The Short Guide to Watering Plants with Coffee. Do’s and Don’ts

About 165 million bags of coffee were consumed globally in 2019. Although coffee is loved by many, most people still do not know that it is not only good for the body but also plants.

Coffee grounds can be used as fertilizer when mixed with other organic matter. It creates some nourishing soil that is good for your plant’s healthy growth and sturdy stem.

Brewed coffee also contains potassium and magnesium, which are essential for the growth of plants.

? Article as a part of a series of articles “Watering plants with X-ingredient”. You can also read: watering plants with milk, watering plants with sugar water.

Can You Water Plants with Coffee?

After enjoying your favorite cup of coffee, you may be wondering what to do with the leftovers. Depending on the plants you have at your place, you can use the leftovers to water the plants.

Why not have a watering plants with coffee experiment Ensure you dilute your coffee well before you use it as fertilizer. For example, you can have ¼ coffee and ¾ water in your mixture. Coffee fertilizer can be used for both indoor and outdoor plants.

Coffee grounds are composed of two per cent nitrogen, which is a very vital component for the growth of plants. The composting fields present microorganisms that break down, releases nitrogen and aids in killing weeds and pathogens in the process.

How to Water Plants with Coffee

Diluting your coffee to use as plant fertilizer should be done in consideration with the pH factor. The pH of coffee ranges between 5.2 to 6.9 depending on the type and how it is prepared. Coffee is generally acidic due to its low pH level.

Most plants grow well in slightly acidic 5.8PH to 7. Tap water has a pH value greater than 7; therefore, using diluted coffee can increase the acidity of the soil. Allowing leaves to decompose on soil surfaces can help decrease soil pH levels.

Liquid coffee can also be used to water a compost pile that has become too dry.

Symptoms of Excess Acidity to the Soil

Growing plants with coffee will require your attention for any signs of too much acid in the soil. Plants will start to turn yellow or brown at the edges and die. Therefore, you should water down the coffee before you use the mixture.

Acid Loving Plants

Not all plants will respond well when you water them with coffee. The acid-loving plants include:

  • African violets;
  • Norfolk Island Pines;
  • Phalaenopsis orchids.

You also need coffee water for plants like azaleas, pine trees, shrubs, rhododendrons, Siberian iris and lupine.

Sprinkling Coffee Grounds

Besides raising the level of soil acidity for acid-loving plants, sprinkling grounds into your plant’s soil can prevent snails and slugs from invading your garden.

Other uses of coffee grounds include keeping pesky animals such as cats or rabbits away, helping in aeration and water retention.

Do’s and Don’ts while Watering Plants with Coffee

So how should you approach your plants with coffee?


  • Use on both indoor and outdoor plants;
  • Find out whether the plants like brewed or ground coffee;
  • Dilute the coffee appropriately to add enough fertilizer for bushier, healthier plants.


  • Water plants that do not like acidic soil;
  • Water every time with the diluted coffee fertilizer to avoid yellowing of leaves.

Do you want to know more about exactly how to plants care properly — and still you home garden health? Check out our How to Water Plants guide and Self-Watering devices.