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Q: "Round-up" removal and soil restoration ( Answered 5 out of 5 stars,   4 Comments )
Subject: "Round-up" removal and soil restoration
Category: Family and Home > Gardening
Asked by: scotttygett-ga
List Price: $14.00
Posted: 11 Apr 2005 18:47 PDT
Expires: 11 May 2005 18:47 PDT
Question ID: 508121
I've used Monsanto's "Round-up" a few times before, and it hasn't
always worked out predictably. For one thing, bermuda #9 isn't a
"weed" per se, but it's what we try to get rid of and it's really
aggressive. And when it does finally give out, it may have taken a
couple of applications of "round-up" and the seed we plant doesn't
like what's left. "Round-up" is supposedly eaten up my algae, which is
good news, except that the only thing we've grown in some patches has
been algae. Round-up seems to be hanging on. I contacted the company
asking if I could do something to kill the round-up sooner like
squirting the area with hydrogen peroxide and at that time they just
repeated the label back to me.
So, what destroys "round-up" completely, so I can be reasonably sure
my dead soil has a shot when I dump six bags of fertilizer on it.
Incidentally, I'm in LA, and we have pretty good soil here.
I'm trying to list this in a couple of places, because some folks who
know chemistry can't garden, etc...

Request for Question Clarification by tlspiegel-ga on 11 Apr 2005 22:31 PDT
Hi scotttygett,

In reference to your comment about letting your question stay up a
couple more days. If no other researcher has posted a remedy by April
13th, I'll be happy to answer the question.

As for my semi-personal experience with Roundup:  a friend of mine
also tried to kill a large lawn of Bermuda using Roundup.  Roundup
worked.  Being very patient, he waited a year before planting anything
in that area.  After a year, he tilled the soil, threw down some
fertilizer along with fresh soil, and now has a nice quite large and
pretty garden growing.  :)

I know the label states waiting a shorter amount of time, but he was
told to give it a year for the herbicide to ease out of the ground.

Best regards,

Request for Question Clarification by tlspiegel-ga on 11 Apr 2005 22:43 PDT
More here:

See second Q. and A.

Clarification of Question by scotttygett-ga on 12 Apr 2005 06:07 PDT
Thanks tlspiegel:

I just put in a couple of hours myself after your admirable work. The
13th sounds fine.

I'm no chemist, and it probably helps with this.
Strong acid (HCl) and salt may help leach the excess out of soil, but
definitely wouldn't decompose it.
It's supposedly like an amino acid chemically, which sort of goes with
its breaking down by rotting eventually.
There is apparently a particular system blocked that one might be able
to supplement with missing: 5-enol Pyruvylshikimate-3- phosphate
synthase (EPSPSase), or its products -- phenylalanine, tyrosine and
tryptophane, and/or their products, phytoalexins, plastoquinone,
alkaloids, cinnamate, coumarin and flavonoids.
Goofy, huh?

One anecdote suggested lime or other alkali might speed decomposition,
but it wasn't confirmed anywhere, except possibly a composting page. I
think there was some general encouragement for tilling the dirt to get
the solution moving. Similarly, a suggestion that metalloenzynmes
might interact didn't appear much in searching. Those seem to have
been dead ends.

Reductive amination was another lead that detoured through citric acid
and penicillum (bread mold?); and then there was the whole phosphorous
thing, and the idea of using calcium or magnesium to precipitate the

I expected beano or pepsin or papain to be mentioned, but no such
luck. The only obvious entry was activated charcoal.

Important question, whether or not they splced mold to corn to make it resistant.

Request for Question Clarification by tlspiegel-ga on 12 Apr 2005 08:26 PDT
Hi scottygett,

Thank you for your clarification.  I'll keep an eye out for anything
new to develop on your question.  I'll also poke around some more on
the net and make a few calls to see if I can come up with anything
more definitive for you.

Best regards,

Clarification of Question by scotttygett-ga on 13 Apr 2005 02:49 PDT
Thanks much. I have a mind to post it separately in chemistry with a
chemical diagram to see if anyone will look at it and go, oh, "that
ester pair wouldn't stand a chance against weak hydrogen peroxide, bla
bla bla." (Homer Simpsons voice) That will be another post however.
Thanks for the extra attention -- Happy April 13th!

Request for Question Clarification by tlspiegel-ga on 13 Apr 2005 08:40 PDT
Hi scottygett,

I've locked your question and will be posting an answer shortly.  Stay tuned!
Happy April 13th to you to.  :)

Best regards,
Subject: Re: "Round-up" removal and soil restoration
Answered By: tlspiegel-ga on 13 Apr 2005 09:53 PDT
Rated:5 out of 5 stars
Hi scotttygett,

Thank you for requesting me to answer your question.

I've re-posted the original material posted in clarifications and
comments - and below that you'll find more information that might be
helpful to you.

Bermuda is dead


See second Q. and A.


