The active ingredient of that herbicide is clopyralid. It has since been removed from retail sales but is still used by landscape professionals and farmers. The advice is that if one wants to use clopyralid contaminated organic matter, that it be composted for a year. That particular information was always on the label but some folks ignored it, to the dismay of many. You can find info about it from Washington State University. See http://puyallup.wsu.edu/soilmgmt/Clopyralid.htm/. Jean in Portland, OR .... Most are destroyed by proper composting, but there have been reports of high levels of both larvacides and one particular type of herbicide (name escapes me at this time) in composted horse manure. ... -----Original Message----- From: Mark Mazer <markmazerandfm13@earthlink.net> To: Pacific Bulb Society <pbs@lists.ibiblio.org> Sent: Sun, 29 Mar 2009 2:43 pm Subject: Re: [pbs] Fertiliser-mushroom compost >I've read the best place to get your horse manure is at a race stable. >The thoroughbreds eat like the rich and famous so it makes sense that >what comes out the back end is equally rich. You are going to want to be careful using horse manure as it can have larvicides and other pharmaceutical's in it. Most are destroyed by proper composting, but there have been reports of high levels of both larvacides and one particular type of herbicide (name escapes me at this time) in composted horse manure. I never use the stuff on my edibles anymore. I'm using small amounts of poultry litter from the farm next door. It is tested yearly for the row crop farmers that use it on the fields. Mark Mazer Hertford, North Carolina USA _______________________________________________ pbs mailing list pbs@lists.ibiblio.org http://www.pacificbulbsociety.org/list.php http://pacificbulbsociety.org/pbswiki/