Sure looks like classic iron chlorosis to me; sometimes heavy metal concentrations like copper, zinc, or manganese can produce chlorosis; but if you've got it in 5-1-1 now and are applying chelated iron, you're doing what you can do.
I suppose the possibilty exists of a genetic color variation, as the leaves look healthy... maybe it just needs a little time to adjust.

Looks like magnesium deficiency to me. I would definitely apply a good fertilizer with micronutrients to the soil such as Foliage Pro (water soluble) or Gro Power Professional Citrus Blend fertilizer (granular), and I would also do a foliar micronutrient spray application as well (again). I like Grow More Citrus Growers Blend for foliar micronutrient applications. Doubt this is a genetic variation on the green leaves, John. Looks like classic chlorosis to me. Be sure the tree is getting plenty of sunshine, too. How alkaline is your water in Ontario? If it's very alkaline, you might want to try acidifying your water for a bit, so you can assist in making those micronutrients available to the tree.

Patty S.

Thanks John and Patty.

The tree gets plents of sunshine, and I use rain water most of the time. The PH of my water with foliage pro is about 5.0

I use Foliage Pro most of the time also top dressing with Osmocote Plus with micro nutrients.

My water PH is about 8.0, but very soft, with hardiness about 40. Very easy to acidify.

Thanks
YT

What type of fertilizer are you using Yellow?

Does it have all the trace,minor, and major elements, including what is mentioned above?

What is the pH of your water ing solution every time you water and have you tried using vinegar with your fertilizer if it is a good one?

If there is Iron in your fertilizer and the roots are fine, then I would consider pH an issue.

Mike

Hi Mike,

I have been learning from you guys all the time.

I use Foliage Pro and top dress with Osmocote Plus. My water solution is from 5.0 to 6.0.

This is mysterious.

Thanks
YT

Yellow, that explains it. You are over fertilizing that tree and my adding too much of something else, not sure, you are inhibiting other nutrients from being absorbed.

I would stick with just the FP and use continue to use the water you do if you are certain the pH is ok. My FP does not bring the pH of my watering solution down at all. I have to use vinegar most times.

How often do you fertilize and how much?

Mike

I add some vinegar as well to bring down the pH. I use about 1/4 teaspoon for each gallon of water.

I basically use the same fertilizer pattern for all other plants, they are doing excellent. Except this one. Whatever you do, it stays the same.

Hey Yellow!

I would keep up your regimend God forbid you over due one product over another and kill it.
It could be anything at this point that will straighten itself out over time.
If you have all the right things in check like good sun, stable temps, a good soilless mix if the 5.1.1. with lime, good watering practices, a nice root system and good fertilizer, I can't see why it wouldn't.

I once had a tree that did that no matter what I did and once I upped the vinegar and brought it out of full all day sun, it reverted back to green.

Keeping my fingers crossed for you. All your plants are amazing which is why this one baffles me.

Mike

Yellow, I hope someone comes along has a definite answer for you and tells you.

I feel kind of strange giving you advice since I always considered you a pro at growing the same fragrances I grow in containers with our environments.
You have taught me much over the past with fragrance and it is so good to see you here.

Mike

Hi Mike,

Thanks for all the great advices. You are a pro now.

I guess there is always some plants that we don't understand. Like some little old tree, suffered at young and not responding to whatever you do.

Maybe what I could do is bring it to half a day sun and see what happens.

Thanks
YT

Yellow:

I know how good you are at growing plants as you do and if I were you I would resort to the fact that you are doing all the right things.

Who knows what happened to that plant just 2 months ago when before you bought it, but from the looks of your plants and knowing what I know about how you care for them, there is nothing you are doing wrong.

All your plants are treated as equal and it is bound to respond to your care.

You are using a great mix and fertilizer since it shows in all your other plants.
This citrus may be a tough nut to crack, but it will cave in and respond to your everyday good cultural practices. Please post it when it has filled in green.

You have rechecked your mix composition for that one right?

Mike

I will tell you a story about pH and iron... 15 months ago in Guatemala City we had a black sand "rain" from a volcanic eruption. Turns out that sand is 18 percent iron; and that my friends, is deadly toxic...killed about 300 small Meyers in my nursery before I figured out what to do, as iron toxicity in a nursery is absurd; after almost a whole day of researching I found a similar occurence in Africa; and the solution was to raise the pH so the plant absorbs less iron (note: afte a year it is still killing my roses, but Magnesium sulfate helps). The bottom line is if the soil or water pH is too low, that actually encourages iron absorption. I suspect that this little tree probably picked some heavy metal toxics in the nursery and it will take a little time to clear it out (Mn, Zn, and Cu toxicity manifests as Iron deficiency. Magnesium shortage (sometimes a problem here in volcanic soils) manifests itself in a very clear Christmas tree shape of green on the leaf with the surrounding parts yellow. As Mike said, and I said earlier, you seem to be doing the right things, the plant appears healthy and growing... so have faith and give the litte guy a chance.

I wouldn't use vinegar, as you can kill your plant with that! I started peeing on my lemon that had pale yellow new leaves and they greened up after a week or so. I also added some chelated iron/copper and they seem to be getting better as well.

Not true. Vinegar is perfectly safe at the doses we recommend.
Many, many growers have been acidifying their fertigation and irrigation water for a long time.
Urine, on the other hand, is known to be weak, incomplete, unpredictable, and possibly containing
wastes that are best flushed (such as salts and other stuff, like medication).

Josh

Merciepoo!

Where have you been for the past year? Oops weeks?lol

You and I go way back and you remember what my plants use to look like, I think, right?
Remember when I had yellowing issues, and anything less than vivid green foliage for years with mine, especially, yes, the dreaded ready, your favorite, the evil GARDENIA?!!!lol

I was told by a very well respected grower of a huge well respected citrus company that vinegar, yes, vinegar was the key to greening up my plants for a home hobbyist, and in particular citrus used in proper amounts. He was right!
If the pee method should ever disappoint you, well now you have another option.
I know how much you lOVE green gardenias:-)

Josh: Great explanation to the benefits and uses of vinegar! Thank you:-)

Mike

My pleasure, Mike! I want everyone to enjoy these tips and tricks to keep their plants green.

Josh