Can I save a yellow leaf?

Once a leaf has turned completely yellow, it will not turn green again. It is best to snip it off to help the plant focus energy on healthy growth.

Does yellowing mean I have a disease?

Sometimes, but usually it is a nutrient or water issue. If you see spots or fuzzy growth along with the yellowing, it might be a fungal infection.

Why are my cucumber leaves turning yellow? Causes and fixes

Check these first

Check the soil moisture with your finger.
Inspect the undersides of leaves for pests.
Look for signs of poor drainage around the roots.

Likely causes

Nitrogen Deficiency
Most likely
How to tell: Older leaves at the bottom of the plant turn pale green and then evenly yellow, including the veins.
What to do: Apply a balanced liquid fertilizer or a nitrogen rich organic amendment like fish emulsion. Follow the package instructions to apply every 2 weeks during the growing season.
Overwatering
Most likely
How to tell: The soil stays soggy and the yellowing starts on the lower leaves, often accompanied by a mushy stem base.
What to do: Let the top inch of soil dry out before watering again. Ensure your garden bed or container has excellent drainage to prevent water from pooling.

Yellow leaves on other plants

Find out what's wrong with your cucumber

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 very oldest, lowest leaves to yellow and drop as the plant matures. Worry if the yellowing spreads rapidly to new growth.

Stopping it coming back

Maintain consistent soil moisture and feed your plants regularly with a balanced fertilizer throughout the summer.

Cucumber: yellow leaves? Check yours with a photo

Every plant is a little different. Take a photo of your cucumber 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 save a yellow leaf?: Once a leaf has turned completely yellow, it will not turn green again. It is best to snip it off to help the plant focus energy on healthy growth.
Does yellowing mean I have a disease?: Sometimes, but usually it is a nutrient or water issue. If you see spots or fuzzy growth along with the yellowing, it might be a fungal infection.

Why are my cucumber leaves turning yellow?