Light green/dark green splothes?

[greenpassion]

Originally Posted by Orchid Whisperer

Plain Epsom salts from the pharmacy for Mg and S, and gypsum (or plaster of Paris) for Ca and S. Teaspoon each per gallon. Add about a cup or two of this to your regular water. WAY cheaper than buying CalMag. But, if you don't mind spending the $$, there is no problem with the pre-made CalMag products. Any should be fine.

Ok, but I'm not clear on how much. I make up gallon jugs of water with MSU. Should I add a teaspoon of Epsom salt to this? When you said to add a cup or two at each watering, am I to understand that I add a cup of Epsom salt to the gallon jug? That sounds like an awful lot...and do I give them the MSU and Epsom mix at every watering? Please forgive my obtuseness here

[estación seca]

Originally Posted by greenpassion

Ok, but I'm not clear on how much. I make up gallon jugs of water with MSU. Should I add a teaspoon of Epsom salt to this? When you said to add a cup or two at each watering, am I to understand that I add a cup of Epsom salt to the gallon jug? That sounds like an awful lot...and do I give them the MSU and Epsom mix at every watering? Please forgive my obtuseness here

Most agronomists recommend not mixing calcium nor magnesium with other plant nutrients. Depending on the pH of the water there may be solubility issues, and the calcium may precipitate out of solution. Orchid fertilizer is usually applied at a very low dilution, so this is probably less likely for us.

Also, there is a limit to salt tolerance in water for orchids. Fertilizer consists of various salts. Most people use nitrogen fertilizer and calcium-magnesium fertilizer at different waterings.

[Orchid Whisperer]

A cup of the solution (you made with the Epsom salts and gypsum) to a gallon of whatever you use to water your plants when not fertilizing. If you are fertilizing really dilute fertilizer, each watering, you can add the solution to that. In my post I did not indicate that this is needed every watering. I usually do at least weekly in summer.

The information about not adding sulfates (like Epsom salts and gypsum) to your fertilizer is correct, to a point. My understanding is this can re-precipitate sulfates, often gypsum. I think it is mostly true for higher concentration stock solutions.

[greenpassion]

Oh No! I hadn't read the last post to my question. So I have been using my pre mixed gallon jugs with 1/2 tsp MSU fertilizer and I have been adding 1/2 tap cal mag to the mix! I've been watering with this each time. Is this way too much??

[Dollythehun]

I made the same mistake, greenpassion. Everyone survived. But, I learned something, as did you. Healthier plants are on our horizon.

[greenpassion]

Thank you Dolly. So I should cut the MSU feet. In half and also use less cal mag if I'm going to feed at every watering?

---------- Post added at 05:18 PM ---------- Previous post was at 04:50 PM ----------

That was supposed to say "cut the MSU in half, not feet!!

[Dollythehun]

I understand too well voice to text. I feed both but individually (now) at quarter strength and once a month, or when I think of it, I flush with clear water. Please don't over think this. Most orchids are forgiving. I've made most every mistake with mine.

[greenpassion]

Ok. I'll peel myself off the ceiling now Thank you!

[Dollythehun]

Honestly, I bumbled around for years without the OB. My plants survived. I never killed one.The only two I've killed were rescues that I couldn't. After you peel your self off the ceiling, have a glass of your favorite wine...

[greenpassion]