So far, all my spent coffee grinds, have ended up in my
compostor ( I believe there was a thread on ukrg last
year).

After reading the following article, I'll separate the
coffee and use it as a spray next year, on the
allotment. It also mentions tea leaves as a good source
http://preview.tinyurl.com/34gjnw2

Ah thank you, I didn't know that myself. How very interesting, I have been told that salt helps, a friend of mine said that salt can get rid of slugs however I wouldn't like to try it out... I was also told you could buy poisons for slugs but if birds eat the slugs after it can make them sick..

Anyway, this is very interesting. Who would have thought that slugs would hate coffee?

On 22/11/2010 23:54, Bertie Doe wrote:
So far, all my spent coffee grinds, have ended up in my compostor ( I
believe there was a thread on ukrg last year).

After reading the following article, I'll separate the coffee and use it
as a spray next year, on the allotment. It also mentions tea leaves as a
good source http://preview.tinyurl.com/34gjnw2

It is more effective just to spread the coffee grounds around sensitive
plants like hostas and delphiniums. Turning it into a spray isn't worth
the effort. Most things of plant origin that we consume as stimulants
and interesting tastes were intended for chemical warfare against plant
parasites or fungi. It is sheer good luck that they do us no harm.

Regards,
Martin Brown

Thanks hollierose and Martin. What I should have
mentioned in the above post, is the fact that most
coffee shops are happy to donate their spent espresso
pucks and filter grounds. In fact Starbucks HQ in the
States, advertise the fact. I suggest you phone your
local coffee shop first and also bring along a couple
of s/mkt carrier bags.

As to doseage - I'm unsure. I'll go back to
alt.coffee-moderated later (where I first saw the above
link) and get their opinion. I will experiment in 2011
and post back. It would be great if the cabbage white
butterfly was allergic?? - fat chance!!!

Bertie

In article ,
Martin Brown wrote:

It is more effective just to spread the coffee grounds around sensitive
plants like hostas and delphiniums. Turning it into a spray isn't worth
the effort. Most things of plant origin that we consume as stimulants
and interesting tastes were intended for chemical warfare against plant
parasites or fungi. It is sheer good luck that they do us no harm.

Not luck! We are evolved from a long history of plant eaters, and
have a very high resistance to many such chemicals - caffeine being
one. And we don't usually consume the plants which contain ones to
which we have no resistance, however interesting they are.


Regards,
Nick Maclaren.

On 22/11/2010 23:54, Bertie Doe wrote:
So far, all my spent coffee grinds, have ended up in my compostor ( I
believe there was a thread on ukrg last year).

After reading the following article, I'll separate the coffee and use it
as a spray next year, on the allotment. It also mentions tea leaves as a
good source http://preview.tinyurl.com/34gjnw2

Has this article just been published in ScienceNews? It refers to a 27
June edition of Nature, but Hollingsworth and Campbell (two authors
mentioned) published the paper "Pest Control: Caffeine as a repellent
for slugs and snails" in the 27 June 2002 edition of Nature
(http://www.nature.com/nature/journal.../417915a.html).

Assuming that it works well, probably the main reason why caffeine is
not used commercially against slugs and snails is that it is not patentable.

--

Jeff

In article , hollierose.76187b6
@gardenbanter.co.uk says...
a friend of mine said that salt can get rid
of slugs


Many years ago (50+!) I had an aunt who every evening used to go out
with a pot pf salt and a tea spoon and sprinke a little on any slug she
found. Not a pleasant sight, as the slugs sort of bubbled up as they
died, but were gone by the morning.

"Jeff Layman" wrote in
message ...
On 22/11/2010 23:54, Bertie Doe wrote:
So far, all my spent coffee grinds, have ended up in
my compostor ( I
believe there was a thread on ukrg last year).

After reading the following article, I'll separate
the coffee and use it
as a spray next year, on the allotment. It also
mentions tea leaves as a
good source http://preview.tinyurl.com/34gjnw2

Has this article just been published in ScienceNews?
It refers to a 27 June edition of Nature, but
Hollingsworth and Campbell (two authors mentioned)
published the paper "Pest Control: Caffeine as a
repellent for slugs and snails" in the 27 June 2002
edition of Nature
(http://www.nature.com/nature/journal.../417915a.html).

Looks like it may be an old article.

Assuming that it works well, probably the main reason
why caffeine is not used commercially against slugs
and snails is that it is not patentable.


