Autumn joy sedum brown spots - Ask Extension
One of my autumn joy sedum has these grey/brown spots and leaves falling off. It's by the street and doesn't get watered except for rain. What do you ...
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Autumn joy sedum brown spots #940580
Asked July 26, 2026, 7:27 PM EDT
One of my autumn joy sedum has these grey/brown spots and leaves falling off. It's by the street and doesn't get watered except for rain. What do you think is causing this and what should I do for the plant?
Hennepin County Minnesota
Expert Response
Thank you for writing.
This is either powdery mildew https://pnwhandbooks.org/plantdisease/host-disease/sedum-powdery-mildew
or botyris https://ipm.ucanr.edu/home-and-landscape/botrytis-blight-or-gray-mold/#gsc.tab=0
In addition, those scalloped areas on leaves are signs of insects feeding on the leaves. You should be able to see them on the underside of leaves. https://bygl.osu.edu/node/2061
What to do?
1 Your plants are crowded although the picture does not allow me to see how big they are. You can divide in the spring or cut them in half now with a sharp shovel, leaving one half in place. Dig out the other half and fill the hole with garden soil.
https://www.gardeningknowhow.com/ornamental/cacti-succulents/sedum/dividing-sedum-plants.htm
2. Take a scissors, dip and wiper with lysol, and snip off dead and dying leaves. Reclean the snips as you move from plant to plant.
Feel free to write back
This is either powdery mildew https://pnwhandbooks.org/plantdisease/host-disease/sedum-powdery-mildew
or botyris https://ipm.ucanr.edu/home-and-landscape/botrytis-blight-or-gray-mold/#gsc.tab=0
In addition, those scalloped areas on leaves are signs of insects feeding on the leaves. You should be able to see them on the underside of leaves. https://bygl.osu.edu/node/2061
What to do?
1 Your plants are crowded although the picture does not allow me to see how big they are. You can divide in the spring or cut them in half now with a sharp shovel, leaving one half in place. Dig out the other half and fill the hole with garden soil.
https://www.gardeningknowhow.com/ornamental/cacti-succulents/sedum/dividing-sedum-plants.htm
2. Take a scissors, dip and wiper with lysol, and snip off dead and dying leaves. Reclean the snips as you move from plant to plant.
Feel free to write back
