How To Use Coffee Grounds In The Garden?

Last update: 2021-09-20

Tired of having to empty your coffee grounds every morning? Coffee grounds are nutritious – which can help increase the fertility of the soil in your garden.

Thanks to their natural acidity and high levels of nutrients like potassium and nitrogen, coffee grounds are a great choice for nutrient-poor gardens or alkaline soils. There are various ways to use coffee grounds to do many other things in the garden.

Here is a guide on how to use coffee grounds in the garden:

Used As A Soil Supplement

Add Coffee To The Compost

The easiest way to use coffee grounds is to put them in a compost bin.

How To Use Coffee Grounds In The Garden?

Aside from delivering more organic matter, they work to accelerate the decomposition of compost. You can take advantage of this easily by pouring coffee grounds into your compost pile.

The two common types of compost materials are “green” manure and “brown” manure.

Coffee grounds are “green” manure.

If adding too many coffee grounds to a compost bin, it’s essential to neutralize them by increasing the amount of "brown" manure - bulky, dry materials like dead leaves, sawdust, corn husks, straw, newspaper, etc.

Add Coffee Grounds Directly To The Soil To Increase Acidity

How To Use Coffee Grounds In The Garden?

The pH of coffee grounds is around 5.1 – which is quite acidic compared to the need of most garden soils. However, it particularly suits those plants that prefer high acidic soil. For example, blueberries, cranberries, citrus fruits, camellia, gardenia, and rhododendron.

Simply sprinkle around 2 tablespoons of coffee grounds near the plant roots at the early stage of the growing season to increase the soil acidity.

How To Use Coffee Grounds In The Garden?

A fun fact is that some floral plants bloom in a different color if planted on high acidic soil.

A typical example is hydrangea plants – if adding a certain amount of coffee grounds around the plant root during the growing season, its flowers will be blue later.

Mix Coffee Grounds With Agriculture Lime

How To Use Coffee Grounds In The Garden?

As stated above, the natural acidity of coffee grounds may not be suitable for most garden soils.

To reduce acidity, an easy way is to mix it with ½ teaspoon of agricultural lime. In this way, you can directly add coffee grounds to the soil as a soil conditioner or a mulch.

To Add Nutrients To The Soil

High acidity is not the only benefit of coffee grounds. They also contain many essential nutrients that help plants grow healthy, such as:

  • Potassium
  • Magnesium
  • Nitrogen
  • Coffee grounds without high content:
  • Phosphorus
  • Calcium

So, if your garden lacks nutrients, then coffee grounds are a very good choice.

Used As A Fertilizer Solution For Plants

Not only can coffee grounds be added directly to the soil in your garden but also be used as a fertilizer solution.

Put around 2 tablespoons of coffee grounds in a water bucket. Store in a cool place (like in a garage) for 1-2 days. The resulting solution will be amber in color.

How To Use Coffee Grounds In The Garden?

Remove the coffee grounds and use this solution for watering the garden.

This solution has the same nutrients and acidity as regular coffee grounds, so avoid watering plants that don't require a lot of nitrogen, potassium, or don't like acids.

Other Purposes Of Use

Repel Harmful Pests

How To Use Coffee Grounds In The Garden?

Snails and slugs may gnaw your precious plants, but they don't like coffee grounds much.

It is believed that coffee grounds work because the caffeine in them is harmful to these pests.

Add around ½ teaspoon of coffee grounds around the tree base to protect them. If you're afraid of the increasing acidity of your soil, you can sprinkle coffee grounds in a circle far away from the plant stem.

Prevent Cats From Entering The Garden

Coffee grounds not only help repel pests but also can keep curious cats from your plants.

Use coffee as the way to prevent snails that I stated above – sprinkle around the plant stem to be protected.

Again, the impact of acidity on the soil is unavoidable, depending on how much coffee grounds you need to use. You can mix it with lime before adding it to the base of your plants or sprinkle a bit far away from the plant stem.

Used As Food For Worms

How To Use Coffee Grounds In The Garden?

If you are a worm feeder, this is a good chance to make use of coffee grounds – which is the favorite food of worms.

Rest assured to pour plenty of them into your worm pile or worm bin.

But make sure to create a balanced diet with coffee grounds for worms – it should be supplemented with pieces of vegetables and fruits, newspaper, and leaves.

Prevent Fungal Infections

Coffee grounds can prevent some fungi that damage plants.

A thin layer of coffee grounds can prevent Sclerotinia, Fusarium, and Pythium fungi from attacking plant roots.

Eggplants, tomatoes, and pepper plants are particularly susceptible to fungal infections, so coffee grounds are a good solution for them.


If you intend to add coffee grounds to your garden soil, remember to monthly test the soil pH level. That’s all for this guide on how to use coffee grounds in the garden. I hope that you have got more practical ways to reuse this nutritious ingredient.

Thanks for reading!

Harry Ramos
Harry Ramos

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