I get a lot of questions here at Learn How To Garden from subscribers and viewers. I had an interesting one recently from Aidan that’s very timely .  Here’s Aidan’s question:

“Hi Mark,
I notice you mentioned using coffee grounds on the vegetable garden to protect from slugs, is this a legal practice as during a  search on the internet I came across this article”

What this question does bring to the forefront is just how confusing legislation  is as coffee grounds are a naturally occurring product that we can make good use of in our gardens and I think what I’d like to do is just explain what coffee grounds can be used for.

Coffee grounds and are now available from most coffee shops and as far as the coffee shops are concerned it’s a great way of recycling  one of their major problems which is what to do with all used  coffee grounds.

Coffee grounds contain Nitrogen (N) at about 2.25 to 3% Potash  (P)about 0.06% and Potassium (K) about 0.6% as well as the vital trace elements of Magnesium (Mg)  Sodium  (Na)

This means that we have a usable amounts of nutrients available for growing plants, the Potassium and  Potash and available straight away and the Nitrogen slowly released over a period of time.

Coffee grounds are best used within three weeks of being brewed if we are going to use them to get the maximum benefit from these nutrients , but after this they still have numerous uses.

They also very useful for incorporating into No Dig Beds and compost heaps remembering that although they are brown in colour they in fact are one of the green elements and help the compost heap to heat up and to break down.

They are slightly acidic only having PH of between 6.2 to 6.9 and can be used to mulch around acid loving plants  in the flower borders and blueberries positively love them.

They also have a positive effect on earthworms and are a great addition to wormeries.

Surprisingly they are perfect for growing Oyster mushrooms in so a real win /win as you can still add them to compost after

Now to slugs some people have a really positive results from scattering coffee grounds around very susceptible plants but because they have not been tested for use as a garden pesticide it is strictly illegal under European legislation for them to be used in this form.

Therefore my advice would be to use them by all means to increase fertility within your garden to improve the pH of acid loving plants and if by happenstances they seem to repel slugs then perhaps using coffee granules instead of slug pellets, and finding the caffeine in the coffee deters slugs, incidentally this is also why tea leaves work well as a deterrent, but remember to inform you authorities that this was never your intention!

I hope this clears up some of the points raised, and I will attach a link to the legislation for any of you who suffer from insomnia

Below is the link for the article:

Slugs beware EU pesticide Police