Mystery Leaf Damage

[sadie]

I have a couple of phals which have some really odd leaf damage. I've noticed it just in the last couple of weeks--a month at most. Before that, they were green and thriving. My first thought was spider mites--but there's no tell-tale redness when I wipe my finger on the underside of the leaves. I'd guess lack of water, but the leaves are still rigid, not at all floppy. As you can see, the leaves are getting increasingly yellow but not in a way that makes me think they are getting burned.

I have already sprayed all my orchids this week with insecticide/miticide just in case, but I am worried that isn't the problem. It has me worried because the first plant with these symptoms has already lost a bottom leaf--yellowed and dropped off.

Any suggestions?

[Becky15349]

This happens to me too - and I've love to know why. Sometimes, its easy to see that the older growth is perhaps being disposed of, and that makes sense - sometimes they shed their much older leaves as they are growing new ones...but if the leaf isn't that old, I'd say it has to be the roots. Too much water maybe? Most of my plants in my life turn yellow when they are overwatered- -that's just my 2 cents You may also have a virus, if you notice that this is happening to more than one plant all of a sudden...I'll let the experts give their opinions.

[clintdawley]

Chlorosis like that is usually indicative of too much light. The new leaves aren't that affected because they have been grown in the higher light levels--it's the old growth that hasn't adapted that is affected. I've seen this happen on my catts--the old p-bulbs yellow why the new ones are happy as clams.

Maybe some shading and nice dose of Epsom Salts (Magnesium) would help out.

[jeffjohnson23]

I had a simalar problem. My Phals bottom leaves turned yellow within a week and fell off. A few days later, I moved my Phals and the good green leaves fell off. Crown rott was the cause of my problem.

[Lizgeo]

I am having the same problem here. Can I get epsom salt from box store, or do I have to mail order it?

[Brutal_Dreamer]

I am having the same problem here. Can I get epsom salt from box store, or do I have to mail order it?

You can get it at a grocery store most likely, but any store that has plant supplies will carry it. It is used for several different purposes. Be sure to check in the pharmacy area too if you don't see it on the shelf in the main store.


Regarding the leaves: I agree with Clint's assessment. It could be due to the new GH, Sadie. They are getting better light and are having to adjust. I don't know if you will be able to cure it with the Magnesium, but I don't think it would hurt to try.

Cheers,
BD

[cherublace]

what's the deal with the magnesium? how do you use it? how much? what's the idea behind it? thanks.

[Brutal_Dreamer]

what's the deal with the magnesium? how do you use it? how much? what's the idea behind it? thanks.

Magnesium helps form chlorophyll in plants and is essential for photosynthesis. It is usually found as a component in fertilizers, just in very low amounts. In this case, adding some magnesium to her water for these phals may help the leaves better process the brighter light levels.

Cheers,
BD

[clintdawley]

You can buy Epsom salts at any drugstore. Just the stuff of the shelf works fine. I would recommend 1 tsp per gallon in preferably very soft water.

Magnesium aids in chlorophyll production, which can aid plants that show light related stress.

what's the deal with the magnesium? how do you use it? how much? what's the idea behind it? thanks.

[sadie]

Thanks Bruce and Clint--I think you are probably right. The plants showing the most of this yellowing effect do tend to get the most sunlight. I think I'll up the shade cloth and I will definitely pick up some Epsom salts.

So 1tsp per gallon? Should I start weaker than that and see what happens--like 1/2 tsp per gallon?

Just when I thought I had this orchid thing figured out, I go and completely change my growing environment! So, now I feel like I have to start from scratch in some ways. Thanks again.

Clint--it seems you and I have opposite problems. Your vanda needs more light, my phals a little less.