I just found out the active ingredient in Preen is trifluralin, also known as treflan. This will cause no damage to bulbs, but is mainly active against grassy weeds. Keep it off your cement because it stains. Amaze is a combo of treflan and balan, two very similar products, so whichever is more convenient is my choice. The dinitroanilines ( the class of pesticide these are) are fairly long lasting, so only one application per year would suffice in PA. The only time i've had trouble with treflan is when quantities in the soil built up (since it breaks down so slowly) and the desired plants looked virus stricken. chuck Schwartz ----- Original Message ----- From: "Dell Sherk" <dells@voicenet.com> To: <pbs@lists.ibiblio.org> Sent: Sunday, May 30, 2004 4:36 AM Subject: [pbs] Pre-emergent weed control > Does anyone out there have experience with using a pre-emergent (Preen is > the only one I know of) on bulb beds. I realize that I would lose > self-seedings of galanthus, crocus, eranthis etc. but the weeds have really > gotten out of control. > > Any help appreciated, > Dell > > -- > Dell Sherk, SE PA US Zone 6. Amaryllids, South Americans, Cyrtanthus, Hardy > bulbs, cactus and succulents, and, after a lapse, gesneriads. > > _______________________________________________ > pbs mailing list > pbs@lists.ibiblio.org > http://www.pacificbulbsociety.org/list.php