Quote Originally Posted by Jef09071984 View Post
Just put pebbles in the saucer so that your pot is not sitting in the water. I think Prags is the wild same with the other lady slipper orchids usually grow abundantly in limestone. So i suggest put some limestone in your potting mix.
The limestone they grow in is often ( not invariably) the sort called Karst wjich is amazingly hard like marble or glass even - it is so slowly soluble that it can't contribute much in the way of minerals to the plants ; It is only a small group of paph species which grow thus - in fact they are called "the limestone paphs" - and are bellatulum, niveum, concolor, godefroyae - there might be another which does not come to mind at the moment. Some paph growers, including myself at one time, used to put a spoonful of dolomitic lime ( which is a limestone/magnesium mix) on top of the compost, periodically, and wash it in.
Then - speaking for myself, I went on an expedition to see them growing in the wild, and collected samples of the humus in the cracks in the rock in which P.bellatulum grew, and tested it ; I found the humus was in fact slightly acidic ( pH 6.0) and consequently putting lime on the compost would not help, only hinder. I also found P.concolor growing in a sort of sand, at the edge of an exposed mass of a hard non-limestone rock , and that had a similar pH, even higher in places ( 5.5) .
I have also seen where one sub-species of niveum grows ( P.Ang-thong) and that is a hard white limestone cliff - Ang-Thong one of a set of islands a 4 hour speed-boat trip from a place I was staying in the Gulf of Thailand, once - but I didn't get to collect any humus there , and the only plants I saw had been collected by the Reserve wardens, and potted in sand from the beach - and they didn't look very happy..

BTW Most UK Phrag growers who use saucers of water to stand the plants in, only do that in the summer - but then we have a cold winter .