Why Are My Leaves Yellow?

While you expect leaves to change colors in the fall, a tree with yellow leaves in the summer may indicate a health problem known as chlorosis. Trees most commonly impacted by chlorosis include white oak, red maple, pin oak, river birch and white pine. Chlorosis does affect the overall health of your tree, and is considered an abiotic tree disorder, as it is caused by a non-living thing. Have your tree evaluated if you are seeing yellow leaves.

chlorosis in red oak leaves
Tree treated for chlorosis

What is chlorosis?

The visible sign of yellow leaves is the result of limited chlorophyll formation. Deficiencies of minerals–iron (most common), zinc, magnesium, and/or copper are the cause of chlorosis. Although the soil may not be lacking in these minerals, there are several factors that contribute chlorosis:

  • Very wet weather
  • Poor drainage
  • Heavy, compacted soil
  • Alkaline soil, making it more difficult for your tree to absorb certain minerals

Will chlorosis hurt my tree?

Chlorosis can get worse through the season, and in severe cases will cause the leaves to turn brown and drop early. In addition to this, chlorosis causes stress to the overall health of the tree. Therefore, the tree is more susceptible to further disease and pest attacks. Long term, chlorosis can limit the life expectancy of a tree if impacted over several seasons.

How is chlorosis treated?

First, it is important to have an ISA Certified Arborist complete a full evaluation of all environmental conditions to accurately diagnose all stress factors and prescribe care based on specific circumstances for your tree. This prescriptive care could include mineral applications to the soil or foliage and adding organic matter to the base of the tree. Finally, treating your tree is recommended to help your tree stay healthy and meet its full potential!

Read more about Chlorosis: Chlorosis Fact Sheet

Contact Rainbow Treecare to bring the green back to your tree!

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