Herbicide Injury to Yard and Garden Plants

Inactivation Activated Charcoal

"Most soil-active herbicides can be inactivated or absorbed by
applying activated charcoal at a rate of 1 to 2 lbs. per 100 sq. ft.
and incorporating it to a depth of 6 inches. Early treatment is
essential to prevent the movement of herbicide deeper into the


Soil Replacement

"In some cases, it may be necessary to completely remove the
contaminated soil and replace it with clean soil. Be absolutely sure
that the injury is the result of herbicide contaminated soil before
resorting to this costly procedure."


Glyphosate Factsheet  (2 pages)

see Figure 6 Persistence or Glyphosate in U.S. Agricultural Soil Map of US.

"Note: Numbers, as well as the length of the columns, give the
half-life, in days, of glyphosate in soil. Half-life is the length of
time required for half the applied glyphosate to break down or move
out of the test site.

Source: U.S. EPA. Environmental Fate and Effects Division. 1993.
Pesticide environmental fate one line summary; Glyphosate. Washington,
D.C., May 6.

Glyphosate's persistence in soil varies widely, but its half-life in
agricultural soil can be over 4 months."

Persistence and Movement in Soil

"Glyphosate's persistence in soil varies widely, so giving a simple
answer to the question "How long does glyphosate persist in soil?" is
not possible. Half-lives (the time required for half of the amount of
glyphosate applied to break down or move away) as low as 3 days (in
Texas) and as long as 141 days (in Iowa) have been measured by
glyphosate's manufacturer. (See Figure 6.) Initial degradation
(breakdown) is faster than the subsequent degradation of what remains.
Long persistence has been measured in the following studies: 55 days
on an Oregon Coast Range forestry site: 249 days on Finnish
agricultural soils; between 259 and 296 days on eight Finnish forestry
sites; 335 days on an Ontario (Canada) forestry site; 360 days on 3
British Columbia forestry sites; and, from 1 to 3 years on eleven
Swedish forestry sites. EPA's Ecological Effect's Branch wrote, "In
summary, this herbicide is extremely persistent under typical
application conditions."

Glyphosate is thought to be "tightly complexed [bound] by most soils"
and therefore "in most soils, glyphosate is essentially immobile."
This means that the glyphosate will be unlikely to contaminate water
or soil away from the application site. However, this binding to soil
is "reversible." For example, one study found that glyphosate bound
readily to four different soils. However, desorption, when glyphosate
unbinds from soil particles, also occurred readily. In one soil, 80
percent of the added glyphosate desorbed in a two hour period. The
study concluded that "this herbicide can be extensively mobile in the
soil ....""


More here:

Roundup - An Article that Every Gardener Needs to Read

Turfgrass Forums

Sustainable Soil Management


I answered another question that might be of interest to you:



Lastly, in order to find definitive information regarding your
specific area, why not make a call to your Local County Extension
Office and see what they suggest.

"These offices are staffed by one or more experts who provide useful,
practical, and research-based information to agricultural

- Click on your state (California is divided into Northern and Southern areas)
- Click on the map to select your county
- You'll be directed to a page with all contact information



Roundup glyphosate soil restoration
herbicide removal restore soil
Monsanto Roundup half-life


Best regards and Good Luck to you,
scotttygett-ga rated this answer:5 out of 5 stars and gave an additional tip of: $5.00
Aquarium supply stores, including Petco's aquarium shelves, sell
activated charcoal for about $10 per pound; the best price I've found
online is $5. $50-100 for a standard 30x30 lawn is manageable,
considering that much fertilizer will go down. There's a business
opportunity here probably, or two, as I would rent a few goats to eat
the lawn without hesitation.
Thanks for your efforts.

Subject: Re: "Round-up" removal and soil restoration
From: tlspiegel-ga on 11 Apr 2005 19:13 PDT
Perhaps this thread at will be helpful to you.
Subject: Re: "Round-up" removal and soil restoration
From: scotttygett-ga on 11 Apr 2005 21:50 PDT
REALLY close to answering my question. It said that if I plant fescue
grass with residue "Round up" in the ground that the lawn will be dead
in a year but that after that time another planting should take.

At least that confirms experience as far as the lawn dying goes.

No luck finding a remedy, eh?

Please leave this up a little longer, but come back in a couple of
days and collect your fee if no other experts know what kills "Round
up." I hope this is okay with Google policy.
Subject: Re: "Round-up" removal and soil restoration
From: tlspiegel-ga on 13 Apr 2005 15:25 PDT
Hi scottygett,

Thank you for the 5 star rating, comments and generous tip!  :)

Rent a few goats!  lol  Funny...  

Best regards,
Subject: Re: "Round-up" removal and soil restoration
From: crabcakes-ga on 13 Apr 2005 17:26 PDT
Goats DO help, but not with weeds/grasses contaminated with herbicies, please.

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