Is citrus canker contagious?

Yes, it spreads easily through water splashes and wind. Isolate the plant if you suspect it has canker.

Should I prune the whole tree?

Only prune the affected branches. Do not remove more than one third of the tree at once.

Mandarin orange: spots, causes and fixes

Check these first

Check if the spots are raised or flat.
Look for yellow halos around the spots.
Ensure the leaves are not staying wet after watering.

Likely causes

Citrus canker
Possible
How to tell: Small, raised lesions with a yellow halo appear on leaves and fruit. These spots look corky or scabby.
What to do: Remove and destroy any infected plant parts immediately. Keep the foliage dry by watering at the base of the plant rather than overhead.
Fungal leaf spot
Possible
How to tell: Dark brown or black spots with irregular shapes appear on the leaves. They may be surrounded by a yellow ring.
What to do: Improve air circulation around the tree by thinning out crowded branches. Apply a copper fungicide if the infection is widespread.

Leaf spots on other plants

Find out what's wrong with your mandarin orange

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 spots are spreading rapidly or causing leaves to fall, take action immediately. Small, isolated spots are usually easy to manage.

Stopping it coming back

Water the soil directly to keep leaves dry and ensure your tree has plenty of space for air to move through the branches.

Mandarin orange: spots? Check yours with a photo

Every plant is a little different. Take a photo of your mandarin orange 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 citrus canker contagious?: Yes, it spreads easily through water splashes and wind. Isolate the plant if you suspect it has canker.
Should I prune the whole tree?: Only prune the affected branches. Do not remove more than one third of the tree at once.

What are these spots on my Mandarin orange leaves?

Check these first

Likely causes

Citrus canker

Fungal leaf spot

Find out what's wrong with your mandarin orange

When to worry

Stopping it coming back

Mandarin orange: spots? Check yours with a photo

Questions people ask

Guides to these causes

More problems with Mandarin orange