Biochar Frequently Asked Questions
Find answers about choosing biochar, using it in soil or manufactured products, and planning your order.
Biochar basics
What is biochar, and how is it made?
Biochar is a carbon-rich material made by heating biomass, such as wood waste, with limited oxygen. This controlled process, called pyrolysis, creates a stable, porous material that can help soil retain water and nutrients and support beneficial microorganisms. It differs from ordinary open burning, which consumes much of the material. Learn what biochar is and how it works.
Can I use grilling charcoal instead of biochar?
Use biochar made for soil applications rather than grilling charcoal or briquettes. Cooking fuels may contain binders, ignition aids, or other additives that do not belong in soil. Appearance alone does not tell you whether a carbon material is suitable for your garden. Read about charcoal and biochar for soil use.
Does biochar replace compost or fertilizer?
No. Biochar helps retain nutrients supplied by soil, compost, and fertilizer; pure wood-based biochar is not a major nitrogen source or a complete fertilizer. Compost adds organic matter and nutrients, while biochar provides a lasting porous structure.
Compost-containing blends contribute nutrients, and CarbonBoost™ supports soil biology, but plants still need appropriate feeding. Continue fertilizing vegetables and herbs as needed; feed cactus and succulents according to their needs and growing season. For lawns and landscapes, follow the site’s soil and maintenance plan. Learn how biochar supports plant nutrition.
What are biochar’s environmental benefits, and is it carbon negative?
Biochar can turn suitable biomass residues into a useful material, store carbon in a stable form, and support soil water and nutrient management. Whether a particular production-and-use system is carbon negative depends on whether it stores more carbon than it releases. That conclusion requires considering the full system, rather than assuming every biochar product or application has the same carbon outcome.
Choosing a product
How do I choose a Wakefield biochar product?
Start with what you are growing or making. Garden products include pure biochar amendments and blends with their own mixing directions. For land, soil production, or industrial use, consider ingredient composition, particle size, moisture, quantity, and handling needs. Browse Wakefield products or compare the options, then use the relevant bulk or industrial page for application-specific help.
Which biochar should I use in a manufactured soil blend?
Start with Premium Biochar for most potting soils, growing media, and controlled formulations. Biochar AG is an economical alternative where its higher ash content fits the blend. Choose Premium Biochar LM™ when incoming moisture needs to be limited: LM is dry, while standard Premium Biochar is supplied moist and can suit processes such as wet mixing. Explore biochar for soil manufacturing.
When should I choose LM or micronized CarbonMicro® 50?
Both Premium Biochar LM and CarbonMicro 50 are dry, low-moisture biochar ingredients. LM provides coarser material for direct blending or further processing; CM50 is a micronized powder for formulations requiring finer particles. Industrial use does not automatically require micronized biochar. Choose around your equipment, particle-size requirements, and finished product, including any further processing or densification you plan. Compare Premium Biochar LM and CarbonMicro 50.
How is Biochar with CarbonBoost different from Premium Biochar?
Biochar with CarbonBoost combines Premium Biochar with humic acid, mycorrhizae, and beneficial bacteria for added support for soil biology. Choose Premium Biochar for a pure biochar amendment, or CarbonBoost when you want those additions included. Both use about 5–10% by volume of the finished soil mix. Explore Biochar with CarbonBoost.
Which Wakefield products are OMRI listed?
Premium Biochar and Biochar AG are covered by the OMRI listing named Wakefield Biochar Soil Conditioner. Ask Wakefield for the documentation your project requires. Individual ingredient listings do not make every finished blend OMRI listed. Ask Wakefield about documentation before specifying Premium Biochar LM.
Gardens & containers
How much Premium Biochar or Biochar with CarbonBoost should I use?
Aim for about 5–10% by volume of the finished soil mix. Mix thoroughly into existing soil or your growing mix. For example, one scoop of biochar plus nine scoops of soil makes a mix containing 10% biochar by volume. Use the Biochar Calculator for a package estimate. Pro Garden Mix™ and the specialty blends have different directions; see their questions below.
Do I need to charge or prepare biochar before using it in soil?
Premium Biochar: For new plantings, an optional preparation step is to mix it with mature compost and keep the mixture moist for about one to two weeks before incorporating it into soil. Incorporate near roots at planting or repotting; see the established-plant guidance below.
