Should I throw the plant away if it has mildew?

Not at all, as it is usually treatable. Just prune the worst leaves and improve the airflow around the plant.

Does this fungus spread to other plants?

Yes, powdery mildew spores travel easily through the air. Keep infected plants away from your other greenery until they recover.

Japanese hop: spots, causes and fixes

Check these first

Rub the white spot to see if it wipes off like dust.
Check if the plant is in a spot with stagnant air.
Examine if the spots are spreading to new growth.

Likely causes

Powdery mildew
Most likely
How to tell: You will see a white, flour like coating on the surface of the leaves. It often starts on older leaves and spreads upward.
What to do: Remove the most heavily infected leaves to improve airflow. Spray the remaining foliage with a mixture of one tablespoon of baking soda in a gallon of water.
Water splashes
Possible
How to tell: Small, irregular spots that look like dried water minerals. These do not spread like fungus.
What to do: Water at the base of the plant rather than overhead. This keeps the foliage dry and prevents fungal growth.

Leaf spots on other plants

Find out what's wrong with your japanese hop

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 white patches cover more than half of the leaf surface, the plant will struggle to photosynthesize. Treat it as soon as you spot the first sign.

Stopping it coming back

Ensure your plant has plenty of space for air to circulate and avoid getting water on the leaves when you irrigate.

Japanese hop: spots? Check yours with a photo

Every plant is a little different. Take a photo of your japanese hop 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 throw the plant away if it has mildew?: Not at all, as it is usually treatable. Just prune the worst leaves and improve the airflow around the plant.
Does this fungus spread to other plants?: Yes, powdery mildew spores travel easily through the air. Keep infected plants away from your other greenery until they recover.

Guides to these causes

Powdery Mildew

What are these white spots on my Japanese hop?

Check these first

Not sure what's wrong with your japanese hop?