Problem with plants and grass

Asked June 6, 2019, 8:04 AM EDT

I had mulch laid on Saturday. On Saturday evening I notice my annuals looked like they were dying. On Sunday I had several perennials that the leaves were shriveling, looked brown and white. On Monday grass around beds had lost color, many more perennials had dead leaves and a few shrubs had shriveled leaves and some ground cover that looks completely dead. I am devastated. I have about 200 perennials, 13 rosebushes, several vines, ground cover in several areas. Is there anything I can do? Or will everything recover?

I believe it is from the mulch because I did nothing different this year than any other year. Could this devastation be from the mulch? and if so is it the fault of my landscaper, the supply company he picked it up from or company that made the mulch. Thank you, Cindy Potts

Livingston County Michigan

3 Responses


This looks like herbicide or other chemical damage. When was fertilizer or weed killer last applied to the lawn or garden? Is the damage near a neighbors’s lawn or garden where a herbicide spray could have drifted over? Is there a pattern- such as only one side or area has damage? If the shredded wood were causing this the plants from which the mulch was made may have had herbicide residue. Without knowing what that chemical was, testing for it is difficult and very expensive, and the residue may be gone by the time the lab would receive samples.

Removing the mulch or at least pulling it back a few inches so it doesn’t touch the plants could help the still living parts of the plants. If it hasn’t rained in your area since this happened, thoroughly rinse the plants with water. The grass edges may need reseeding or a new sod strip-

Your best bet is to diagnose the cause of the plant deaths. For a fee, MSU Plant and Pest Diagnostic lab may be able to diagnose samples of plants. Include plant samples showing the boundary where the dead and still living foliage is attached. Other than the samples you plan to submit showing this transition from living to dead tissue, you can prune off the damaged plant parts on the rest of your perennials. Include pictures with your lab samples. Give them a call first to find out exactly what to include, and when to mail them. The sooner this is done the better the chance of a diagnosis. See their website for details and phone number-

References for you-

I’m sorry you have so much damage. With some pruning your perennials should recover. Thanks for using our service.

I did send a sample to lab in oregon to test for herbicide. I had my lawn treated by the same company I have used for several years. They treated end of April. I live on an 1 1/2 acres. Neighbor on one side barely mows his lawn let alone spray anything. The other side is further away and separated by 2 driveways. My plants were all beautiful before the mulch was laid. It all happened within 36 hours. The grass looks white around most of the beds. I did put down some preen before the mulch was laid in a couple bed in shady locations that get lots of weeds. I have been gardening for 30 years and retired from the Oakland County extension so I did learn lots about plants while working there. Could this be cause from sour mulch.?


Thanks for the additional information. Here are some extension articles on sour mulch, and yes, they indicate that is possible. Note that you should be able to smell an off-odor and that the mulch is often hot to the touch-