No matter how carefully you apply glyphosate as the 'weed' dies the
chemical will dissolve into the soil and affect your vegetable plants,
and you when you eat them, if you get any. You can mulch but weeding
crops is always a physical chore; sweat/labor. My garden is 50' X 50'
on the ground, during the growing season I use weed block cloth as
much as possible, the quality grades will last 15-20 years... after
fall tilling I cover every sq in with cloth for winter... saves a
tremendous amount of weeding come spring when weeds emerge
prolifically before the ground is dry enough to work.
Glyphosate decomposes into harmless residue in 3-5 days after it is
I generally avoid using glyphosate because it is hard to keep it away
from plants I do not want to kill. That is why I suggested a
grass-specific herbicide to the originator of this thread.
David E. Ross
Climate: California Mediterranean, see
The median half-life of glyphosate in soil has been widely studied;
values between 2 and 197 days have been reported in the literature.7,48
A typical field half-life of 47 days has been suggested.4 Soil and
climate conditions affect glyphosate's persistence in soil.1 See the
text box on Half-life.
The "half-life" is the time required for half of the compound to
break down in the environment.
1 half-life = 50% remaining
2 half-lives = 25% remaining
3 half-lives = 12% remaining
4 half-lives = 6% remaining
5 half-lives = 3% remaining
Half-lives can vary widely based on environmental factors. The
amount of chemical remaining after a half-life will always depend on the
amount of the chemical originally applied. It should be noted that some
chemicals may degrade into compounds of toxicological significance.
Glyphosate is relatively stable to chemical and photo
decomposition.6 The primary pathway of glyphosate degradation is soil
microbial action, which yields AMPA and glyoxylic acid. Both products
are further degraded to carbon dioxide.3
Glyphosate adsorbs tightly to soil. Glyphosate and its residues are
expected to be immobile in soil.6
The median half-life of glyphosate in water varies from a few days
to 91 days.1
Glyphosate did not undergo hydrolysis in buffered solution with a
pH of 3, 6, or 9 at 35 °C. Photodegradation of glyphosate in water was
insignificant under natural light in a pH 5, 7, and 9 buffered
Glyphosate in the form of the product Roundup® was applied to
aquatic plants in fresh and brackish water. Glyphosate concentrations in
both ponds declined rapidly, although the binding of glyphosate to
bottom sediments depended heavily on the metals in the sediments. If
chelating cations are present, the sediment half-life of glyphosate may
be greatly increased.60
Glyphosate has a low potential to contaminate groundwater due to
its strong adsorptive properties. However, there is potential for
surface water contamination from aquatic uses of glyphosate and soil
Volatilization of glyphosate is not expected to be significant due
to its low vapor pressure.6
Glyphosate and all its salts are very low in volatility with vapor
pressures ranging from 1.84 x 10-7 mmHg to 6.75 x 10-8 mmHg at 25 °C.1,4,8
Glyphosate is stable in air.1
Glyphosate is absorbed by plant foliage and transported throughout
the plant through the phloem.3 Glyphosate absorption across the cuticle
is moderate, and transport across the cell membrane is slower than for
most herbicides.4 Because glyphosate binds to the soil, plant uptake of
glyphosate from soil is negligible.3
Glyphosate accumulates in meristems, immature leaves, and
Very little glyphosate is metabolized in plants, with AMPA as the
only significant degradation product.3
Lettuce, carrots, and barley contained glyphosate residues up to
one year after the soil was treated with 3.71 pounds of glyphosate per
Glyphosate had a median half-life of 8 to 9 days in leaf litter of
red alder and salmonberry sprayed with Roundup®.48
All surface wipe and dust samples collected from five farm
households in Iowa contained detectable levels of glyphosate ranging
from 0.0081-2.7 ng/cm2. In six non-farm households, 28 out of 33 samples
collected contained detectable levels of glyphosate ranging from
Glyphosate is deactivated upon contact with soil, idiot.
To the OP: Glyphosate applied directly to the plants you wish to kill
is fine. I find it simpler to apply it by hand. I put a heavy
plastic/rubber/nitrile glove on my hand, cover that with a cheap
cotton glove, and dip it into a bowl containing glyphosate. Then I
grab the weed with the gloved hand and stroke it. It gets a good
application without dripping or runoff. When I'm done, the gloves go
into the trash.
