Yellow pin oak leaves with green veins in St. Louis
Yellow leaves with green veins can suggest chlorosis, but they do not tell you which product to apply. Start with the tree, root conditions and a soil test.
Updated November 2, 2026
What might be happening?
Missouri Botanical Garden describes this leaf pattern on pin oak and explains that iron may be present in the soil but unavailable to the roots. Root damage and moisture extremes can also cause yellowing; the Garden advises diagnosis before assuming an iron shortage.[9]
What to tell the arborist
Tell us whether the newest leaves changed first, whether the problem returns each year, and whether the root area stays wet. Mention lime, fertilizer or other products already used.
The next step
Ask for an arborist visit and soil-pH assessment. The plan should address the reason nutrients are unavailable and the condition of the roots, rather than treating yellow leaves as an automatic need for more fertilizer.
What not to assume
A treatment may change the appearance without correcting the underlying soil problem. Do not add iron or change soil pH without a diagnosis and a property-specific recommendation.[9]
This is general guidance, not a diagnosis. Your arborist confirms the cause and treatment suitability on site; some concerns also need laboratory confirmation.
Immediate danger from a tree or hanging limb? See 24/7 storm help. Stay away from downed lines and anything touching them; call the utility for electrical hazards and 911 for injuries.