Never heard of this, but I like it if it works. Everywhere, there are plenty of coffee grounds and their addition to most soils would be a good thing, or neutral at worst. Another slug stopper is diatomacious earth, sprinkled around the vulnerable plants. In effect, this stuff is similar to tiny shards of glass-it simply forms a physical barrier. For your frequent summer rains though, near-daily replacement would be necessary.

+oM

I already add coffee grounds to my plants, compost and worm farm, but the tip is for using actual coffee. Brew a pot, let it cool so you don't scald your plants and then put it in a sprayer and spray the ground and plants. The coffee comes in contact with the slugs and snails and they die from the caffeine. As the presenter mentions, this can be an expensive control, especially if you drink higher quality coffees. But there are a few 'really cheap' coffee options in places like Dollar General and if it is just the caffeine that does the killing, then those should suffice? I would be concerned that the caffeine would also kill worms, but seeing as the grounds are favored for worm farms, I don't think that will be an issue. If anything, it should make the entire yard smell awesome for a short while.

Used coffee grounds have less alkaloids than unbrewed coffee, and that is what people normally use in their compost. Also, after 4 to 5 months, the alkaloids go bad, and stop working. Most compost sits around long enough that the benefits of the caffeine go away, and the organic nitrogen, calcium, and manganese is still good. Fresh coffee can have a pH of as low as 4, but the used coffee grounds from Starbucks has a reading around 6.2 to 6.3.

I tried this on snails and slugs. It seems to repel the larger ones and kill the smallest ones. I was not totally impressed with how it worked, but if you can sprinkle used coffee grounds around your plants, and these insects won't get up on the plants, that is still getting something done.

In the wintertime I save up my coffee grounds and put them in a bucket outside to dry, in the springtime I sprinkle(about 5mm thick) them around my plants and put a new layer of mulch over them. I've noticed less snails in my garden and my plants seem to like it. You don't want to use too much coffee grounds on the surface because it will act as a moisture barrier. Generally snails and slugs don't like uneven surfaces so a layer of coarse mulch is best.

Any brand will work and most Starbucks have bags of used coffee grounds by the door.

What's In Used Coffee Grounds?