There are herbicides that are specific to grass. These are intended to
kill grass without harming other plants.
Go to a nursery or hardware store and read the label. Some kill only
certain kinds of grass.
David E. Ross
Climate: California Mediterranean, see
Oh, I am sorry - I was mistaking your opinions for facts. How silly of
me. Opinions, eh? Not even observations. There's nothing like an
armchair critic for telling others how it really is.
Why don't you read Frank's reply for some facts rather than opinions,
and then refer any future postings on the subject to that reply. Then
the poster can make up their own mind whether or not to use glyphosate
(or anything else for that matter).
is this a current problem or a hypothetical
i would not use glyphosate for any application
near veggies or otherwise.
it isn't benign and is persisting and accumulating
in spite of what the manufacturer claims.
if the grass infestation is minor pull them out
or dig them out (making sure to get all the roots),
if you're able to consider painting each weed you
should be able to pull the weeds out, it will
probably be much faster.
if it is major, trim off as much of the green stuff
as you can and then smother it with a few layers
of cardboard and mulch, absolutely no light or gaps
can be left because that is all the grass needs and
believe me it will find a way through.
raised beds on or near a grassy area should be
set up properly to prevent grass incursions. weed
barrier fabric underneath, keeping the edges neatly
trimmed (don't point your mower chute at the gardens,
don't string trim knocking grass seeds into the
garden, etc.). often it is better to extend the
weed barrier out from the raised bed and to mulch
that area also making it less likely for grass to
be near the gardens.
also, make sure when you add organic materials to
the raised beds that it is properly composted or
certified to be weed/grass seed free. cow or horse
manure may not be composted well enough, same thing
with grass clippings sucked up by lawn mowers (never
use this stuff unless you want a lot of weeds in
your gardens, it must be hot pile composted first).
i often bury things in the gardens, but before i do
that i make sure it isn't full of seeds and if it
has roots i make sure those roots are well dried out
so they cannot resprout.
All excellent suggestions. However even taking every precaution weeds
will come/gardening is work. Also I once had the not so bright idea
to cover large sections of my garden with cardboard and to leave it
over winter... made a wonderful home for voles... among other plants
they ate the roots on my blueberry bushes and rug junipers... got all
the blueberries to heal but for three, the once gorgeous rug junipers
are no more. For mulching a vegetable garden I strongly suggest weed
block cloth, voles don't seem to find it attractive to make their
homes, but they love cardboard and they also like wood chips
especially pine bark nuggets. Once the subteranean critters establish
a home they don't like to move and I refuse to use poison... sometimes
pouring ordinary household ammonia into their entries repels them but
These work very well for me:
(Amazon.com product link shortened)
I have four in my vegetable garden and a half dozen around my house
amongst the foundation plantings, they've been working unfailingly for
nigh on seven years... I think the solar version is a lot better than
changing batterys. They don't recommend leaving them in the ground
where freezing and snow occurs but I do with no problem, I just push
them in so that 3" extends above ground. Considering how long they
last and how well they work $20 per is cheap.
Amazon placed the wrong text for the Solar Spikes... they take
rechargeable batteries (supplied), they also make the Non-solar type
that need D cells changed... go here:
Lowe's sells them too, that's where I discovered them and bought my
first two... next trip they were sold out so I ordered from Amazon.
Apparently they now make a Pro version of Solar Spike (see above) that
you can insert the rechargeable batterys but I have the original that
come with rechargeable batterys already inserted and cannot be
accessed. Next time I will try the Pro version, as they say those
cover a much larger area. I know they work, at least here in my soil
(apparently they don't work well in dry/sandy soil). A few weeks
after I set the solar spikes out the voles moved over to my neighbor's
yard over 1,000 feet away.
yep. i like to make the work as easy and
as multi layered as possible. the soil here
really can use all the organic materials i can
once in a while i'll see a vole, but not that
often, instead we have a good population of chipmunks
and mice around and that seems to keep the feral
cats and the neighbor's outdoor cats well fed.
