Chlorosis: yellow leaves means major issues

This picture shows the start of Iron Chlorosis on a silver maple. As the problem worsens the area between the veins will get a lighter shade of yellow.

Out here on the prairie we can run into a lot of different issues with our trees. One of the most common for a certain group of trees is interveinal chlorosis, also called iron chlorosis. In the Sioux Falls area and over most of the northern great plains, it effects mostly maple and birch, but can also be found in other species not usually found growing in the wild on the prairie.

Explaining the cause can get a bit complicated with all the chemistry involved, but basically, because of the higher pH of prairie soils (above 7 (neutral)) iron is gobbled up by the soil and not as easy for the trees to uptake and use to make chlorophyll.

Chlorophyll is what allows the tree to photosynthesize (make food) and gives the leaves their green color. Less iron means less chlorophyll, which means the tree has a lowered ability to produce food for itself.

This is a problem for the trees over time. The trees often end up with less stored energy for defense from insects, disease, or decay and also have less energy to grow a stronger and bigger root system. Without the stronger root system, the trees have even a lesser ability to uptake iron, so the chlorosis gets worse and worse.

Fixing the issue isn’t as easy as adding iron or acid to the soil either. Most prairie soils have what is called a high buffering capacity. Its the soils resistance to change in pH. So with that, you can dump all the iron and acid into the soil you want the soil will still gobble up all the iron and not change its pH.

To correct the problem effectively, certain landscape and care changes along with some help from the right chemicals can reverse the chlorosis and help make the tree string enough to battle the problem on its own.

Contact Aspen today to learn about our chlorosis care program and how we can make your tree healthy again with a long term plan for its success and health. 218.289.4862 or sam@aspenarbo.com