I love gardening (‘obvs’ as my kids would say ) but I also love chocolate. These two glorious worlds collided for me the other day. I heard that Craig Sams, the man behind Green & Blacks Chocolate, also runs Carbon Gold, a company which supplies a wonder product for gardeners called biochar. If Craig also owned a gin distillery it would be the ultimate triple whammy for me. Anyway I digress…
Biochar apparently improves soil in a very natural way that’s good for the environment, and the impact it has on plants is reportedly spectacular.
I wanted to find out more as soil-related tasks are on my January ‘to do’ list. I’ll be mulching a few of my key beds later this month using a very thick layer of well-rotted manure. As Monty says it’s better to mulch some of your garden really well, with a thick layer, then to do the whole thing half-cocked. (I’ll blog about it when I do it). I’m also sorting out my compost heap, which is a bit of a disaster at the moment, thanks to some bindweed running wild in it!
So if there’s a soil improver miracle out there, I’m interested! Could biochar be what I’m looking for? Well, Craig Sams kindly agreed to answer a few of my questions about his business and biochar. And luckily for me, given how rubbish I am at all things scientific, he explained all the technical stuff very simply. Here’s what he told me. I began by asking how he got into it.
Why did you set up Carbon Gold?
I founded Carbon Gold in 2007 as an organic, peat-free alternative planting aid after my stint as chairman of the Soil Association. I heard about this thing called “biochar” invented by pre-Colombian tribes in the Amazon, hundreds of years ago. It was so effective at improving otherwise infertile soil in the area. People were still illegally digging it up and selling it to this day.
The efficacy and longevity were just too stunning to ignore. Frankly I was amazed no one had rediscovered it before.
What is Biochar?
Biochar is an extremely pure (high-carbon) form of charcoal. When added to soil it improves its structure, prevents compaction, increases aeration and water-holding capacity and improves something called cation exchange which essentially means more nutrients are available to plant roots.
Because of the way it’s made and the material it’s made from (i.e. wood) it has an open, honeycomb structure that acts as a refuge for beneficial microbiology, meaning cultures of symbiotic species can stay around plant roots without getting washed away in the rain.
How’s it made?
Take some wood, bake it at a high temperature in an oven that has absolutely no oxygen in it. You’ll get biochar.
What makes it so special?
Well, there are a fair few things: because it’s so high in carbon it doesn’t degrade so it’s a permanent improvement to soil health. Its high-carbon nature also means that it’s locking carbon in the soil where otherwise it would be released into the atmosphere if it had instead been burnt in a fire. In fact, one tonne of biochar in the ground is equivalent to three tonnes of CO2 permanently sequestered from the atmosphere.
Then there’s our specific biochar, which we pre-load with all the beneficial microbiology we can, seaweed and wormcasts. Our mix has been shown in third-party controlled trials and commercial trials alike to help reduce the severity of – and in some cases prevent entirely – a whole swathe of plant diseases including:
- Ash dieback (ash trees)
- Honey fungus (trees and woody shrubs)
- Root mat disease (tomato plants)
- Horse chestnut leaf miner (which is interesting because this is a pest rather than a disease)
- Drought
And a whole host of other things.
We think the reason it has such an impact on a huge range of pests and diseases is that it improves plant health and vigour, thus making it more resilient.
There’s tonnes more info on our site!
Many professional growers have used Biochar how has it helped them?
Well, there are quite a few cool examples I could give. For instance:
- An organic crop grower suffered no losses on newly established trees (which is unheard of)
- A golf course customer was able to reduce their fungicide usage by 100% thanks to our products preventing a common disease
- Stockholm replanted all of its street trees with biochar to astounding visual results
- The Aspire Zone in Qatar successfully transplanted scores of fully grown foreign trees and successfully established them into their hot, sandy soils using our products
These examples sound incredible, but I sadly don’t have an acre of fruit trees. How could an ordinary gardener like me use Carbon Gold’s biochar products for some of my every day tasks? To answer this, I gave Craig some of my top gardening jobs. He told me the Carbon Gold products (which all contain biochar) that he’d recommend and how to use them…
- Planting trees: Tree Soil Improver in the hole (use 1 part soil improver to 9 parts soil)
- Looking after trees: Tree Soil Improver as a top dressing covered with mulch (willow if you have it)
- Planting shrubs: Tree Soil Improver in the hole (use 1 part soil improver to 9 parts soil)
- Feeding roses: Soil Improver as a top dressing
- In tubs and containers : Carbon Gold All Purpose Compost
- Looking after lawns: Mow your lawn short, scarify and sweep Turf Improver into the holes, about 1kg per square metre
- Growing fruit and veg: All Purpose Compost. If you want mega fruit and veg, add some Biology Blend
- Planting bulbs: Plant in All Purpose Compost
- Sowing seeds in trays or direct into the ground: Seed Compost
Biochar – what next?
I don’t know about you, but I’m intrigued by this product. I like the idea of adding something natural to my garden and making a real long-term difference to my soil’s fertility – and doing something good for the environment. So I’m going to try it out.
I’ll definitely use it to feed my roses and in my containers. In an attempt to be all scientific I may do some trials with identically planted containers to try to gauge the difference it makes. So watch this space!
In the meantime, I may give some Biology Blend to my lovely neighbour, Desi, who grows a lot of fruit and veg. You never know, she may send some super-sized veg back my way as a thank you later in the year!
A big thank you to Craig Sams for answering all of my questions. You can find out much more about Carbon Gold, its product and biochar here
If you want more ‘green’ gardening ideas you may also like my blog on natural garden remedies.
What is the source of the “wood” in making the charcoal? Surely the trees were doing the job of absorbing CO2 without being made into charcoal, and making charcoal itself no doubt puts CO2 into the air.
Hi Glenys, that’s a perfectly reasonable question, I’m glad you asked. The charcoal is made from an invasive species similar to rhododendron something that is already being chopped down and cleared.
We are lucky to have you! I’d heard of this but I didn’t know about it’s use to reduce fungicides and ash die back, how interesting!
Thank you Hollie – it is really interesting isn’t it. I found the whole subject fascinating – and quite thought-provoking. Definitely going to test it out.