Commercial sourcing of leaf compost to use as mulch
I work at a large landscape architecture firm and we are debating the time honored practice of using bark mulch in the specification language of our project installations. As I am re-writing our planting specifications I am tempted to identify mulch as "thoroughly composted shredded leaf and plant matter".
My first problem was looking around to find commercial sources for this, and secondly I came upon an article that mentioned a problem of residual pesticides like Clopyralid, having detrimental effects on the plants. Can anyone advise on this. Obviously we need commercial sources for large projects. Making your own is not an option.
Philadelphia County Pennsylvania
Compost is an excellent mulch and provides the underlying soil with the necessary cooling effect in the heat of summer as well as fortifying the soil with nutrients and microbial activity. When using composted yard waste or agricultural plant material it is important to know the source. Although the use of clopyralid has been dramatically lessened over the past few years because of its residual toxicity, it is still used by some farmers and commercial lawn care companies. Clopyralid will survive the composting process and has been known to survive a horse's digestive system before entering the composting process...and still surviving.
Commercial composting facilities typically produce compost at higher temperatures than can be accomplished by homeowners and this essentially guarantees that most herbicides and other toxins are neutralized in the process, but apparently clopyralid is capable of resisting neutralization.
You may find more authoritative information by contacting the National Pesticide Information Center. 1-800-858-7378. www.npic.orst..edu