As we know, the compounds in coffee are numerous. If
'Big Chemistry" could isolate the one that kills slugs
....... there would be another ££££ big killing

wrote in message
...
In article ,
Martin Brown
wrote:

It is more effective just to spread the coffee
grounds around sensitive
plants like hostas and delphiniums. Turning it into a
spray isn't worth
the effort. Most things of plant origin that we
consume as stimulants
and interesting tastes were intended for chemical
warfare against plant
parasites or fungi. It is sheer good luck that they
do us no harm.

Not luck! We are evolved from a long history of
plant eaters, and
have a very high resistance to many such chemicals -
caffeine being
one. And we don't usually consume the plants which
contain ones to
which we have no resistance, however interesting they
are.


I may need your help with the maths here, as it may be
less hassle to spray the salad area on the allotment
with a gallon of fresh coffee - rather than bothering
with saving up old spent grounds.

The following are US capacity measurements:
http://preview.tinyurl.com/34gjnw2

"A 4-ounce solution of 2 percent caffeine applied to
the soil of 4-inch greenhouse pots devastated garden
slugs"

I assume they mean 4 oz of coffee contains 2% of pure
caffeine. We have to speculate as to the strength and
type of coffee and amount used.

There's no real need to use 'proper' coffee, as instant
coffee lies neatly between arabica and robusta,
according to:-
http://coffeechemistry.com/index.php...in-coffee.html

So to summarise, there are 32 cups (4 oz) in a US
gallon. I'm estimating 0.25 oz of instant per cup, so
an 8 oz jar would produce a gallon of Nescafe bliss.
Make a small adjustment for my 5 litre sprayer etc. If
it's effective and a gallon lasts all Summer, then it
could prove to be an economic method of pest control.

"Bertie Doe" wrote ...

So far, all my spent coffee grinds, have ended up in my
compostor ( I believe there was a thread on ukrg last
year).

After reading the following article, I'll separate the
coffee and use it as a spray next year, on the
allotment. It also mentions tea leaves as a good source
http://preview.tinyurl.com/34gjnw2

The only problem I see is that DEFRA have not given it a licence to be used
as a pesticide, it has not been tested as such, and we therefor do not know
what damage it would cause to the environment as a whole. It might also kill
birds and others that eat the contaminated slugs for example, it might do
irreparable damage to the soil flora/fauna.

--
Regards
Bob Hobden
W.of London. UK

In article ,
Bob Hobden wrote:
"Bertie Doe" wrote ...

So far, all my spent coffee grinds, have ended up in my
compostor ( I believe there was a thread on ukrg last
year).

After reading the following article, I'll separate the
coffee and use it as a spray next year, on the
allotment. It also mentions tea leaves as a good source
http://preview.tinyurl.com/34gjnw2

The only problem I see is that DEFRA have not given it a licence to be used
as a pesticide, it has not been tested as such, and we therefor do not know
what damage it would cause to the environment as a whole. It might also kill
birds and others that eat the contaminated slugs for example, it might do
irreparable damage to the soil flora/fauna.

Yeah. And it might super-stimulate the slugs, so they go racing
round the garden, or even sprout wings and fly.

Given the massive experience we have of composting them in open
heaps, the effect on birds is almost certainly nil to negligible,
and we can be certain that it won't cause irreparable damage to
the soil flora and fauna.

On 23/11/2010 23:56, Bertie Doe wrote:

wrote in message ...
In article ,
Martin Brown wrote:

It is more effective just to spread the coffee grounds around sensitive
plants like hostas and delphiniums. Turning it into a spray isn't worth
the effort. Most things of plant origin that we consume as stimulants
and interesting tastes were intended for chemical warfare against plant
parasites or fungi. It is sheer good luck that they do us no harm.

Not luck! We are evolved from a long history of plant eaters, and
have a very high resistance to many such chemicals - caffeine being
one. And we don't usually consume the plants which contain ones to
which we have no resistance, however interesting they are.

I am sure you know what I mean. You have to admire the guy who ate the
first chilli or maybe did it the second time knowing what to expect!.

Some of the things we can eat are surprising given how bad they are for
other mammals - chocolate is lethal to dogs for instance and soya beans
and some other legumes wreck most rodents reproduction cycle.

I may need your help with the maths here, as it may be less hassle to
spray the salad area on the allotment with a gallon of fresh coffee -
rather than bothering with saving up old spent grounds.

