calcium mxing directions

[orchidsarefun]

I use oyster shell "pebbles". I sprinkle a few at the bottom of my 2gallon watering can and these take about 4-5 months to dissolve in the course of watering. I then throw a couple more in.....and so on. Its easy to know when to refill as I don't hear the rattling of the pebbles when the can is empty. Works for me !

[PaphMadMan]

Originally Posted by dickjo

What would you recomend in a non commercial application

Caclium nitrate is used in commercial horticulture when a caclium deficiency is seen by symptoms or found by chemcial analysis. Its a good fix when you need to save your crop that may have only a few weeks to months to reach maturity. But needing it is a sign that your long term fertlizer plan is lacking.

It can also be used as part of a commercial hydroponic system as part of a planned fertilizer rotation.

For a private orchid collection where you're looking for long term health of plants, you're better off with a complete water soluble fertlizer including calcium, magnesium, sulfur and micronutrients, as others have mentioned. It is effective and so much easier to do consistently than trying to figure out how to balance this fertlilizer and that supplement, this and that, when and how.

Personally, if I had access to good rich home-made compost I'd never use a commercial fertlizer at all for orchids except for miniatures. Compost may be low in calcium and magnesium, so limestone-loving orchids would get some dolomite limestone grit mixed into the media (has calcium and magnesium), and the ones that don't like limestone might get magnesium sulfate (epsom salts) a couple times in spring.

[rick84]

Well said PaphMadMan.