How To Reuse Coffee Grounds In Your Garden

We are all trying to cut down on our waste, but if you are a big coffee drinker, those coffee grounds will probably make up a big chunk of what you throw away every day.

But, coffee grounds actually have a whole lot of uses once you have made your cup of joe. They can de-ice your path and dye paper or clothing brown, but it is in the garden where they really can help you out.

Reusing Coffee Grounds In The Garden

The waste from your cup of coffee would otherwise end up in landfill, and even though you may think that the space they take up is minimal, remember that approximately 95 million cups are drunk every single day. 

That is a lot of grounds, actually!

So, here is how to make use of them when it comes to crafting your green space and keeping it looking perfect…

Composting

Coffee grounds are classed as Green Compost Material, and add nitrogen to your heap as well as providing most of the nutrients needed. 

As long as you balance them out with some Brown Material, like newspaper and dry leaves, it will keep your compost pile well maintained and healthy. Just add any which is spare, but be sure to keep Green and Brown balanced.

As there is only around 2% nitrogen in there, coffee grounds won’t kill any grass.

Compost Coffee Grounds

Fertilising

This works in a slightly different way than adding it to your compost bin.

While it doesn’t automatically add nitrogen, used coffee grounds do add organic material to the soil, which improves drainage, water retention and aeration.

Its addition can boost microorganisms beneficial to plant growth. Just work it into the soil around your plants. You can also use leftover diluted coffee in this way.

Watch out if you are thinking of using unused coffee grounds, though. This will increase the acidity and alter pH levels which could spell disaster for your plants.

Used coffee grounds are actually neutral pH, so won’t affect acidity levels.

Plants such as geraniums, asparagus fern, Chinese mustard and Italian ryegrass hate acidity. It has also been shown to negatively affect the soil around some vegetables like broccoli, leek, radish, viola, and sunflower.

Acid-loving plants such as hydrangeas, rhododendrons, azaleas, lily of the valley, blueberries, carrots, hollies and radishes can see benefits, but can also find grounds too acidic if used improperly.

Gardening with coffee grounds flowers

Mulch

As mentioned, organisms in the ground slowly break down the coffee grounds, and they then add nitrogen to the soil and improve its overall structure. This can make hard, block soil into a softer compost over time.

Keep it to a thin layer, as anything too thick acts more like a barrier and will not let air or water through. This can be great if you are planting into poor quality soil and need it to improve before you prepare your new garden.

Attracting Good Bugs

By this, we mean earthworms. Working the coffee that bit deeper into the soil can help them come a bit closer to your plants, working on the soil around them which will be highly beneficial – and helps nature.

If you have a dedicated worm house, you can also use the grounds to feed them. A cup per week spread out daily is perfect – but too much will be overly-acidic for them. 

If you’re releasing them into the ground once ready, any coffee then in the soil will be even more attractive to them.

Coffee In Soil Attracts Worms

Slug & Snail Control

The bain of any gardeners life.

The idea is that they won’t go near soil with coffee grounds on, as it is abrasive. Caffeine can also affect them negatively, so they will avoid going onto it which could be vital if you are to protect bedding plants.

Researchers do say that it won’t always reliably stop the most determined munchers though, but it is certainly better than using slug pellets and is said to be more effective than eggshells. It can also stop cats from using your beds as a litter tray!

Pest Control

They can even keep bugs which you don’t want near your plants (or yourself) away. We all know that grounds smell very strong – imagine what that is like for a tiny fly!

But for this, you will have to burn them. Start with dry, used coffee grounds in a bowl or on a flat safe surface. Simply treat them like incense and burn them.

Not only will the smell repel the likes of wasps, but the smoke will also make them find shelter elsewhere as it is a sign of danger.

How To Dry Used Coffee Grounds

How To Dry & Store Used Coffee Grounds

Obviously, if you drink coffee daily, this could mean your garden getting swamped with used grounds.

Using them when they have dried again will also be easier, not just for gardening but also if you’re making body scrubs or candles.

To dry them, put a layer of coffee grounds (kept to about 2–3 inches deep to prevent mould) onto a baking sheet and put in the oven at 93°C for around half an hour.

Alternatively, line the baking tray with newspaper and put somewhere airy and warm to dry, ideally in outside in the sun if there is any. Change the newspaper and rotate the grounds daily.

After around 2-3 days, they should be fully dried. Keep an eye on the weather in case it is windy or raining. Don’t worry about animals getting into it – most won’t go near the smell.

To store them, use an airtight container, preferably glass. Place some newspaper on top before sealing to absorb any moisture which can make its way in.

Check on them every month; any blue or white spots mean mould so they need to be disposed of immediately. But if all done properly, they can actually be kept like this for 1-2 years!

How to reuse coffee grounds in garden

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