The following are US capacity measurements:
http://preview.tinyurl.com/34gjnw2

"A 4-ounce solution of 2 percent caffeine applied to the soil of 4-inch
greenhouse pots devastated garden slugs"

I assume they mean 4 oz of coffee contains 2% of pure caffeine. We have
to speculate as to the strength and type of coffee and amount used.

I wouldn't assume that at all. 4 oz of coffee will likely contain
0.03-0.06g of caffeine. Taking 4oz as roughly ~100g = 0.05% caffeine
content. A 2% caffeine solution would be very very strong coffee the
sort that you could stand the spoon up in.

Espresso coffee can contain up to 2g/Litre caffeine which is 0.2%!

There's no real need to use 'proper' coffee, as instant coffee lies
neatly between arabica and robusta, according to:-
http://coffeechemistry.com/index.php...in-coffee.html


So to summarise, there are 32 cups (4 oz) in a US gallon. I'm estimating
0.25 oz of instant per cup, so an 8 oz jar would produce a gallon of
Nescafe bliss. Make a small adjustment for my 5 litre sprayer etc. If
it's effective and a gallon lasts all Summer, then it could prove to be
an economic method of pest control.

I doubt it will last all summer (though it might in a greenhouse) as
caffeine is pretty water soluble and will migrate into the ground. Use
the coffee grounds directly on the soil and you might have a useful
effect. I have tried it and cannot decide if it works or not. Slug
pellets certainly do have the right effect and very quickly.

Regards,
Martin Brown

On 24/11/2010 09:53, Janet wrote:
In , says...

In ,
Bob wrote:

The only problem I see is that DEFRA have not given it a licence to be used
as a pesticide, it has not been tested as such, and we therefor do not know
what damage it would cause to the environment as a whole. It might also kill
birds and others that eat the contaminated slugs for example, it might do
irreparable damage to the soil flora/fauna.

I doubt that very much. The chemical caffeine is not that nasty.
Curiously the LD50 for caffeine is about the same as pure glyphosate.

Yeah. And it might super-stimulate the slugs, so they go racing
round the garden, or even sprout wings and fly.

Given the massive experience we have of composting them in open
heaps, the effect on birds is almost certainly nil to negligible,
and we can be certain that it won't cause irreparable damage to
the soil flora and fauna.

If broken up tea/coffee leaves contained an effective
pesticide/deterrent/herbicide I'd expect tea/coffee plantations to be
pretty pest-proof/ weed proof, but they aren't. Growers contend with
multiple weeds/pests.

That doesn't follow at all. There are pests specific to a given host and
static monoculture like tea or coffee plantations always create problems
with the wrong pests finding a huge concentration of host plants.
Nicotine in tobacco plants is another extremely potent toxic insecticide
(extracts were even used as such in the past) but tobacco plants still
need protection from the various pest insects that have co-evolved to
tolerate or avoid the poison.

http://www.ikisan.com/links/ap_tobac...nagement.shtml

Regards,
Martin Brown

On 24/11/2010 10:57, Janet wrote:
In ,
says...

I doubt it will last all summer (though it might in a greenhouse) as
caffeine is pretty water soluble and will migrate into the ground. Use
the coffee grounds directly on the soil and you might have a useful
effect. I have tried it and cannot decide if it works or not.

IME certain textures, such as sand, fine grit, wood ashes, and rough
leaves like comfrey and dried bracken, do have some protective
deterrent/ repellent effect as slugs don't like crossing them; maybe
coffee grounds work that way.

Wood ashes are pretty alkaline. Charcoal and the last bits of coke coal
seem to work for a while as slug deterrents. They don't like the rough
surface. But I think the coffee grounds effect is mainly chemical.

Regards,
Martin Brown

On Nov 24, 12:30*pm, Martin Brown
wrote:
On 24/11/2010 10:57, Janet wrote:

In ,
says...

I doubt it will last all summer (though it might in a greenhouse) as
caffeine is pretty water soluble and will migrate into the ground. Use
the coffee grounds directly on the soil and you might have a useful
effect. I have tried it and cannot decide if it works or not.

* *IME certain textures, such as sand, fine grit, wood ashes, and rough
leaves like comfrey and dried bracken, do have *some protective
deterrent/ repellent effect as slugs don't like crossing them; maybe
coffee grounds work that way.

Wood ashes are pretty alkaline. Charcoal and the last bits of coke coal
seem to work for a while as slug deterrents. They don't like the rough
surface. But I think the coffee grounds effect is mainly chemical.

Regards,
Martin Brown

Now if coffee would work on Vine weevil