I have indoor cats but I have a whole community of ferral cats that I
feed in my barn, mostly they prefer what they kill, most won't eat cat
food. They live in my barn because I supply heated houses, it gets
down into the minus twentys and thirties here in winter. Heating the
houses costs very little (40 watts) but the heat keeps them alive...
and I make sure there is always food and water... I have heated water
bowls too. Today I set up a second heated house. The population is
growing. I trap as many as I can and bring them to the Vet to be
fixed but most can't be caught. The cats are left behind when summer
people leave, they leave dogs too but dogs have very poor survival
skills so don't last long. The cats are much better at surviving and
form communities. Most of the locals feed the feral cats, this is a
farming commuity, the cats earn their keep.
On Tue, 04 Nov 2014 19:29:10 +0000, Jeff Layman wrote:
Brooklyn may not wish to make observations of / for his posts.
However to assist you and Moe DeLoughan who from your posts I assume to
be Monsanto stooges / strawmen, I suggest that visitors to this post
Google themselves variations of "Monsanto, Roundup, Spain, contaminations
One will lead to this extract:
"Monsanto, the world leader in the production of genetically engineered
(GE) staple crops, has long claimed that its broad-spectrum herbicide
Roundup is safe.
In fact, they have even used the following slogans to describe it:
"It's Safer than Mowing"
What we are now finding out -- unfortunately long after hundreds of
millions of pounds of the chemical have already been applied to U.S. soil
-- is that Roundup is proving to be a pervasive environmental threat, one
that may already be poisoning a good portion of the world's remaining
natural water supply.
Roundup is Contaminating Groundwater Supplies
The quantity of glyphosate, the active ingredient in Roundup, in the
environment has been difficult to analyze due to its physicochemical
properties, such as its relatively low molecular weight and low organic
However, a recent study used a magnetic particle immunoassay to test
for the presence of glyphosate in roughly 140 samples of groundwater from
The analysis found that glyphosate was present above the limit of
quantification in 41 percent of the samples. As noted on
GreenMedInfo.com, this indicates "that, despite manufacturer's claims, it
does not break down rapidly in the environment, and is accumulating there
in concerning quantities."
Groundwater, which is water from rain, lakes, streams or other bodies
of water that soaks into soil and bedrock, can easily become contaminated
when chemicals in the soil with low biodegradability and high mobility
empty into it.
When groundwater is used as a drinking water source, this
contamination poses a risk to animals, plants and humans alike. The U.S.
Environmental Protection Agency (EPA) explains further:
"Contaminated groundwater can hurt animals, plants, or humans
only if it is first removed from the ground by manmade or natural
processes. In many parts of the world, groundwater is pumped out of the
ground so it can be used as a source of water for drinking, bathing,
other household uses, agriculture, and industry. In addition, groundwater
can reach the surface through natural pathways such as springs.
Contaminated groundwater can affect the quality of drinking and
other types of water supplies when it reaches the surface. Contaminated
groundwater can affect the health of animals and humans when they drink
or bathe in water contaminated by the groundwater or when they eat
organisms that have themselves been affected by groundwater
That glyphosate has been detected beyond the limit of quantification
in 41 percent of groundwater samples tested reveals yet another
concerning "side effect" of its rampant use: namely, that it is not
biodegrading in the soil, as previously assumed by many scientists,
rather, is trickling down below the soil to the groundwater, where
processes of biodegradation are much slower, and the opportunity for it
to accumulate to toxic levels is much greater. These findings have
devastating environmental and human health implications, as glyphosate is
the most widely used herbicide in the world and is being found virtually
everywhere it has been tested"
The full text of which is available at:
Other URLs of interest for those who do not wish to do their own research
herbicide-soil-damage> <https://answers.yahoo.com/question/index?qid 061018160356AAmxbwP> <https://answers.yahoo.com/question/index?qid 061018160356AAmxbwP>
review-of-its-hazards-to-health-and-the-environment/> <http://www.naturalnews.com/035221_Roundup_soil_health_food_supply.html <https://uk.answers.yahoo.com/question/index?qid 080609044206AAviMAf>
our-farms-soil/> <https://au.answers.yahoo.com/question/index?qid 080920164829AAmjP5b>
Linked to Parkinson's disease
Honey Bee starvation
That gives a balanced view, though it does not necessarily support the
views and assertions of messrs Layman and DeLoughan
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