CarbonBoost and finished blends: Biochar with CarbonBoost, Pro Garden Mix, Tomato & Vegetable Blend, and Cactus & Succulents Blend need no additional charging. Follow each product’s mixing directions and water in. The optional preparation period for pure Premium is not a waiting requirement for these products. Read about preparing pure biochar with compost.
What do charged, inoculated, and ready to use mean?
Charged means enriched with nutrients, often through compost. Inoculated means beneficial organisms have been added. Biochar with CarbonBoost contains added beneficial microbes, including bacteria and mycorrhizal fungi; no additional charging needed. Pro Garden Mix has added mycorrhizal fungi, without CarbonBoost. Ready to use means follow that product’s directions without extra charging; it does not always mean use it alone. None of these terms means industrial activated carbon.
Do I need to add biochar every year?
For Premium Biochar and Premium Biochar with CarbonBoost, an annual application is generally unnecessary if amended soil remains largely in place. Compost or other amendments may be sufficient. Consider replenishment when substantial amended soil is removed, replaced, eroded, or moved away from roots. Keep the total at about 5–10% by volume of the finished soil mix; this is not an extra dose each year. For Pro Garden Mix and specialty blends, follow their product-specific mixing directions.
How should I use Pro Garden Mix?
Mix equal parts Pro Garden Mix and garden soil, raised-bed soil, or potting soil by volume. One scoop of each makes a 50/50 mix, so Pro Garden Mix makes up half of the finished soil mix. Do not use it as standalone potting soil. No additional charging is needed. See Pro Garden Mix product details.
Can I add biochar around plants that are already growing?
The best time to incorporate biochar is planting or repotting. Around established plants, gently blend it into accessible soil without damaging roots; surface spreading does not reliably move biochar into the root zone. For established containers, repotting is usually the most practical option. Consult a qualified arborist before working around dense tree roots.
How should I use Tomato & Vegetable Blend?
In containers, use Tomato & Vegetable Blend straight as a potting mix or mix equal parts blend and potting soil by volume. In garden beds and raised beds, mix equal parts blend and existing soil. One scoop of each makes a 50/50 mix. No additional charging is needed. It also suits peppers, cucumbers, beans, leafy greens, herbs, and other edible garden plants. See Tomato & Vegetable Blend details.
How should I use Cactus & Succulents Blend?
Use Cactus & Succulents Blend straight as a potting mix or mix equal parts blend and existing cactus or succulent potting soil by volume. No additional charging is needed. Coarse sand and pumice help maintain drainage and air space, while biochar supports soil structure and nutrient retention. See Cactus & Succulents Blend details.
How quickly will I notice results from biochar?
Biochar begins interacting with water, nutrients, and soil life after it is mixed and watered in. Visible changes take time and vary with soil, plants, weather, and garden care. It is used for lasting soil improvement, season after season, rather than a quick fertilizer response.
Can biochar burn plants?
Wood-based biochar used as directed is a soil conditioner, rather than a concentrated fertilizer that supplies a strong dose of soluble nutrients. Product choice and mixing directions still matter; do not treat this as permission to use unlimited amounts. Follow the directions for your specific product and continue normal plant care.
Can I use biochar with worms or worm castings?
Biochar can be mixed with worm castings as a soil amendment. That does not establish Wakefield products as bedding or feed for worms or other animals. For raising worms or other animal-care uses, consult a qualified specialist.
Does biochar affect soil pH?
Biochar can raise soil pH, but the effect depends on the product, amount, and starting soil. Even a 5–10% mix does not guarantee unchanged pH. For alkaline soil or acid-loving plants, check soil pH and ask a knowledgeable local gardening adviser about suitability. Biochar is not a universal pH balancer. Learn how biochar can affect soil pH.
How does biochar help tomatoes and other garden plants?
Biochar can help the root zone retain moisture and nutrients while supporting soil structure and air space. Those benefits can support tomatoes and other garden plants, but biochar does not replace watering, sunlight, or appropriate nutrition. Use the directions for your chosen product; pure biochar and finished blends have different mixing rates. Read about biochar and tomato growing.
Farms, landscapes & soil blends
How much Biochar AG should I apply per acre?
