Four big bags of coffee grounds.

Starbucks gave us worms.  Indirectly.  What Starbucks actually gave us was used coffee grounds, and putting used coffee grounds in the soil is an excellent way of building up your worm population.

Sherry read on a website that Starbucks gives away their used coffee grounds.  (What else could they  do with them – sell them to China?  Throw them out with the trash is probably their only other option.)  So as we were having our “tall, no fat, no foam latte and buttered croissant”, we asked.  Sure enough, we could have anything they had on hand, which on this day was four big plastic bags.  It took two of us to carry them to the car.

We asked if many people took advantage of this offer.  Not too many.  In the spring, more people ask about it, and a few on into the summer, but during the rest of the year, not many.

Although there is online literature about coffee grounds and worm populations, we discovered it by accident.  You know about our clay soil!   Well, we knew that coffee grounds could be used as an addition to mulch, so we began to casually toss our coffee grounds into one area of the yard that we weren’t going to get to for a while.

Well, when we did get to it, the area was filled with earthworms.  Huge earthworms.  I would bet that they were 30% bigger than the earthworms elsewhere in the yard.  And when you picked one up…. you could see that they had been doing a lot of coffee because they just squirmed like crazy.

By the way, just tossing the morning coffee grounds onto the ground won’t raise the ph considerably, so you don’t have to worry about the soil becoming too acidic.  Large amounts, like the four bags we got, should be worked in and spread around.  We usually have several composting areas going, and often have a pile of dirt, clay or/and debris somewhere, so we can use a lot of coffee grounds.   And in a compost pile, the acidity is broken down and made more neutral, so it won’t make the completed compost noticeably more acidic either.  Used coffee grounds, FYI, contain in the neighborhood of 2% nitrogen, so think of them as grass clippings.

AND, as if all that weren’t enough, caffeine has a negative effect on slugs.  It slows their digestive system.  Now, you probably won’t get its full effect, since it takes about a 2% solution to actually kill the little buggers (and your cup o’ joe is less than 1/2 of a per cent), but any amount of caffeine will have at least a retarding effect, and may chase them into your neighbors yards.   Our experience is that slugs and snails don’t like rough textures, like broken up egg shells, so it stands to reason that the rough texture of coffee grounds on the ground would irritate them as well.

Here are a couple of pertinent websites:

How To Do Things

Science Daily

And how’s this for a coffee/worm compost bin:

A Dunkin Donuts worm bin in Florida, powered by coffee.

For the story, go to http://realneo.us/content/dunkin-donuts-have-some-worm-tea

Filed under: Soil Amendment