Should I cut off the yellow leaves?

Yes, you can snip them off with clean shears. This keeps the plant looking tidy and prevents potential fungal issues.

Can too much sun cause yellowing?

Yes, if the plant gets too much direct afternoon sun in a hot climate, the leaves can bleach and turn a pale yellow. Move the plant to a spot with afternoon shade.

Smooth Hydrangea: yellow leaves, causes and fixes

Check these first

Check the soil moisture by sticking your finger an inch deep.
Inspect the drainage of your pot or garden site.
Look for signs of pests like aphids on the undersides of leaves.

Likely causes

Overwatering
Most likely
How to tell: The leaves turn yellow starting from the bottom of the plant and feel soft or mushy. The soil often stays soggy for days after watering.
What to do: Let the top 2 inches of soil dry out completely before adding more water. Ensure your pot has drainage holes or that your garden bed is not sitting in a low spot that collects water.
Nutrient Deficiency
Possible
How to tell: Leaves turn yellow while the veins remain green, often indicating an iron or nitrogen shortage. This happens most often in very alkaline soil.
What to do: Apply a balanced fertilizer formulated for acid loving plants in early spring. If the soil pH is too high, add elemental sulfur to help the plant absorb nutrients better.

Yellow leaves on other plants

Find out what's wrong with your smooth hydrangea

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

It is normal for the oldest leaves at the base to yellow and drop as the plant prepares for winter. Worry if the yellowing spreads rapidly to new growth during the peak of summer.

Stopping it coming back

Maintain a consistent watering schedule and mulch around the base to keep soil moisture stable.

Smooth Hydrangea: yellow leaves? Check yours with a photo

Every plant is a little different. Take a photo of your smooth hydrangea 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

Should I cut off the yellow leaves?: Yes, you can snip them off with clean shears. This keeps the plant looking tidy and prevents potential fungal issues.
Can too much sun cause yellowing?: Yes, if the plant gets too much direct afternoon sun in a hot climate, the leaves can bleach and turn a pale yellow. Move the plant to a spot with afternoon shade.

Why are my smooth hydrangea leaves turning yellow?