Onnu Biochar

Inoculated Biochar

£29.00 GBP

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Boost your soil’s health with our biochar enriched with beneficial microbes. This nutrient-rich blend enhances moisture retention, promotes root growth, and supports sustainable plant vitality—perfect for home gardens or commercial applications such as farming, horticulture or landscaping.

Size 20L Bag 40L Bag Bulk Bag (1.7 m3)

Quantity

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✅ EBC-Certified Biochar ✅
📦 Free Shipping on all 20L & 40L bags 📦
🌿 Peat Free 🌿

Biochar inoculated with our liquid Grow Microbes ™

Unlock the power of enriched biochar for exceptional soil health and plant vitality! Our Biochar inoculated with our liquid Grow Microbes ™ combines the remarkable properties of biochar with a carefully selected blend of microorganisms to create a high-impact soil amendment. The porous structure of biochar not only improves soil aeration and moisture retention but also provides an ideal habitat for beneficial microbes, offering them shelter and a stable supply of nutrients. This synergy creates a resilient, healthy microbial community that supports nutrient cycling, encourages robust root development, and fosters stronger, healthier plants.

Biochar’s vast surface area and moisture-retentive qualities make it a long-lasting, reliable home for microorganisms, allowing them to thrive and multiply in the soil. As these microbes break down organic matter, they steadily release essential nutrients in plant-accessible forms, effectively enhancing soil fertility over time. Biochar's carbon-rich composition also helps lock nutrients into the root zone, reducing nutrient loss and creating a nutrient-rich environment. Together, biochar and its microbial allies enrich soil health, support resilient plant growth, and reduce the need for added fertilisers—making this blend an ideal solution for sustainable, productive gardening and farming.

Our biochar is EBC-certified, ensuring our products are safe, effective, and environmentally responsible. You can find out more about what EBC-certification means here.

Want a full rundown on biochar, how it is made, it's benefits and sustainability credentials? Click here to find out more.

Key Features

Enhanced Soil Structure & Moisture Retention - Biochar’s unique porous structure helps retain water and improves soil aeration, ensuring plants have access to the water and oxygen they need.

Boosts Nutrient Availability - Beneficial microorganisms work in synergy with biochar to break down organic material, making essential nutrients more accessible to plants.

Promotes Root Health & Growth - By supporting a thriving microbial environment, enriched biochar strengthens roots, helping plants develop a robust foundation.

Reduces Fertiliser Needs - With improved nutrient retention and release, biochar-enriched soil requires less frequent fertilisation, making it an eco-friendly and cost-effective solution.

Application

Mixing Ratio: For best results, blend 10-20% of enriched biochar by volume with your soil or compost. This concentration provides the ideal balance to improve soil structure, enhance nutrient retention, and support both microbial activity and plant health without overwhelming the soil. The added microorganisms will thrive in this ratio, creating a healthy, balanced soil ecosystem.

Application Depth: Biochar with beneficial microorganisms is most effective when applied near the plant root zone, where it can immediately enhance root access to moisture, nutrients, and microbial support. For new plantings, blend the biochar directly into the planting hole at root depth. For established plants, apply as a top-dressing layer around the plant base. Regular watering and natural soil processes will gradually move the biochar into the root zone, allowing its benefits to reach the plants’ roots over time.

Root Zone Application: When applying enriched biochar around root areas, maintain a concentration of 10-20% by volume to provide an optimal environment for both roots and microbial communities to flourish.

Watering Guidance: After applying biochar with microorganisms, water the soil lightly to activate and integrate the biochar into the soil structure. This initial watering helps the biochar retain moisture and supports microbial activation, promoting immediate benefits to soil and plant health. Avoid overwatering, as excessive water can cause nutrient leaching, which could reduce the effectiveness of both the biochar and its microbial partners.

Postage and Packaging

Shipping is free on all 20L & 40L bag purchases. Bulk bags are shipped on a pallet costing £49.99 each.

We expect to send out orders within 3 business days of receiving them, and they should arrive within 5 business days from your order.

Delivered promptly

Delivered promptly. Product looked good. Spread on beds to counteract herbicide residue in compost so hoping and waiting to see results but looking good at this stage.

Excellent value

Of course only time will tell but this certainly looks the part and seems good value.

Excited to see the outcomes!

Product was shipped and received on time. Will be using over the weekend and excited to see how the inoculated biochar performs compared to other products I have used in the past.

Bulk enquiries

Looking for more than 5 bulk bags? For larger orders in bulk bags or delivered loose, and to benefit from our volume discounts, visit our commodities business, Onnu Bioflow, or email info@onnubioflow.com.

Onnu Bioflow

Want to trial biochar?

Running a trial? We can advise on how to set it up so you can measure the impact of the biochar. Contact us for more information!

Biochar

Factsheet

Our factsheet is a comprehensive guide for biochar and how it works. With summaries, glossaries, property tables, product descriptions and application rates, this fully-referenced factsheet can help you familiarise yourself with the world of biochar.

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Additional

Services

Biochar Implementation Plan

A tailored strategy to integrate biochar into your soil management and growing practices.

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Biochar Trial Support

Personalised consultations to address your unique soil challenges and goals.

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Biochar Bespoke Blends

We can make a bespoke product to match your precise requirements.

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Biochar Sieving

Whether you need fine biochar, or larger particles, our sieving service ensures consistency and quality in every bag you receive.

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Excellent stuff

We lost our garden to invasive bamboo someone had planted 20 years ago so had to renovate the whole thing including taking out 2 ft of soil. We put in new topsoil with Onnu biochar under the new lawn and this Onnu compost throughout the new beds and the new plants (and the lawn) have gone stir crazy for it! Thank you for helping save our new (but very old) garden!

Great for Tomato Seeds

I used this for germinating tomato seeds indoors and it worked fantastically, all the seeds developed to seedlings and I have even had fruits from some already too!

The Grass is Greener

Tried a few composts before to try and bring my grass back to life with little to no impact, but the Biochar actually made a real difference. The soil is healthier, holds moisture better and my lawn is the envy of my neighbours Highly recommend it if you’ve been let down by other products.

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Inoculated Biochar