Plan on approximately 5–9 tons of Biochar AG per acre, depending on soil conditions and project goals. This is the material’s weight as delivered, including its typical 50–60% moisture content. Review agriculture application and planning guidance. Treat this as general planning guidance, not a site-specific prescription. Have a qualified local agronomist assess your soil and crop needs before selecting a rate. Tons here are US short tons.
When and how should Biochar AG be applied?
Work Biochar AG into the soil before planting when your field schedule allows. Incorporation brings it into contact with root-zone soil. Use professional-grade farm spreading equipment; small handheld lawn-and-garden spreaders are generally unsuitable.
The supplied moisture helps reduce dust during handling and spreading, and additional water is typically unnecessary before field application. Include your spreader type when requesting a quote so Wakefield can discuss handling considerations. See Biochar AG product details.
Can biochar reduce irrigation needs?
Biochar can improve water holding and help a site use irrigation more efficiently. The amount saved depends on soil, blend rate, depth, climate, and maintenance. Continue watering according to the needs of your plants or turf. Explore biochar for landscaping and turf.
How do I add biochar to an existing lawn or landscape?
For existing home lawns, use Premium Biochar or Biochar with CarbonBoost. Aerate, spread by hand or shovel, and rake into the openings for the preferred approach. Spreading and raking without aerating is another option. Small garden spreaders can clog with the pre-moistened material. Incorporating before seed or sod is the best opportunity.
In planting areas, gently incorporate into accessible soil without damaging roots. For established trees or site-specific soil advice, consult a qualified local professional. See landscape and turf guidance.
How much biochar should landscape soil or a manufactured soil mix contain?
About 5–10% biochar by volume of the finished soil mix is a practical starting point. For manufactured soils, adjust around your other ingredients and intended growing conditions. Engineered root zones and existing landscape sites may need a different approach. These volume guidelines are separate from the Biochar AG field rate and the mixing directions for finished garden blends.
How do I calculate biochar content in a concentrated amendment?
Calculate backward from the amendment’s share of the finished soil mix. If the amendment makes up 20% of the finished mix and your target is 5% biochar, the amendment should contain 25% biochar: 20% × 25% = 5%. All percentages are by volume. Discuss a soil-manufacturing application.
Industrial applications
Can biochar replace carbon black or other formulation ingredients?
CarbonMicro 50 can replace a portion of carbon black in some formulations. Biochar can also replace portions of certain fillers or carbon ingredients in other materials. The suitable replacement level depends on the ingredient’s role, formulation, processing conditions, and finished-product requirements. Formulation testing establishes the proportion and any processing adjustments. Explore carbon black replacement or materials and manufacturing applications.
How much biochar should we add to concrete or asphalt?
There is no single addition rate for concrete or asphalt. The amount depends on whether biochar serves as an additive, filler, or replacement for another ingredient, along with the mix design and required performance. Establish the appropriate loading through formulation testing. Explore concrete and asphalt applications.
Are Wakefield’s biochar products activated carbon?
These products are biochar inputs. Low-moisture processing and micronizing do not make them activated carbon. If your medium needs activation, include that requirement in your application discussion. Discuss a filtration application.
Which biochar should we use for filtration, and will it need processing?
Choose LM when incoming moisture needs to be limited, Premium when your process accommodates moisture, or CM50 when the formulation requires micronized powder. Both LM and CM50 are low-moisture inputs.
Some systems can use unactivated biochar in a media blend; others require additional processing. Your target contaminant, filter design, and required service life determine the approach. Explore filtration product selection and testing. Suitability must be established through application-specific testing. Wakefield does not promise drinking-water suitability or contaminant removal for an untested filter.
Can biochar be reused after filtration or another application?
The next use depends on what the biochar contacted or captured. In filtration or other controlled systems, spent material may be suitable for regeneration or another use only when its condition and captured substances are understood. Do not assume used filter media is suitable for garden soil.
In soil, biochar’s long service life usually means leaving it in place, not collecting and reusing it. See when another soil application may be useful.
Buying & documentation
Research & education
How can Wakefield support a research or classroom project?
Wakefield can help match a product to your study requirements and assist with handling, ordering, and delivery. Study design, testing, and interpretation remain with your research team, including any additional characterization or processing the experiment requires. Discuss a research or classroom project.
Still have a question?
Contact Wakefield for help with products, applications, bulk needs, or technical questions.