Biochar for Gardening: How to Use It + 4 Major Benefits


Wondering why you should use biochar for gardening and how to go about it?

Biochar is an eco-friendly soil amendment that helps add life to your garden. 

It helps the soil retain water and essential plant nutrients, even increasing its carbon content.  

The result?
You’ll be growing healthier and happier plants! 

In this article, we’ll discuss biochar and its four major benefits for your garden. We’ll also cover the best way to use biochar for gardening and answer three related FAQs.

 Further reading

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Let’s get started!

What is Biochar?

Biochar is a black carbon compound that helps improve soil fertility and plant growth in your garden. 

It’s produced by pyrolysis, which involves burning biomass (organic matter like agricultural waste) at high temperatures in the absence of oxygen.  

Biochar is also known as bioactivated charcoal, and it’s similar to other carbon materials made via pyrolysis, like charcoal and activated carbon. 

However, biochar differs in its applications — especially as a soil amendment.

Biochar’s first recorded use as a soil amendment was discovered in “terra preta,” a highly fertile soil used in the Amazon basin over 2000 years ago. The fertile terra preta soils were mixed with poor soil to improve crop yield. 

So, how does this bioactivated charcoal actually help your garden?
Let’s find out. 

4 Major Benefits of Biochar for Gardening

Thanks to biochar’s fine-grained structure and other properties, this modern-day terra preta offers some important gardening benefits, such as: 

1. Increases Water Retention in Soil

When you add biochar to your garden soil, its porous structure increases the soil’s water-holding capacity.


Biochar’s pores draw water and hold it in, preventing it from escaping into the earth or running off out of your plant’s container. The water is then given to the plants as needed, reducing the soil’s water requirements and increasing its drought tolerance.

This is especially useful for soils with poor water retention capabilities, like silt and sandy soil. 

So if your garden has sandy soil, you can use biochar to easily increase the water available for your plants. 

2. Boosts Your Garden Soil’s Health

Here’s how biochar improves soil health:

  • It enhances soil fertility by increasing the water and nutrient retention capacity.
  • It improves soil structure by decreasing soil compaction (the lack of space between soil particles) and improving aeration. 
  • It facilitates the growth of soil microorganisms or beneficial bacteria responsible for breaking down soil nutrients from organic matter.
  • It increases the soil’s cation exchange capacity (the ability to retain and supply nutrients to plants).
  • Biochar’s alkaline nature helps reduce soil acidity (increases soil pH), improving the soil quality in acidic soils.  

As a result, your garden soil becomes more suitable for plant growth.

3. Improves Plant Health

We’ve mentioned how biochar improves aeration and overall soil structure. 

This helps plant roots grow deeper into the soil, giving them better physical support and increased access to nutrients. 

But that’s not all. 

Studies have found that biochar can suppress diseases in certain plants, like tomato, pepper, strawberry, and asparagus. As a result, plants grown in biochar amended soils have better disease resistance, and naturally, better health. 

4. Facilitates Carbon Sequestration

Biochar’s ability to sequester carbon lets it capture atmospheric carbon dioxide — a major greenhouse gas. 

How does this help your garden?

When biochar captures carbon dioxide, it stores the greenhouse gas as stable carbon (carbon sink) in the soil for thousands of years, where it helps restore degraded soils and improve soil productivity. 

And as this also reduces greenhouse gas emissions, it helps reverse the effects of global warming, like the decline in soil moisture content and crop yield

This means that you help your plants and the environment by using biochar for gardening.  

Let’s now explore how you can use biochar for gardening.

How to Use Biochar in Your Garden 

There are two important steps for using biochar in your garden:

Step 1: Activating Biochar

When added to soil, raw biochar acts like a magnet — temporarily drawing surrounding nutrients and water. This can slow down plant and soil productivity for a short period before contributing to improved plant yields. 

To avoid this period of unproductivity, biochar needs to be activated (charged with nutrients and microbes) by mixing with nutrient-rich biomass before it’s added to the soil.

Here’s how you can activate biochar:

  • Create a 50-50 mix of biochar and organic material, like compost, mulch made of plant material, or natural fertilizer, and leave it aside for 10-14 days.
  • Or, soak raw biochar in liquids like compost tea (water from soaked compost) that are high in nutrients and microbes.

Activating biochar loads it with nutrients, water, and beneficial soil microbes that support soil fertility and promote plant nutrient availability and plant growth.

Sounds like a lot of work?
Well, you can skip the activation process with the eco-friendly, pre-activated potting mix from Rosy Biochar.

Rosy Biochar

Rosy produces the most convenient and sustainable biochar, made from soft pine wood waste that would otherwise have ended up in landfills. 

It’s a clean, single-source product without added fillers or chemical fertilizers. 

Whether you’re an indoor plant parent or a backyard gardener, you can save time and see your plants thrive using the pre-activated Rosy Potting Mix — which consists of fine biochar, plant-based compost, and beneficial endomycorrhizal fungi.

Just apply the Potting Mix to your garden soil or the base of an existing plant, and it will be thriving in no time.

Grab a bag of Rosy to get started right away!

Step 2: Applying it to Garden Soil

Remember, you can use biochar to revitalize poor soil or supplement healthy soil. 

You simply need to know where and how much to apply.

Depending on your needs, here are some ways you can apply this organic material to your garden:

  • On the soil surface: You can sprinkle activated biochar over your garden’s soil surface. Alternatively, you can add 2 cups of Rosy directly to the base of each plant.
  • Mix it into the soil: You can work the activated biochar into the top four to six inches of the soil. This method is great if you’re yet to place your plants in the garden.
  • Transferring pots to gardens: You can use biochar amended soil when transplanting plants from pots to a garden bed. Here, you can mix compost (or other organic matter) with 20% biochar and apply it to the garden soil where you’ll set the plant.

Read our in-depth guide on how to use biochar properly for more information.

Now, let’s look at some FAQs about biochar. 

3 FAQs on Biochar 

We’ll answer three frequently asked questions about biochar for gardening:

1. Is Biochar a Fertilizer?

No, biochar isn’t a fertilizer. 
But it helps reduce the need for chemical fertilizer application.


Biochar improves soil fertility, leading to better soil water and nutrient retention. It also promotes the growth of beneficial soil microbes that increase plant nutrient availability.

As a result, biochar amended soils require less fertilizer application. 

Why is this important?
Reduced usage of chemical fertilizer helps prevent water contamination and changes in soil pH, making your garden a healthier place for plants and soil microorganisms.

Moreover, chemical fertilizers have a high carbon footprint!
By using biochar, you’re actually offsetting your impact on climate change.

2. Is Barbecue Charcoal a Replacement for Biochar?

Although biochar is a form of charcoal, you can’t replace it with other charcoal forms like barbecue charcoal.

Here’s why:

Biochar is produced from pyrolyzed wood or plant material at high temperatures and can be used for gardening and agriculture, water filtration, etc.

On the other hand, barbecue charcoal briquettes are produced through pyrolysis at lower temperatures (similar to wood ash), giving it a smaller surface area than biochar. So, it doesn’t have the same potential for nutrient and water retention.

Barbeque charcoal briquettes may also have ingredients or contaminants (like tar, resins, and harmful chemicals) that negatively impact soil biology — unlike biochar.  

3. Is Biochar Better Than Compost?

Both compost and biochar are useful for gardening, and neither can replace the other.

Biochar’s porous structure and large surface area help retain soil nutrients and water, making it a valuable soil amendment. It also improves soil quality by increasing the soil carbon content.

On the flip side, compost is valuable for its nutrients and beneficial soil bacteria or microbes. It’s especially useful in increasing the soil’s nitrogen content.

But you don’t have to choose between them.

When biochar is used with compost (or activated with it), it greatly improves plant growth and soil health. And studies have shown that together they increase the nutrient availability of nitrogen, phosphorus, and potassium in soils.

Wrapping Up

Clearly, biochar can do wonders for your garden (and the environment). 
It’s the most sustainable garden and soil additive any organic gardener could use today!

When it comes to biochar for gardening, you need the best product available today. You need Rosy.  

Pick up a bag of Rosy’s Potting Mix to discover what a healthy and happy garden looks like!