Cal mag/Epsom salt

[Chicago]

I have been reading some posts mentioning calcium and magnesium supplementation when growing Cattleya alliance. How do you do it? Folks mentioning Epsom salts...how do you actually implement them? Thanks!

[Ray]

First and foremost, determine if you even need to supplement them. There really IS such as thing as "too much of a good thing". Don't arbitrarily start adding stuff until you know you need it.

If you're on public water, your utility should be able to give you an idea of the hardness. Hard water likely means you need not add more calcium. If they can also tell you the magnesium content, that's be your guide, as well.

If you need both, a cal-mag supplement to your normal fertilizing regime will work, as will the use of a fertilizer that provides both elements.

Epsom Salts is a great magnesium additive to your irrigation, if that's all you need.

[Chicago]

Thank you! If there is a need for mag, do you just sprinkle some Epsom salts on the substrate? Or desolve a teaspoon in a gallon of water? Any recipes or recommended products?

[thefish1337]

Originally Posted by Chicago

Thank you! If there is a need for mag, do you just sprinkle some Epsom salts on the substrate? Or desolve a teaspoon in a gallon of water? Any recipes or recommended products?

easy to get a product like dynagro/MSU/klite that has calcium and magnesium in balance with other nutrients imo. if you want to add them in yourself you can add calcium nitrate and epsom salts :

taken from: https://staugorchidsociety.org/PDF/C...ySueBottom.pdf

1/4 tsp calcium nitrate per gallon is 69 ppm calciumm and 58 ppm nitrogen

1/4 tsp epsom salts is 34 ppm magnesium and 44 ppm sulfate

check your tap water quality analysis and see if you need to supplement calcium or add less if your tap water contains lots of calcium.

[sskmaestro]

Originally Posted by Chicago

Thank you! If there is a need for mag, do you just sprinkle some Epsom salts on the substrate? Or desolve a teaspoon in a gallon of water? Any recipes or recommended products?

Excessive salts in raw form can burn the orchid roots upon direct contact. We always prefer dissolving the epsom salt in water and giving the roots a soak.

[Herrania]

What I prefer is adding chunks of shell or marble, and dolomite to the potting mix. Dolomite is defined as being 50% calcium carbonate 50% magnesium carbonate, and is favored as a building material because it weathers slowly. So it slowly provides mineral, but is the least likely to burn the roots.

[Ray]

For me, the trouble with such solid additives is that you really have no idea how much of the minerals your plants are getting. Sure, they break down slowly, but what does "slowly" mean?

[Orchid Whisperer]

You will find that 1/4 tsp each of calcium nitrate and Epsom salts per gallon won't burn roots, and also also shouldn't cause any precipitated in there medium. In winter, I actually go closer to putting that quantity into 2 gallons.

Much less expensive than pre-mixed Cal-Mag products.

Plants that are actively growing will benefit the most from this supplemental Ca and Mg.