Be Careful When Choosing Your Mulch

Mulch ignition is becoming more and more of a concern as commercial and public facilities ban smoking inside buildings, said Larry Steward, assistant professor of horticulture at The Ohio State University Agricultural Technical Institute (Ohio State ATI). Cigarettes, matches and other smoking materials are often tossed on the ground before people enter a building. That can be a safety hazard with the wrong kind of mulch.

Red mulch is composed of either mixed hardwoods or recycled wood waste, and then dyed a red color to cover the wood impurities. One variety of red mulch is CCA Mulch that is created from chipped up wood by-products from demolished buildings, decks or other construction projects. CCA is a wood preservative, Chromated Cooper Arsenate that includes arsenic, a known carcinogen. CCA mulch has been dyed to cover up the inconsistencies, but not all dyed mulches contain CCA. To determine if the colored mulch you are purchasing does not have CCA treated wood look for the voluntary label by the mulch and soil council stating certified mulch.

Industrial – This is the lowest grade of products called mulch. It is made from industrial wastes like old pallets, construction wood, etc.
It is often chemically burned black with industrial waste and sometimes will rub off in your hand and it is often dyed various colors. It often contains arsenic from CCA treated waste wood. It has a very high carbon to nitrogen ratio and robs nitrogen and other nutrients from the soil for a long time. It may be extremely alkaline and high in toxic salts.

The Ohio State University Agricultural Technical Institute (Ohio State ATI)

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