Gypsum as calcium source for peat loving plants

[partisangardener]

I read somewhere that gypsum is a possible source of calcium and sulfur. Especially for plants loving more acidic soils.
Some orchids and carnivorous plants seem to have sometimes problems.
It did not happen yet to mine but nobody knows.

Is there something to it?
'Would it affect the PH too much, or is it more neutral as I was told.

Some others say that it is negligible.

[ArnoldT]

I use gypsum as part of a COF Complete Organic  Fertilizer on my community garden beds.

It's has sulfur which is important for plant growth.

[partisangardener]

When sulfur gets free calcium should be then available to plants. Every plant needs calcium and this is in ordinary soil not too sparse, but in peat very rare.
Or is my understanding of this matter too patchy.

[Jeffnz]

Gypsum provides two of the secondary plant macronutrients, calcium and sulphur. Unlike limestone, it generally does not affect soil pH.

[brianw]

My understanding is Calcium is added to acid soils purely to raise the pH and help nutrient takeup. Which I have no idea. As I grow on chalk not a problem I come across too often outside pots.

[partisangardener]

It is an  essential plant nutrient for cell membrane etc.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4243668/

[brianw]

When I watched my house foundations being poured onto clean white chalk, and a 12th century church just up the road is built with "clunch" blocks and flints, and any digging in the garden results in me often throwing chunks into the hedge; it is difficult to think of actually adding it to anything I grow in. Tap water here is similarly "hard". 99% of the water I use in my greenhouse is collected rain water (and pots in the garden when I have enough) so maybe I should think about Ca levels sometimes, although I use bonemeal a lot so never short of Ca.

[Jeffnz]

Gypsum, or calcium sulphate (CaSO4), is a naturally occurring mineral. It provides the essential nutrients calcium and sulphur but does not affect soil pH; it is neutral (pH is ~6.7). When gypsum dissolver it gives a solution of Ca and SO4 ions, the ions can then be taken up by roots.