Follow up question on Cal/Mag deficency

[Rhonda Svoboda]

Several of my Orchids have splotchy leaves. I posted about this a few months ago. I tried an organic lime mix and it didn't help.
I just tried a straight cal/mag supplement that I hope helps. My question is: how often should I use it? I use Better Grow orchid food and it does contain 1% mag but no cal.
Also- will the existing leaves always look splotchy or will they return to normal? In other words- how will I know its working?
Are there better orchid fertalizer's that I should try?
Thanks

[Shadeflower]

Hi Rhonda, I had to go back to see what post you were referring to, I am guessing it was the splotchy leaves and I think you were spot on that that was caused by your lighting. LED lights do create that bleached look you had if they are too close, it looks completely different to a sunburn so not many people know what to look for.
As such it was mis-diagnosed as a Cal-Mag deficiency which it rarely is, a Cal-Mag toxicity is usually more likely!
So you added more Cal-Mag and big surprise that will have not solved anything but possibly made things worse.
As to your question whether a leaf ever recovers from damage - no not really. If it turns a bit purple or red from too much light then that can fade again but any damage to the leaf is permanent.

The way to tell if it is a deficiency or led light damage is generally quite straightforward, deficiencies form on the lowest leaves first and light damage forms on the leaves closest to the light. That is the best way to tell them apart.

As to whether you need any Cal-Mag or not feels like something that has been anwered many times but the simple version is that tap water contains enough calcium if not slightly too much. Rain water or RO water contains too little Calcium.

So if you use tap water your fertilizer should contain no additional Ca or Mg

If you use Rain or RO water then your fertilizer needs additional Ca in the same quantity as the Nitrogen (N) it contains and half the magnesium

So one aims for 1 N - 1 Ca - 0.5 Mg

There are 16 other Nutrients that a ferilizer should have but those numbers are forulated by the scientists and not for the home user to worry about, what we need to worry about is our N to Ca and Mg ratio which will vary depending on whether we use tap water, rain water or RO water so needs to be adjusted based on which we use.

[Rhonda Svoboda]

Yeah- I don't think its from the lights. It is definetly a cal/mag deficency. I am not going to go into all the details as to why.

[Shadeflower]

Ah ok that makes me feel better Rhonda, I knew you dislikes my advice I just thought you disliked me for some reason cause I knew you ignore me I just didn't know why.

I certianly have not given you any bad advice, my advice does differ from some of the experts advice but as you probably know I disagree with alot of old orchid myths and wives tales on how to do things including keeping certina orchids dry in winter to encourage blooming.
Some believe in it, others do fine blooming theirs without a dry period. I wouldn;t go so far as to say either are wrong, that is quite rude but if that is how you want to grow your orchids, that is fine by me, drown em in Cal -Mag for all I care.

It is ironic that you should mention advice that will harm your orchids, you seem to blndly tust someone else over me based on what? That I am wrong you know better or because the person I was disagreeing with told you in confidence not to lsten to me because I was wrong?

Think about it. I know who told you I was wrong.

[SouthPark]

I had to do a search on what the previous post was - and assume that this thread follows on from this one here ---- (click here).

Shade's post does have some good points - which weren't recommendations ----- but considerations or observations that we could make - in order to narrow down the possibility or possibilities behind the developed yellow regions on the leaves.

Consider the age of the leaf (leaves) ----- are they the newest ones? And the position - location of the leaves. Any hidden new leaves that are shaded a bit (under another leaf) that isn't patchy? Or any leaves that are completely fine? And is it occurring for just a single plant only, while all the other orchids don't have the patches?

Also - for this pic here ---- (link) ----- does the yellow patching extend into the vertical region of the leaf (that we can't see in that picture)?

Also - the period of time that the patchiness has been there for. If the orchid has been growing just fine under the same lighting conditions for ages, and then it abruptly gets yellow patches on various leaves ------ then that's another aspect to think about.

[Shadeflower]

Thank you South Park,
helping out on this forum is exhausting, instead of appreciation all i get is questioned and even accused I have a secret agenda to hurt other people's orchids?

No thank you, that is not what I signed up to.

If you had listend to my advice several motnhs ago Rhonda you would not be in this position today but instead you rather believes I wanted to harm your orchids.

I thought sttealing a garden gnome was bad but geez why would I come on here to purposefully give out bad advice? Quite some accusation to be honest.

But seeing as I suspect who instigated it I am more mad at that person so I'm done for a bit. That is what they wanted. Clearly I have been too active on the forum lately which I was enjoying but someone always comes along to spoil the fun.

[Rhonda Svoboda]

Ok.
This has grown a life of its own. First Shadeflower, I did not intend on offending you. Sometimes words come accross via text differently than intended. Having re-read what I wrote I want to apologize for that.
Second, we're all learning here and hopefully growing in our orchid knowledge as we help each other out.

[Leafmite]

I actually lost many nice orchids, mainly nearly every Cattleya, to Calcium deficiency many years ago so now I am very careful about avoiding Calcium deficiency (probably overboard).

Use the Cal-mag supplement every time you water during the summer. Rain will wash it out of the medium and you need a steady supply. If you are getting heavy rains for a week and your plants are in the open, run out between rains and give them a dose of Calcium.

I use powdered milk in the summer and usually add a little to the watering can every time I water. When we are getting heavy rains, I just sprinkle the powdered milk on the orchid medium.

During the winter, if the Catteyas are not growing, I only add it once a month or less. I do keep eggshells in the pots for a very slow, steady Calcium additive (in my lava rock, it takes about three months before they begin to decompose and release Calcium so this is not an immediate solution).

Hope this helps!

---------- Post added at 08:56 PM ---------- Previous post was at 08:23 PM ----------

The problem with giving/taking advice from an online forum is that we all live in different climates and have different issues. Some grow in greenhouses and basements which are very different from growing in the window or even the window under lights. It is not the fault of the person giving advice if it doesn't work, it is just that this works for them because it is their climate, their method of growing...even their water quality. It is helpful if, when giving advice, people do remind others how they are growing their orchids and their climate. Some don't realize how much of a difference this makes.

When I first joined online forums, I didn't realize that most of the revered professionals of the forums giving advice were growing in greenhouses and I followed this advice as I wanted my orchids to do even better (up til then, I had never lost an orchid)...that did not go at all well.
I always try to remind people form different areas that I grow in Ohio and that my climate can be very rainy during the summer (sometimes cold and miserable) and cold/dry during the winter. I grow mostly Cattleyas. That accounts for the adoration of lava rock, basket pots and calcium. If we have a hot and dry summer, I can water the rock every day and that helps with the humidity for the orchid. If we have a cool, wet summer, I just add lots of extra Calcium. Either way, the rock works for me. But...it might not work for others in different climates.

I belong to an orchid society now (found one ten years ago) and that has been wonderful. We are all growing here in the same general climate and, yeah, it is really great to be growing orchids together with others dealing with the same exact issues...Ohio issues.

[Rhonda Svoboda]

Thank you!! I appreciate your input.

[Ray]

If you want to confirm that the splotchiness is a deficiency (more likely magnesium than calcium), water with a 1 tablespoon-per-gallon solution a time or two.