Can I just mow over the spots?

Mowing can spread the fungus to healthy parts of your lawn. It is better to rake up clippings from infected areas and dispose of them in the trash.

Will the grass recover on its own?

With proper care and drier conditions, the grass can often recover. If the damage is severe, you may need to overseed the bare patches once the fungus is under control.

Roughstalk bluegrass: spots, causes and fixes

Check these first

Inspect the grass for small, sunken, circular patches.
Check if the grass stays wet for long periods during the night.
Look for dark or purple lesions on individual blades.

Likely causes

Dollar spot fungus
Most likely
How to tell: You will see small, circular, sunken patches of grass that turn straw colored or bleached. These spots often appear during warm, humid days followed by cool nights.
What to do: Apply a fungicide labeled for dollar spot if the infection is widespread. Improve air circulation by thinning out nearby plants or pruning overhanging branches. Avoid watering in the late evening so the grass blades stay dry overnight.
Leaf spot disease
Possible
How to tell: Small, dark brown or purple spots appear on the blades, often with a yellow halo. This usually happens when the grass stays wet for too long.
What to do: Remove the affected clippings after mowing to stop the spread. Water early in the morning so the sun can dry the blades quickly. Increase the mowing height slightly to reduce stress on the grass.

Leaf spots on other plants

Find out what's wrong with your roughstalk bluegrass

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

Worry if the spots start merging into large, dead patches that cover a significant portion of your lawn. Small, isolated spots are manageable with better airflow and careful watering.

Stopping it coming back

Keep your lawn well aerated and avoid overwatering in the evening to prevent the moisture buildup that fungi love.

Roughstalk bluegrass: spots? Check yours with a photo

Every plant is a little different. Take a photo of your roughstalk bluegrass 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

Can I just mow over the spots?: Mowing can spread the fungus to healthy parts of your lawn. It is better to rake up clippings from infected areas and dispose of them in the trash.
Will the grass recover on its own?: With proper care and drier conditions, the grass can often recover. If the damage is severe, you may need to overseed the bare patches once the fungus is under control.

Guides to these causes

Leaf Spot

Why does my roughstalk bluegrass have spots?

Check these first

Not sure what's wrong with your roughstalk bluegrass?