Hello.

Some of the leaves on my elms are starting to change color to white.

What is the problem?

Thanks in advance.

Matte, please take a look and see if it helps:

If the plant is inside then that is a problem, if it is outside then I would cut them off and and see if happens again.

Clicio, I know the guide says simple. But can you explain it to a amateur? It looks interesting.

The tree is outside.

Matte, it is self explaining.
Plants need micronutrients, specially in pots. So we have to fertilize AND give them the micronutrients they need, from time to time.
Chlorosis is the most common (lack of iron mostly).
Carbon Dioxide (pollution) can turn leaves whitish.
I don't know if your problem is simply the Elm being a variegated cultivar, or if it is really a deficiency problem.
Do what Geoff suggested, cut off the white leaves and wait to see if it happens again.

Now i understand the guide, very useful. Thank you!

The tree has been feed with bio gold fertilizer, so I think don't think it needs nutrients?
I will cut them off. Thank you.

Research also for PH inbalance : )
Sometimes they cannot get the micronuts, even if it’s present..

Felidae I think you are right. I have a couple of questions that I hope you will answer

The water I use contains a lot of calcium. I have read that it affects the pH value. Perhaps it may be the reason why the tree is unhappy?

What can I do to get the right pH value in the soil, if I have a lot of calcium in the water?
Thanks in advance!

Seaweed extract with sequestered iron.will help, but I don't think that is the "problem" I think there is nothing wrong with the leaves, if it was mine I would not be concerned at all and would just cut them off and see if they return. The leaf is showing a lack of chlorophyll but iI don't see it as a problem.

One question how many leaves are showing this? We can only see a few in the picture.