Crabgrass preemergent - Lebanon Barricade 0.38%

[Achigurh]

Hello, I was wondering if anyone had experience with this product. This is my first spring with the chickens, and I've been letting them free-range in the backyard. I usually put down Barricade crabgrass preemergent every year (if I don't the entire lawn is overrun by crabgrass). The seller told me just to pen them up for a week until the granules disappear. The manufacturer said, "we don't recommend allowing animals to graze on grass treated with this fertilzer," but couldn't tell me specifically if there was a time after which is was safe to allow the chickens out. I assume all of the grass will absorb the stuff to some extent...should I not let them freerange at all now, or should I wait a week or so?

Thanks for any advice.

 

[Achigurh]

I found the name of the chemical...prodiamine. Did a search on it and found that it's listed as a "possible" carcinogen (only because there is no human data on it) and "suspected" endocrine disruptor (also no human data).

I guess I should keep them penned for a bit longer than a week, maybe several weeks, and start using corn gluten meal for crabgrass prevention.

 

[mandelyn]

I stopped treating the back yard with any chemicals, and only maintain the front. I yank weeds in the back by hand and feed them to the birds, and we do a heavy reseeding in the back about 3 times a year to keep it thick and reasonably weed free. The thicker the grass is, the less weeds that can get a foot hold.

Not sure if that chemical is systemic to the grass, and being absorbed, or if it only affects the soil and crabgrass. That's the question to ask the manufacturer, does the lawn grass absorb the chemical. The birds will eat that grass, no doubt.

 

[Achigurh]

I did ask them that specifically, but they could only give me a blanket statement that they don't recommend allowing animals to graze on grass treated with it. I'll think I'll have to stop using the chemicals also, I hate keeping them penned up. I usually don't use weedkiller, only the crabgrass preemergent, lime once a year, and fertilizer twice a year.

Thanks for the response.