Starbucks bags up their grounds and puts them out for customers to take, free of charge.

Good to know the snails don't like it.

wanda

I think all the caffeine is flushed out of the grounds when they make coffee.

I'm constantly raiding my local SB for grounds, anyway. They make a good green for the compost bin.

Aloha,

Nathan Lau
San Jose, cA

#include (std.disclaimer)

On the compost forum, we've discussed this a few times. Apparently the concentration of caffeine to kill the slugs and snails is 5 percent, considerably more than in the morning brew. And essentially no caffeine persists in the spent grounds.

(But I've experimented with using grounds as a physical barrier -- have to be careful not to lay them too thickly, lest they form a water-repellent crust.)

I think I've read that the snails/slugs don't like to travel over anything scratchy; I imagine the coffee grounds would be rough to something that small.

I am trying to cultivate the good friendship of a nesting pair of ravens -- who LOVE escargo -- raw.

I thought what they discovered was that unbrewed coffee grounds, i.e., straight from the can, no water added, was what discouraged snails and slugs. I remember thinking that it would be a fairly expensive way to go.

Actually I just saw another thread in the Soil forum where Kelly Slocum (scientist) says the study was about caffeinated coffee (liquid) sprayed on plants killing snails and slugs.

There was a thread on this forum several years ago about coffee and plants. As I recall it wasn't too favorable about using a lot of it on or around plants. I lost several azalias when I got a little too enthusiastic with the leftover coffee.

I remember reading somewhere that hydrangeas loved grounds especially - has anyone tried this? I planted some "endless summer" a few months ago - they are either slow growers, or I am doing something wrong.

The research on using caffeine for slugs and snails was reported in the June 29, 2002, issue of Science News, below.

The concentration of caffeine that killed most slugs within 2 days was 2 percent. Coffee is typically 0.10 to 0.05 percent caffeine, and coffee did repel slugs ("deterred feeding"), but it did not kill them outright.

Another useful bit of information is that caffeine eventually becomes toxic to coffee plants, as the caffeine leached from their fallen leaves, berries, and branches builds up in the soil. So be careful about using brewed coffee as a soil drench.

Here is a link that might be useful: Slugging It Out with Caffeine

That was a very interesting article. I am forwarding it to the UCCE office here in Napa as non of the UC research mentions this. I would think an occasional dusting wouldn't hurt the plants and it would be wonderful to reduce the population with something beside Sluggo and my foot.

Penny

I'm not too big on using coffee grounds in my garden they crust up on the soil and make watering difficult. However I do use them in one bed the white spider lilies and the lilies never looked better.

I'm not convinced about their so-called repelling affect either. My Mom spreads them all around her kitchen because she thinks they repel ants. I still see ants in her kitchen. It is so disgusting and nasty to clean up. Well coffee grounds do repel something, ME

I mentioned this to Westelle the other day - about how I sprinkle coffee grounds (used) on the ground. I swear (and I know there isn't much caffeine left in the grounds once it is brewed) the snails are NOT eating my plants!!! I don't spread it real thick around the plants, just sprinkle handfuls where I know the snails usually can be found. It's Starbucks coffee...maybe that's the magic!!

I tried this. Got a couple of bags from starbucks, poured them into a shallow wooden box I use to move compost and soil around and mix. Spread the coffee grounds around and left some in the box. In a few days the grounds in the box were covered by snail trails. They just used the box as a short cut. Best way is to just keep going out at night and picking them. Got over 100 one night. A lot less problems since then.

I agree with Paul, the most worry free approach is to go out with a flashlight at night and collect slugs, snails and earwigs while they are doing their dastardly deads. If you are not squemish a pair of old scissors works good to curtail slimy crawlers careers. A pair of thin vinyl or rubber gloves works good for picking earwigs off of tender leaves. I give my earwigs a firm pinch and they no longer devour my dalhias. No worry about poisons effecting benaficial bugs you get the offender in the act. I notice a reduction by 75% the next night. A miners light strapped to your head makes two hands free for "de bugging".

Shar, I use a miner's light, too, but not for slug or earwig cutting. :P I can just see you out there at night with your scissorsÂhehehe I am out there collecting leaves for my caterpillarsÂhehehe

Paul, interesting how the snails weren't deterred by the coffee grounds. You'd think that the roughness would hurt their tender feet. Did they go around the grounds? Just wonderingÂ

For those who do use coffee or plan on it (I didn't know caffeine was such a 'killer' to snails and slugs) Diedrich's coffee has a lot more caffeine than StarbucksÂ

I, too, discovered the snail deterrence of coffee grounds by mistake. I decided one morning that the gardenias had taken more than their fair share of my spent grounds, so I poured them on the gerbera daisy I had in a pot. Snails had been feasting on it, ignoring the crushed eggshells and even snail bait I'd used to get rid of them. No more snails since I gave that gerbera its first cuppa joe!

When I put in my yard, I put down about 200 lbs of coffee grounds in the yard. I recently had to dig up a tree and after digging about 3 ft down to get the stump I found a total of about 10 slugs. The tree used to be terribly infested with slugs, and all my neighbors have problems with slugs. Other than my tree, I have seen a total of about 3 the last year in all my potted plants. I also put it in my potted plants. Whatever the argument is, for me it worked. I rarely see slugs in any of my plants.

Interesting thread! I had loads of snails last summer in my beds and all over my Canna containers. I used SB's coffee grinds and they have mostly disappeared. In fact, when I pulled my canna out of their containers, I found quite a bit of dead snails. Just my experience...

5 years ago someone on another web site said my bug problem sounded like snails & slugs on my basil.I should put out coffee grounds,I did, the old leave still look like a shot gun blasted them, but the new growth was fine, until I ate them.
I have tried a side by side test: basil 12" APART, ONE WITH USED COFFEE GROUNDS & ONE WITH NO MULCH & THE COFFEE ONE IS FINE. The other was eaten by something, snails.