Coffee grounds for potager, yes or no?

I put them in my tomato beds this summer, with other fertilisers and new soil mix, so I can’t say if it’s useful for the bed or not. I do see plants are more productive. I will test them with the strawberries in pot, put in a few plants and not in others, to see if there are any real difference.

Do you use them for your vegetables and fruit trees? Yes or no according to your experience?

So I had a look at the scientific literature, and frankly I kicked myself. Coffeegrounds are of course a rich source of caffeine – in fact they can be richer than coffee itself, depending on brewing technique. One of the key functions of caffeine in the plants that produce it is allelopathy – the ability to reduce competition from surrounding species by suppressing their growth. Caffeine is packed into coffee seeds for the very function of suppressing the germination of other seeds.

There is a stack of studies to suggest it also stalls root growth in young plants, preventing their uptake of water and nutrients. Yet others have shown it has antibacterial effects (so much for boosting soil bacteria). And guess what? It isn’t even always very acidic. OK, its effects have varied widely depending on plant species, but it’s never shown colossal benefits that could outweigh the risks.

I just add it on top of the beds like mulch. I don’t put it around seedlings. As a child in Florida my neighbor put coffee grounds around his pansies which grew under a live oak. They flourished even in summer! (Pansies are generally only viable in the winter in much of Florida.)

I have a tumbler composter. I like that everything is contained in the tumbler but when it gets fullish it can be tough cranking the handle.
I started putting in coffee grounds in the early spring with some additional items, not a lot of scraps. I did also add some compost accelerator. I dumped it all out after a few months and it was lovely and black.
So I think the coffee grounds are good but should mellow a bit?

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I put them in my compost as well.

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“Food is a pretty good prism through which to view humanity.”

― Jonathan Gold