Home Houseplants How to Use Activated Charcoal for Plants

How to Use Activated Charcoal for Plants – GIY Plants

Gardener putting activated charcoal or horticultural charcoal around a plant in the garden.

Some of the links in this post are affiliate links. This means if you click on the link and purchase the item, I will receive an affiliate commission at no extra cost to you.

Activated charcoal, also known as activated carbon, offers several benefits when used in gardening and potting. Made from coconut shells, wood, or other carbon-rich materials, activated charcoal undergoes “activation” at high temperatures. The result is a highly porous material known for its exceptional adsorptive properties and large surface area, making it beneficial for plant care.

Understanding Activated Charcoal

Activated charcoal is made by heating carbon-rich materials to higher temperatures in a controlled environment. This process enlarges the pore size within the carbon and increases its overall surface area. Due to this porosity, activated charcoal can absorb impurities, excess water, and even certain gases.

Benefits of Using Activated Charcoal for Plants

The activated charcoal benefits for your garden or houseplants are manifold. One of its primary uses is to improve soil drainage. It creates air pockets in the soil, helping to prevent waterlogging, a common cause of root rot.

When added to pots without drainage holes, a layer of activated charcoal at the bottom can absorb excess water, safeguarding your plants’ roots. This protective layer can be beneficial when planting in pots without drainage.

In terrariums, activated charcoal absorbs excess moisture. It reduces the buildup of bacteria and fungus, ensuring a healthier environment for your plants. It also helps to neutralize odors.

Furthermore, the application of activated charcoal can detoxify garden soil. It can adsorb certain impurities, pesticides, and herbicides that would otherwise harm the plants. Orchid potting mixes use activated charcoal for this very reason.

How to Use Activated Charcoal for Plants

The usage of activated charcoal depends on your specific gardening needs. For general soil amendment, apply one pound of activated charcoal for every two square feet of garden soil. A layer of activated charcoal at the bottom is usually sufficient for pots and terrariums.

In the Garden

To improve your garden soil’s health and structure, evenly spread activated charcoal on the surface. Work it into the top one to two inches of soil. This application helps to increase soil porosity, improve drainage, and absorb impurities. Activated charcoal can be beneficial for sandy soils as it improves water retention while reducing nutrient leaching.

In Pots and Terrariums

Place a layer of activated charcoal chips at the bottom when using pots without drainage holes or creating a terrarium. This base layer serves as a protective barrier, absorbing excess water and preventing the buildup of harmful fungi or bacteria.

In Orchid Potting Mix

For orchid care, mix activated charcoal into the potting medium. Its adsorptive properties help keep the orchid roots healthy by neutralizing harmful compounds and improving water management.

Buying Activated Charcoal

You can buy activated charcoal from a variety of sources. Ensure you’re purchasing horticultural charcoal or activated carbon suitable for garden use.

Avoid using grill charcoal, as it may contain additional compounds harmful to plants. You can find activated charcoal in granular form, chips, or powder. Choose the type that best suits your application.

Safety of Activated Charcoal

Activated charcoal is safe to use for plants. It is inert, meaning it won’t react with other substances in the soil or harm your plants. It does not affect soil pH or introduce any harmful substances.

Activated Charcoal: A Renewable Resource

Activated charcoal is also a renewable resource, often made from coconut shells or other renewable sources. Its production helps to reduce carbon dioxide, a significant greenhouse gas, making it an eco-friendly choice for the conscious gardener.


Activated charcoal can absorb some nutrients and impurities, so ensure you regularly replenish your soil’s nutrient content with appropriate fertilizers or compost. Always follow the package instructions for the optimal application of activated charcoal. Remember, while it is helpful, activated charcoal needn’t replace good gardening practices.


Using activated charcoal for plants can enhance your gardening practice. From improving soil drainage and health to protecting plants in pots without drainage, the benefits of activated charcoal are varied and significant. So, why not boost your plants by adding activated charcoal to your gardening routine?

Join Us

Sign up to get all the latest gardening tips!