Is Preen safe for birds and wildlife? - Ask Extension
I've been told about the effectiveness of Preen as a pre-emergent weed suppressant, and am wondering if it's safe (once it's been tilled in) for birds...
Knowledgebase
Is Preen safe for birds and wildlife? #239951
Asked April 27, 2015, 4:00 PM EDT
I've been told about the effectiveness of Preen as a pre-emergent weed suppressant, and am wondering if it's safe (once it's been tilled in) for birds, pets, and wildlife. The Preen website says it is, but I wonder if it REALLY is.
Multnomah County Oregon
Expert Response
The active ingredient in Preen, Trifluran, is not considered to be hazardous to birds. The LD50 for Trifluran on bobwhite quail was greater than 2000mg of active ingredient per kilogram of bird. The LD 50 on both quail and ducks was greater than 5000mg of active ingredient per kg of bird. Both of these are EXTREMELY high rates, not likely to even be approached with legal and labelled application rates.
In general, Trifluran is not very toxic to vertebrates (including pets), with the exception of fish.
Trifluran has been shown to be toxic to earthworms, but only at levels well above permissible application rates. So, if you stay within the legal and labelled application rates, that will limit or prevent harm to earthworms.
In general, Trifluran is not very toxic to vertebrates (including pets), with the exception of fish.
Trifluran has been shown to be toxic to earthworms, but only at levels well above permissible application rates. So, if you stay within the legal and labelled application rates, that will limit or prevent harm to earthworms.
Thank you very much! That's helpful information.
