Chlorosis in Trees

When tree leaves are yellow and they’re supposed to be green it’s called chlorosis. Chlorosis is caused by the inability of the tree to absorb the nutrients it needs to form the chlorophyll molecule. Without chlorophyll photosynthesis can’t happen. Without photosynthesis the tree can’t feed itself and will slowly starve to death. Don’t let this happen to your trees.

A Chlorotic Maple

In our area, chlorosis is usually caused by the nature of our soils. More specifically, chlorosis is caused by the chemistry of the clay in our soils. When the clay is formed, the chemical substitution leaves each clay particle with a negative charge. In high pH soils the clay can have multiple negative charges. The nutrient which, when deficient, most commonly causes chlorosis is iron. Now all nutrients must be in ionic form to be absorbed by trees, that is, they must have a charge. Iron ions have a positive charge. The positive charged iron sticks to the negative charged clay like a magnet and is unavailable to the tree.

In trees with iron deficiency, the veins are often greener that the rest of the leaf.

Chlorosis is a difficult problem to treat. When trees are fertilized with most forms of iron, the iron just gets bound to the clay. Our soils are said to have a high buffering capacity, that is, the can absorb a whole lot of positively charged ions without changing the nature of the soil.

This chlorotic tree is dying from starvation.

We at Boulder Tree have spent a lot of time and money researching the causes and treatments for chlorosis. While no treatment always works, we finally found a treatment that we like. We’ve had great success treating chlorosis with a specific, highly chelated, iron product. We apply the treatment in a specific location around the root zone where it is most likely to be absorbed. We’ve treated trees that were near death and brought them back to health with a canopy of deep green leaves. It’s very exciting to save beautiful trees.

Don’t let your trees die from starvation. Give us a call today