Hi I have a question regarding Roundup. It was very unfortunately used in the yard before I moved in to my home. I've been living here now for about 18 months and haven't used a single chemical anywhere. I've got dandelions, mallow, clover and other nice things popping up now, are they safe to feed to my Russian tort yet?
You should be ok, but the longer you can wait the better
Thanks for replying. I was hoping it's been long enough, there's a lot of conflicting info online. I'm not even 100% sure when it was used but I found a half empty sprayer in the garage, better safe than sorry though!
Even the strongest version of RoundUp should have disappated from the soil long ago. Roundup is absorbed by the plant’s leaves more than the roots so little remains in the soil. Your healthy plants are proof the herbicide is no longer working.
There are herbicides designed to kill plants before they grow; Roundup is only effective on those already growing. If you still have the bottle it should state how long you have to wait after spraying to plant anything new; usually it’s a few days.
Even for those longer lasting herbicides we generally say wait one year before feeding.
There are herbicides designed to kill plants before they grow; Roundup is only effective on those already growing. If you still have the bottle it should state how long you have to wait after spraying to plant anything new; usually it’s a few days.
Even for those longer lasting herbicides we generally say wait one year before feeding.
I agree with Rosemary on this one. I'd feel comfortable feeding out weeds from my yard after 12 months, so definitely after 18.
EllyMae
Active Member
As Rosemary said, Roundup (active ingredient: glyphosate) is a post-emerge herbicide. It will only kill plants that have already emerged.
Also, it is quickly dissapated. Lots of factors, including sunlight, water, and soil microbes will determine how quickly it breaks down, Mainly, glyphosate breaks down from soil microbes. The studied half-life in soil is between 2 and 197 days, most commonly 47days, depending on the previous factors. Glyphosate breaks down to AMPA and glyoxylic acid. These two then break down into CO2.
For a 47day halflife, in 18months, you would have over 11half-lives. At 11half-lives, you will have only .0468% remaining.
Glyphosate breaks down even faster in water.
Any plant the Roundup was applied to, would have most likely died within a week of the application (unless it was one of the resistant weeds). Then it would have gone into the soil as the dead plant decomposed. After 18months, there would be hardley any left.
Source: National Pesticide Information Center; Glyphosate Technical Fact Sheet.
Also, it is quickly dissapated. Lots of factors, including sunlight, water, and soil microbes will determine how quickly it breaks down, Mainly, glyphosate breaks down from soil microbes. The studied half-life in soil is between 2 and 197 days, most commonly 47days, depending on the previous factors. Glyphosate breaks down to AMPA and glyoxylic acid. These two then break down into CO2.
For a 47day halflife, in 18months, you would have over 11half-lives. At 11half-lives, you will have only .0468% remaining.
Glyphosate breaks down even faster in water.
Any plant the Roundup was applied to, would have most likely died within a week of the application (unless it was one of the resistant weeds). Then it would have gone into the soil as the dead plant decomposed. After 18months, there would be hardley any left.
Source: National Pesticide Information Center; Glyphosate Technical Fact Sheet.
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