Skip to content
Pocket Botanist
Get the app

Black poplar · Populus nigra

Why are my black poplar leaves turning yellow?

It is less common for a healthy black poplar to have yellow leaves, so this usually points to a fungal issue like poplar rust or a watering imbalance. Check the underside of your leaves for small orange or yellow spots first.

Not sure it's this? Check a photo of your plant for free

yellow leaves on a plant
Photo: Trio3D, CC BY-SA 4.0

Check these first

  1. Inspect the undersides of leaves for orange or yellow spots.
  2. Check the soil moisture level by sticking your finger 2 inches deep.
  3. Look for signs of standing water around the base of the tree.

Likely causes

  1. Poplar rust

    Possible

    How to tell: You will see small, bright yellow or orange pustules on the undersides of the leaves. These spots eventually turn brown as the fungus matures.

    What to do: Remove and destroy any infected leaves to stop the spread. Apply a copper based fungicide if the infection is widespread, following the label instructions for application frequency.

  2. Overwatering

    Possible

    How to tell: The leaves turn yellow and may feel soft or mushy. The soil stays wet for more than 14 days.

    What to do: Allow the top 2 inches of soil to dry out before watering again. Ensure your planting site has good drainage to prevent water from pooling around the roots.

Yellow leaves on other plants

Find out what's wrong with your black poplar

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.

Download on the App StoreGet it on Google Play

When to worry

If the yellowing spreads rapidly across the entire canopy, it could indicate a severe fungal infection that requires treatment. A few yellow leaves near the base in late summer is often just natural aging.

Stopping it coming back

Keep the area around the base of the tree clear of fallen leaves to reduce fungal spores. Ensure the tree gets full sun to keep the foliage dry.

Black poplar: yellow leaves? Check yours with a photo

Every plant is a little different. Take a photo of your black poplar 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.

Download on the App StoreGet it on Google Play

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

Questions people ask

Can I save leaves that have yellow spots?
Unfortunately, leaves with active rust spots will not turn green again. It is best to remove them to protect the rest of the tree.
Does my poplar need fertilizer if the leaves are yellow?
Not necessarily. Yellow leaves are rarely caused by a nutrient deficiency in established poplars, so check for pests or fungus before adding fertilizer.

More problems with Black poplar

Back to the Black poplar guide

This article was generated with AI on from the plant’s care profile and is general information, not horticultural advice. Read about how we build these guides.