Chlorosis

[Fuerte Rav]

Hi
In the last couple of days I've noticed leaves on my 2 Mandarin trees are showing signs of chlorosis (the orange and lime trees look fine). Also the leaves on my Thunbergia Grandiflora (pics below).
I think I've diagnosed it correctly and I've bought and applied an iron supplement sold for this purpose.
What I can't find is an answer to the following:
Do the affected leaves recover, ie turn nice and green again or will I just be watching for new healthy looking leaves?
Alternatively is there any other likely culprit that could be causing this?
TIA

[Dollythehun]

I think you nailed it. If memory serves me, they will turn green again. In the nursery, had to use an iron supplement because of our water. Lord, that's been many years and a career ago.

[Fuerte Rav]

Thanks Dolly.
Be interesting to see progress (hopefully!)
I've also treated all my other citrus trees because they are all in the same media and get the same watering/feed etc.
Looking this evening my hibiscuses and bougainvilleas are also showing signs..... Looks like I need to treat the whole garden perhaps?
Do you know what other plants are susceptible to this?

[Dollythehun]

No, Ray may know. My problem was the petunia family. But, I also have some trouble with my Rhodies up by the house. We have pure sand, hard water and a slope. Last year I used an iron supplement around their base and it did green them up.

When you're in the business, it's often hard to buy a small quantity of anything. I still have most of a 50# bag of ActinoIron. I'd offer you some but, shipping across the world is prohibitive. Lol

[Fuerte Rav]

Originally Posted by Dollythehun

I still have most of a 50# bag of ActinoIron. I'd offer you some but, shipping across the world is prohibitive. Lol

[Ray]

I don't know for sure, but deficiencies in Fe, Mg, or even N might be involved. The first thing I'd try would be a foliar urea spray.

Yes, I would expect the leaves to green up again.

[DirtyCoconuts]

Foliar urea spray sounds like the dog peeing on them lol

[estación seca]

Iron or magnesium deficiency lead to chlorosis. Nitrogen deficiency leads to uniform yellowing. Yes, the leaves will likely green up. Water pH has a lot to do with mineral absorption.

[Dollythehun]

When I took Master Gardening, I was taught that the ph and composition of your soil greatly contributes to mineral uptake, as well as your water.

In our case, we have pure sand, almost beach sand. Sand particles are the basketballs of soil (silt being golf balls, clay representing softballs.) So, since the space between particles is so large, water flushes out nutrients easily; add to that our raised beds. This is why you water sandy soil more frequently and for less duration. So, it follows that the soil might be deficit for some plants more than others.

Our method has been to collect shredded leaves and mulch heavily with them every spring. Then, (since I bought in quantity) I throw time release down after I mulch. I still have to water often.

This is a very inelegant way of explaining but, this is what the state of Indiana taught me.

[Fuerte Rav]

Thanks for all the replies.

Urea foliar spray - DC you made me laugh, I had been thinking of training my (girl) dog to use a potty so I could collect it after I read Ray's suggestion ......
But, some of you may remember that I have mentioned our sewage system before (don't read this if you are eating!), basically everything from the house goes into a tank and ends up irrigating our garden. Today I attached the hose to the pump and did a foliar spray of all the affected plants. I chose the day carefully, virtually no wind for a change, total cloud cover (no rain as is normal), and pretty cool for us, 18C. I had already given the iron supplement to the Mandarins and the Thunbergia Grandiflora - now it's wait and see.