Is this fungus contagious to my other plants?

Yes, the spores can easily travel through the air to nearby plants. Keep affected plants isolated until the spots are gone.

Should I cut the whole plant back?

Only if the mildew is everywhere. Otherwise, just prune the worst parts and improve the airflow around the plant.

Trailing Lantana: spots, causes and fixes

Check these first

Rub a spot with your finger to see if it wipes off like powder.
Check if the plant is in a shaded or crowded area.
Look for signs of moisture staying on the leaves overnight.

Likely causes

Powdery mildew
Most likely
How to tell: The leaves look like they have been dusted with white flour. It usually starts on older leaves and spreads if the air is humid and still.
What to do: Remove the most heavily affected leaves and dispose of them in the trash. Spray the remaining foliage with a mixture of 1 tablespoon of baking soda in 1 gallon of water.
Lack of direct sun
Possible
How to tell: The plant is in a shady spot where the leaves stay damp for too long. Lantana needs full sun to keep the foliage dry and healthy.
What to do: Move your container to a spot that gets at least 6 to 8 hours of direct sun daily. If it is in the ground, trim back overhanging tree branches to increase light exposure.

Leaf spots on other plants

Find out what's wrong with your trailing lantana

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 spots cover most of the foliage and the leaves start to curl or turn brown, the fungus is taking over. Treat it immediately to prevent the plant from losing its vigor.

Stopping it coming back

Water only at the base of the plant to keep the leaves dry. Ensure the plant has plenty of room for air to move through the branches.

Trailing Lantana: spots? Check yours with a photo

Every plant is a little different. Take a photo of your trailing lantana 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

Is this fungus contagious to my other plants?: Yes, the spores can easily travel through the air to nearby plants. Keep affected plants isolated until the spots are gone.
Should I cut the whole plant back?: Only if the mildew is everywhere. Otherwise, just prune the worst parts and improve the airflow around the plant.

Guides to these causes

Powdery Mildew

What are these white dusty spots on my Trailing Lantana?