Question on lithophytes and lime

[OrchidThief79]

"Coral rock" is the calcium carbonate skeleton that remains when marine corals die. Calcium carbonate is also the main constituent of lime. So coral would be a fine lithophyte mounting material I think. The problem is that all coral has at some point been submerged in the ocean, and it is porous, so salts have accumulated in it that would damage roots. But I would think that a thorough boiling and rinsing would remove most of the salt.

[dbvogt]

Originally Posted by OrchidThief79

"Coral rock" is the calcium carbonate skeleton that remains when marine corals die. Calcium carbonate is also the main constituent of lime. So coral would be a fine lithophyte mounting material I think. The problem is that all coral has at some point been submerged in the ocean, and it is porous, so salts have accumulated in it that would damage roots. But I would think that a thorough boiling and rinsing would remove most of the salt.

Good point. There are firms that sell coral from excavations and I'm tempted to experiment. I just have never seen a source for orchids that are specifically designated as lithophytes. Lots of pricey hybrids though.

[purpleplantman]

lime helps to counteract excessive acidity in media, helps reduce fungal infection via pH effects, supplies calcium to plants & helps strengthen tissues. Certain plants love it , others hate it (Paph delenatii), many are indifferent to its' use ie. can't change growth, only the environment. I have supressed fungal attack on cymbidium leaves by dusting with dolomite after watering.

[purpleplantman]

PS. shellgrit or similar can attract snails looking a calcium fix to grow their shells.

[dbvogt]

Originally Posted by purpleplantman

PS. shellgrit or similar can attract snails looking a calcium fix to grow their shells.

Maybe I should spread some Oscal-D pills around the perimeter

I took the plunge and ordered a couple of coral pieces and a Laelia glodeniana from Andy's Orchids. I stuffed some sphagnum in a few holes and set the plant in an indentation. The plant is supposed to like sun and be watered twice a week. It was potted in a 2 in. pot with gravel so it might be happy with the moss. No changes yet after a week but based on my limited experience, it takes a while for any obvious changes after repotting. One author (William Cullina) says it takes a season for some orchids to recover from repotting.

BTW, I bought a couple of plants at HD in those white net bags. They looked pretty lame but within a week, they were sending out beautiful new roots and growing. Maybe they were glad to get out of there. Growing "an orchid" is relatively easy. Growing more than one kind starts to get complicated.

[glengary54]

Originally Posted by dbvogt

Growing more than one kind starts to get complicated.

Not really, I grow many different genera in the same space and they are all on the same watering schedule, the only difference is the medium that they are planted in. I mix my own medium to suit the needs of the plants, keeping my watering habits in mind.

The only plants that get treated differently are my mounted plants that get watered every day sometimes (in the heat of summer) more often.

The real challenge comes in the winter, trying to remember which stay on a regular watering program, which want less water, which require little to no water at all, which need to be kept above a certain temp and which need lower temps.

Really not complicated at all.

[Ray]

Be very careful with calcium additions.

Yes, some lithophytes grow on limestone, but they may not necessarily be ON the limestone, but in the detritus and leaf litter in the cracks in the limestone.

Such natural limestone deposits are very slow to dissolve, so while they do release the calcium into the root environment, it is a very low dosage, and doesn't boost the pH enough to overwhelm the acidity of decomposing vegetation. If you use a water-soluble additive, I think you'll be pushing it too far. You're much better off with a fertilizer containing the calcium and magnesium (they work better together) or top-dressing with slow-to-dissolve stuff like dolomite or crushed oyster shell.

[gnathaniel]

Many lithophytes grow on granite rather than on calcareous rocks like limestone. I think the rupicolous laelias (incl. gloedeniana) fall into the former category, and are usually said to be very sensitive to buildup of salts in the medium. Any calcium that does leech out of the coral rock may prove poisonous to your laelia in the long run, though hard water may pose more of a risk since the calcium is already dissolved in it.

If you have a granite countertop place nearby you might be able to pick up some free odds and ends. I'd wager your plant will appreciate that more than coral rock as a substrate.

--Nat

[dbvogt]

Interesting comment, thanks. We had granite countertops installed a month ago when we moved and I could probably beg a piece from the granite company. Failing getting a piece of granite, I could try growing an orchid on the countertop but the wife may have problems with that.

And then there may be a sealer on the granite that would make the top impervious to any element leaching in or out.

All in all a most enjoyable "hobby" although it starts to get complicated. The books say most tap water is fine for orchids but our water is hard. I wouldn't want to grow orchids in plastic chips with distilled water. Just doesn't seem appropriate.

[Island Girl]

Ok, I know this is an old thread, but I wonder if these calcium-loving orchids would like oyster shells? does anyone know?

dbvogt, how has your Laelia glodeniana done since you put it on the coral? I would love to see pics of it! I bet it is really cool looking!