Forum home Fruit & veg

Pros & cons of using Coffee grinds?

I have been saving up coffee grinds to add to a compost bin for top dressing blueberries but I have recently read somewhere online that coffee grinds still retain traces of caffeine that suppresses growth in plants. The plants in the wild use this as a defence mechanism to stop other plants encroaching on their patch. Anyone else read this & should I be wary of using Coffee grinds in my compost?


  • pansyfacepansyface Posts: 21,891
    You win some, you lose some, maybe. See below.

    I would ‘t worry too much about it. The rotting action in the heap will probably destroy the caffeine anyway.

    Apophthegm -  a big word for a small thought.
    If you live in Derbyshire, as I do.
  • josusa47josusa47 Posts: 3,530
    Coffee grounds spread on the soil surface around vulnerable plants are said to deter slugs.  I don't how rigorously this has been tested, but I tried it last year, with grounds donated by a friendly local cafe, and it seemed to work.
  • FireFire Posts: 17,116
    I would just compost them.
  • HouseFinchHouseFinch Posts: 327
    We have just planted a hedge of 29 this year (our first house). So far the whole beans and grounds that we collected from local coffee shops has not hindered the growth, and they were applied directly as mulch early this spring. If they get plenty of water, I suspect any remaining caffeine gets diluted and washed away-or our worms suck them dry.

    I used them because they were supposed to acidify the soil, then found from various sources they don't, went into a blind panic and applied more fast acting soil acidifier.

    We have also mulched over top with our Christmas tree needles and peat moss. My OH throws on some grass clippings when he does the lawn. So far they are doing quite well-aside from the one at the end. Even it has buds along the its bare stalks.

    Lots of berries that I still need to net off before the various local birds congregate.
  • My mum has always used it in compost and never had any issues with slowed growth...quite the opposite!

    A few weeks back I noticed the leaves of one of my strawberry plants were going yellow and it was massively behind the other in terms of had stopped opening and this not been pollinated...I added coffee grounds for a "hit" of nitrogen and they did the trick quite nicely! I've sence put in some manure and they're now lushously green again, but the coffee definitely did the trick and itsnow almost caught up in terms of overall plant size.
  • Valley GardenerValley Gardener Posts: 2,727
    I've been putting them on the garden for the last 18 months,and they have definitely improved my clay/stoney soil,making it lighter in weight,the worms love it too,so that has to be good.

    The whole truth is an instrument that can only be played by an expert.
  • Some helpful comments. I was under the impression from what I'd read that coffee grounds were acidic which was why I was putting them on my blueberries but if that isn't the case then I shall have to use something else.
Sign In or Register to comment.