Many readers know that I used to have a small landscaping business and my absolute favorite soil amendment and mulch has always been Mango Mulch created and sold by Grab n' Grow on Llano Road in Santa Rosa. I buy it by the truckload, but it's also available in bag form at nurseries throughout our area. The stuff is brown gold. You can turn lousy soil into rich soil by digging it in or just laying a thick layer on top and letting the rain and worms do the work for you. Magic.

A few years ago Grab n' Grow customers got notices that a broad-leaf herbicide, Clopyralid, was showing up in the manure mixed into Mango Mulch and it was stunting the growth of plants instead of enhancing them. Grab n' Grow had to find other sources of manure that tested clean before they could sell an untainted product again. They even changed their formula to eliminate chicken manure, which has the highest level of Clopyralid. In time they found cow and horse manure that tested clean to literally NO detectable parts per BILLION in order for it to be clean enough to not harm plants - this amount translates into 6 people out of the population of the PLANET, to put it into perspective.

This chemical not only makes it through an animals' digestive system, it also doesn't break down under the intense heat of the composting process. Analyses that only tests to 100 parts per billion are not precise enough because much smaller amounts have harmful effects on plants. So Grab n' Grow had to find a company that could test to ONE part per BILLION to make sure the manure they used in their products was that clean!

Clopyralid is a unique chemical product because it's used in the animal feed business as an herbicide that targets plants in the Nightshade family - broad leafed plants like Star Thistle that grows in hay fields, etc. and dandelions that grow in lawns. Star Thistle can actually harm animal's tender mouths if it gets into feed. It makes sense that feed growers want to kill it off before it taints their crop.

So they used to spray Clopyralid, a Dow Chemical product, before these plants went to seed. In fact, because it's good on lawns for dandelions, etc., it was used extensively by homeowners as well as crop growers. But in a unique twist of fate, this chemical became a problem for the mulch industry when it showed up in grass clippings and yard waste that was being turned into garden mulch as a way of reducing materials in landfills. Yard waste is a valuable off-shoot business in the waste products world, so in the fall of 2002 California passed the Keeley Law, SB 2356 which outlawed Clopyralid used in a way that would show up in "greenwaste," recycled yard trimmings. Only qualified and licensed pest control dealers can sell any product containing this chemical, therefore it can still be used by the agriculture industry on feed crops.

Since then, Grab n' Grow found organic dairies for their cow manure, horse ranches with manure that tested clean, never did find chicken manure clean enough so never returned to using it in their products, and carried on testing batch after batch of manure to make sure they never bought tainted product. That worked for years until recently when manure piles started testing positive for Clopyralid again... even from organic dairies.

So once again, Grab n' Grow only sells Mango Mulch in bulk with a disclaimer that customers have to sign guaranteeing that they are aware of the hazards. They have a good year's supply of clean manure they are using in their bagged product - and they are searching for new clean resources. In the mean time, Don Liepold who is responsible for quality control, is researching manure-free ways to replicate the magic of Mango Mulch using clean plant products and organic fertilizers. So far the results are impressive, and I have to say a little less aromatic than manure-based MM. So avid Mango Mulch users still have the option of using the bagged product, or if all goes well, moving on to the manure-free product which Don is calling "Tango Mulch" because Grab n' Grow can't dance with the Clopyralid in manure.

But none of that solves the problem of why Clopyralid is showing up in manure once again - even in the manure from organic dairies. It's getting into animal food sources and bedding material in this clean agribusiness. This is not only an issue for gardeners, it's an issue that needs the broad attention of everyone interested in preserving the integrity of "Organic". This has much larger implications than just the impact on compost.