A Beginner’s Step by Step Guide

If you’ve got a green thumb or want to start gardening, you may have heard about using ground coffee beans as a fertilizer for healthier plants.

After trying it myself, I’ve developed a comprehensive, step-by-step guide to creating compost with coffee grounds.

I’ll also discuss the benefits and other things to consider before starting this process since using coffee grounds may not be ideal for all home gardening situations and plant types.

The Concept of Adding Coffee Grounds Defined

The concept of adding coffee grounds and even used paper coffee filters as compost and fertilizer is both popular and effective because it introduces nitrogen, which aids in plant growth.

However, it’s important to remember that these benefits can only be reaped from certain types of plants and in the right amounts.

Plants That Will Benefit the Most From Coffee Grounds

Most plants have a pH level between 6.0 to 7.0, which is neutral to slightly acidic.

I’ve found that the following plants will benefit the most from using coffee grounds as compost:

• Azaleas
• Hydrangeas
• Rhododendrons
• Blueberries
• Tomatoes
• Asparagus
• Carrots
• Radishes
• Most other vegetable plants

These are mostly acid-loving plants that benefit from the soil’s pH level being under 7.0. Since coffee grounds are acidic in nature, this helps skew the pH level to be more acidic.

In my experience, alkaline-loving plants like daylilies, geranium, sedum, and aloe won’t respond well to coffee grounds unless you thoroughly wash them to decrease the acidity.

Adding Coffee Grounds to Indoor Plants

Indoor houseplants can also benefit from coffee grounds, although not all species.

Species like African violet, philodendron, gloxinia, monstera, peperomia, and croton will benefit. I recommend sprinkling a small amount before planting or using it in a liquid fertilizer.

On the other hand, I advise against using coffee grounds on species like aloe vera, pothos, and orchids. These don’t grow too well in acidic soil.

Can You Use Fresh Coffee Grounds?

While you can technically use fresh coffee grounds, do so with caution.

Fresh, unbrewed grounds are more acidic and retain most of the caffeine that you won’t find in used grounds.

Remember to never use fresh grounds on very young plants or seedlings. The high caffeine levels can slow down or stunt the plant growth.

How to Create Compost With Coffee Grounds

Now you know more about the benefits and proper plants to use coffee grounds on, it’s time to add them to your indoor or garden plants and help them grow faster!

1. Find a Spot for the Compost Bins

Before gathering any composting materials and spent grounds, make sure to pick a good spot to place your compost bins.

I suggest finding spots with adequate drainage and close to a water source, like a hose.

You also want to choose a spot that is not too hot or cold to ensure the compost is at its best quality.

Placing it outside your living space is also ideal, as it can smell.

2. Collect Brown and Green Materials

After you’ve picked your ideal spot, collect brown and green materials. Brown materials include wood chips, pine needles, dry leaves, and similar materials.

Green materials include kitchen scraps, fresh grass clippings, eggshells, coffee grounds, and other organic matter.

I recommend combining brown and green materials in a 3:1 or 4:1 ratio. This is the ideal organic material mixture for a compost pile.

3. Layer the Materials Separately

Properly combining the organic materials into a good mulch mix involves layering it properly.

I like to spread the compost around the base of the plants in a thin layer to retain moisture.

Mix more of the coffee grounds with other compost as you add more soil to prevent a hardened top layer/barrier from forming. This will improve water retention in the root zone.

4. Mix the Layers When Adding More

As you add more compost materials to your bin, I recommend adding brown and green materials to the soil in alternating layers. This will ensure a good mix no matter how you add.

Adding it in alternating layers will also ensure that your plants receive equal amounts of micronutrients when you add the mulch.

5. Harvest and Use the Finished Compost

When the compost has turned into a good mulch, you can harvest it from your bin and add it to the soil your plants will be growing in.

I’ve learned that properly layering and mixing carbon-rich materials will evenly and efficiently distribute micronutrients throughout the roots for optimal absorption and growth.

You can also add worms from your worm bin to the mulch. These vermicomposters will help with soil aeration and distribute micronutrients more evenly.

How Do Coffee Grounds Benefit Plants?

While the major benefit is helping to create a good mulch mix in composting, coffee grounds can also be used as fertilizer.

It Helps With Composting

Coffee grounds are a green material, which is great when used in a 3:1 or 4:1 ratio with brown materials. This creates a good mix that distributes nutrients and microorganisms.

Nitrogen is the main material that coffee grounds add to compost. This material is essential, as it’s one of the basic building blocks for most plants.

Coffee Grounds and Filters as a Green Compost Material

I’ve found you can use the coffee ground filters as a green compost material too! Add the filters to compost the same way you would with the grounds.

However, make sure that the filters are made from all-natural materials like paper or labeled as “unbleached.”

Mixing Coffee Grounds to Make Liquid Fertilizer

In addition to its use in composting, coffee grounds can be mixed into a liquid fertilizer to encourage more plant growth.

Mix 2 cups of coffee grounds with 5 gallons of water, then steep it overnight. When done, you can either use it as a foliar spray or add it when watering the soil.

It Helps Prevent Fungi, Bugs and Pests

Coffee grounds ward off bugs like wasps, fleas, and mosquitos, as well as pests like slugs and snails that will munch on your plants.

In addition, many non-pathogenic and harmless fungi, like Fusarium or Trichoderma, are found on coffee grounds, which deter pathogenic and harmful fungi from developing on the soil.

Additional Nutrients Coffee Grounds Can Provide for Plants

Coffee grounds are also rich in other beneficial minerals, like phosphorus, magnesium, calcium, zinc, copper, and potassium.

What to Consider Before Adding Coffee Grounds to a Garden

Before you start adding coffee grounds to your compost or fertilizer, consider these points.

Keep Pets Away From the Composting Area

If you have any inquisitive pets, consider adding a fence or barrier between the composting area and their usual play areas.

This is because cats and dogs can get sick if they accidentally ingest any of the coffee grounds.

If your dog or cat has accidentally ingested some of the compost, bring them to the vet for treatment as soon as possible.

It May Create a Tough Crust on the Ground

Unfortunately, I’ve found that adding too many coffee grounds to the top layer of soil creates a hard crust.

This crust will prevent water and fertilizer from reaching the plant’s roots.

Therefore, add only a light top layer or sprinkling, no more than 1/8 inch thick. This will help plant growth but won’t harden too much.

Too Much Can Cause Stunted Growth

Adding too many coffee grounds, especially fresh grounds, can stunt the growth of younger plants. The caffeine content in the grounds causes this growth stunting.

 

Other Guides from Planet Natural:

How to Build a Compost Pile: Complete Guide with 9 Methods

How to Compost at Home: Step by Step Guide for Beginners