A Gardeners Forum Forums General Discussion The Plants and Flowers Forum Calamondin Orange Tree

I have had two calamondin orange trees for 45 years and they are loaded with oranges now. However, one of the trees has abnormally very light green leaves. I don't know what is wrong. Any ideas?

Welcome, Terry!
The difference in the leaf color probably has much to do with feeding. Maybe iron, phos or something levels in the soil.
I found this:
In general you should be doing your citrus fertilizing about once every 1 – 2 months during active growth (spring & summer) and once every 2 – 3 months during the trees’ more dormant periods (fall & winter).

To find the best citrus fertilizing timeframes for your tree, judge based on the tree’s physical appearance and growth. A tree that looks lush and dark green and is holding onto fruit does not need to be fertilized as often. Fertilizing too much when the tree has a healthy appearance may actually cause it to produce inferior fruit.

Citrus trees are most nutrient hungry from the time they bloom until they have firmly set fruit so make sure you apply citrus fertilizer when the tree is in bloom regardless of health so that it has enough nutrients to properly produce fruit.
All citrus trees will benefit from a heavy nitrogen fertilizer that has some phosphorous in it. Citrus trees also like to have somewhat acidic soil, so an acidic fertilizer will also be beneficial in citrus tree fertilizing. The easiest citrus fertilizer to use is the kind made specifically for citrus trees.

Hi Terry, I think the above advice is good, and also, light coloured leaves on citrus can mean that they need some magnesium sulfate, which (you probably already know) can be bought as 'epsom salts'.