Should I cut off all the spotted leaves?

Cut off the ones that look really bad, but leave the healthy green parts of the leaf. The plant still needs those to photosynthesize.

Is this a disease that will kill the whole plant?

It is rarely fatal, but it can weaken the plant. Keep the area clean of dead foliage to prevent the fungus from overwintering in the soil.

Montbretia: spots, causes and fixes

Check these first

Examine the spots to see if they are spreading to new leaves.
Check if the soil is staying soggy for more than 14 days.
Ensure the plant has enough space for air to flow between stems.

Likely causes

Fungal Leaf Spot
Most likely
How to tell: You will see brown or black circular spots that may have a yellow halo around them. These often appear after periods of heavy rain or high humidity.
What to do: Remove and destroy any heavily infected leaves to stop the spread. Apply a copper based fungicide according to the label instructions if the problem persists.
Overhead Watering
Possible
How to tell: Spots appear shortly after you water the plant, specifically on the leaves where water droplets sat for a long time.
What to do: Always water at the base of the plant rather than spraying the foliage. If you must water overhead, do it early in the morning so the leaves have time to dry out before nightfall.

Leaf spots on other plants

Find out what's wrong with your montbretia

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

Small, isolated spots are usually just a cosmetic issue. Worry if the spots are merging together or causing the entire leaf to collapse.

Stopping it coming back

Improve air circulation by thinning out crowded clumps of Montbretia. Avoid wetting the leaves when you water.

Montbretia: spots? Check yours with a photo

Every plant is a little different. Take a photo of your montbretia 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 cut off all the spotted leaves?: Cut off the ones that look really bad, but leave the healthy green parts of the leaf. The plant still needs those to photosynthesize.
Is this a disease that will kill the whole plant?: It is rarely fatal, but it can weaken the plant. Keep the area clean of dead foliage to prevent the fungus from overwintering in the soil.

Guides to these causes

Leaf Spot

What are these spots on my Montbretia leaves?

Check these first

Not sure what's wrong with your montbretia?