Can I fix yellow leaves with fertilizer?

Only if the yellowing is caused by a nutrient deficiency. If the cause is high pH, standard fertilizer will not help.

Will these leaves turn green again?

Usually not. Once a leaf has lost its chlorophyll, it will likely drop, but new growth should be healthy if the cause is corrected.

Northern red oak: yellow leaves, causes and fixes

Check these first

Test the soil pH level.
Check the soil moisture around the base.
Inspect the leaves for green veins.

Likely causes

Iron Chlorosis
Most likely
How to tell: Leaves turn yellow while the veins remain green. This happens when the soil pH is too high, preventing the tree from absorbing iron.
What to do: Test your soil pH and aim for a range of 5.0 to 6.5. Apply chelated iron to the soil around the drip line to help the tree recover.
Poor Drainage
Possible
How to tell: The entire leaf turns a pale yellow and may feel limp. This occurs when roots sit in waterlogged soil for too long.
What to do: Improve soil drainage by adding organic matter or adjusting the grade of the land. Avoid overwatering and ensure the root zone is not constantly soggy.

Yellow leaves on other plants

Find out what's wrong with your northern red oak

The list above covers the usual causes. Pocket Botanist looks at a photo of your actual plant and tells you the likely cause, how serious it is, and what to try first. Identification and a health check are free.

When to worry

If the yellowing spreads rapidly across the entire canopy, it may indicate a systemic health issue. Minor yellowing on older interior leaves during late summer is usually normal.

Stopping it coming back

Maintain proper soil pH and ensure the tree is planted in well draining soil. Avoid compacting the soil around the root zone.

Northern red oak: yellow leaves? Check yours with a photo

Every plant is a little different. Take a photo of your northern red oak and Pocket Botanist tells you which cause is most likely, how serious it is, and what to try first. A few checks a day are free. Save the plant and you get care reminders timed for it.

Get the app · Or check it from a photo now, free

Questions people ask

Can I fix yellow leaves with fertilizer?: Only if the yellowing is caused by a nutrient deficiency. If the cause is high pH, standard fertilizer will not help.
Will these leaves turn green again?: Usually not. Once a leaf has lost its chlorophyll, it will likely drop, but new growth should be healthy if the cause is corrected.

Guides to these causes

Chlorosis

Why are my Northern red oak leaves turning yellow?