Hello,

Thank you for your 3 photos and question about your euonymus showing summer necrosis. There are a myriad of free online resources available to the public based upon research conducted at various University Horticulture Departments. One such resource comes from the Clemson Extension that details various pests and diseases that can affect the health of euonymus: https://hgic.clemson.edu/factsheet/euonymus-diseases-insect-pests/ Pests can be one of the main causes of leaf drop in euonymus plants. That’s why it’s important to regularly check your plant for any signs of insect activity. If you see any pests, you can try spraying the plant with a garden hose or using a pesticide. I cannot see any pests in your photo; have you checked? Especially the underside of the leaves?

The above Clemson article includes many photos depicting leaves’ response to various problems, but I do not see any “matches” for the leaf damage that your plant exhibits? Curling and burning is more how I’d describe the leaf damage I see in your photos. A chemical agent or pet urine can cause this; Have there been any pets repeatedly visiting your shrub? Have any sprays been applied?

One of your photos clearly shows stem dieback; when you perform the ‘snap test’ are the other branches dead as well? Euonymus do not thrive in wet conditions; maybe they are getting too much water due to a neighbor’s sprinklers?

How long has your plant grown in this spot? How much water and sun is it getting? With the extremely hot temperatures we have had this summer, many plants are showing signs of stress.

I’m not sure where you live, but you might consider taking some samples of your plant to the plant diagnostic clinic at the CSU Spur Campus in a neighborhood just north of downtown Denver https://agsci.colostate.edu/agbio/plantclinic/
On their website is a ‘contact us’ area. The email to use to contact them is <personal data hidden> and the phone number is<personal data hidden>. Good Luck.

On 09/05/2023 11:00 AM MDT Ask Extension <<personal data hidden>> wrote: