Our locationLocust Valley, NY 11560 Call us(516) 210-5882

Can Mulching Be Toxic

What Makes Mulch Toxic

It seems that every year we at ER Landscaping of LI Inc hear from homeowners who have had problems with recently spread mulch — not by us, we might add. The problem is caused by the rapid desiccation of foliage of all plants in landscaping beds and the grass that run along these beds, which occurs within a day or two of mulching. This problem has been called hot mulch, toxic mulch, or sour mulch.

Toxic mulch generally gives out a very sour, pungent, vinegary smell, and a mulch sample that was recently submitted to the lab was tested and had a pH of 4.1! Toxic mulch is caused by badly processed, stored, managed, or “green” mulch. Chemicals produced by organisms left to ferment in a mulch pile under oxygen-deficient conditions will kill annual and perennial landscape plants. These toxic substances will often include alcohol, ammonia, hydrogen sulfide, methanol, or acetic acid. These chemicals will escape, or volatilize, soon after the mulch has been spread.

Desiccation or dying of leaves will be first seen on the bottom leaves of plants, after which it will steadily progress upward. Large perennial plants may only suffer damage on the lower leaves and will recover in time. The volatizing chemicals are often too much for smaller annual plants, and they will perish. Mulch with a pungent odor should never be spread on or around landscape beds. If lower leaf injury is noticed soon after the mulch has been spread, remove it immediately to prevent further damage. Toxic mulch can be spread in a driveway and watered in for a few days, as this will help to leach out all the toxic chemicals.

For information about the mulching services and products we have to offer, please do not hesitate to dial this number (516) 210-5882 now we are based in the Locust Valley, NY area.