Does St. John's wort need full sun?

Yes, it thrives in full sun to partial shade. Too little light will cause the plant to weaken and lose its vibrant color.

Should I cut off the yellow leaves?

Yes, you can snip them off with clean shears. This keeps the plant looking tidy and allows it to focus energy on healthy growth.

St. John's wort: yellow leaves, causes and fixes

Check these first

Move the plant to a brighter location if it is in deep shade.
Check the soil for signs of nutrient depletion.
Look for pests that might be sucking sap from the leaves.

Likely causes

Insufficient Light
Most likely
How to tell: The leaves turn pale or yellow, and the stems look stretched or leggy. The plant is reaching toward the nearest light source.
What to do: Move the plant to a spot with full sun or partial shade. Ensure it gets at least 6 hours of bright light daily.
Nutrient Deficiency
Possible
How to tell: Older leaves turn yellow while the veins remain green, or the whole plant looks stunted. This often happens if the plant has been in the same soil for a long time.
What to do: Apply a balanced liquid fertilizer diluted to half strength once during the growing season. Do not overfeed, as this can burn the roots.

Yellow leaves on other plants

Find out what's wrong with your st. john's wort

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

Yellowing is a concern if it spreads rapidly across the whole plant. It is normal for the very oldest leaves at the bottom to yellow and drop as the plant matures.

Stopping it coming back

Provide consistent, bright light and refresh the soil every year or two. This keeps the plant healthy and prevents nutrient issues.

St. John's wort: yellow leaves? Check yours with a photo

Every plant is a little different. Take a photo of your st. john's wort 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

Does St. John's wort need full sun?: Yes, it thrives in full sun to partial shade. Too little light will cause the plant to weaken and lose its vibrant color.
Should I cut off the yellow leaves?: Yes, you can snip them off with clean shears. This keeps the plant looking tidy and allows it to focus energy on healthy growth.

Why are my St. John's wort leaves turning yellow?