Effectiveness of weed killer after watering

Old 07-24-19, 04:51 AM
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Effectiveness of weed killer after watering

Yesterday I applied Bayer/BioAdvanced Season Long Weed Control For Lawns. We have spotted spurge and some other weeds I'm trying to get rid of. I followed the instructions and lightly watered in about 1.5 hours after application. I forgot to disable my sprinklers and the front yard zones watered this morning... The bottle says it's rain proof after 1 hour... would this impact the effectiveness of the weed killer?

Old 07-24-19, 06:18 AM
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The bottle says it's rain proof after 1 hour.
Can only go by what the manufacturer states, only time will tell!
Old 07-27-19, 12:22 PM
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in my experience with a vast variety of weed/grass killers is that NOT one of them actually last as long as claimed by manufacturer.
My guess is that they do their testing in a lab under very specific conditions.... however, even when I used the strongest, most residual products that claim 1 year protection from growth.....I have seen new growth within 3 months at best.

I am guessing you could do something that may not be exactly legal - as you must not modify the label direction, due to potential damage to environment, contaminating run-off water etc.... but you could buy highly concentrated product and use it at much higher level (say the label says to use 8oz per gallon - you could do 16oz or even 24 per gallon.....) At the end I still think it's all about the amount of rain and how quickly the product will get washed away and diluted below effective concentration.

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