and three new leads, two of which are a couple inches tall. i love this stuff.

when i bought my zygo, i unpotted and found that it had a rootless stolon and not many viable roots on the main plant. anyway, i put the stolon in its own little s/h pot, and planted the zygo in a chc mix (without diatomite). after a few months, i accidentally knocked the s/h pot over while trying to water. i found that the little guy was putting out roots like crazy. there was a ring of roots, all of which initiated above the diatomite. they were thin-looking, thinner than oncidium-sized nubs to begin with. but once they reached into the diatomite, they became thick phal-sized roots. there were also root hairs!! anyway, after seeing that, i repotted the mother plant into diatomite with s/h, and its now putting up a spike. i highly, highly recommend it.