Makin' Hay

Or more accurately, straw.

What’s the difference, you ask? Well, straw is usually the by-product of a grain crop. In my case, this was winter rye. You might recall that grain crops are grasses, and rye is indeed a grass. It grew tall all winter, and then began to go to seed to produce that grain that makes such delicious bread. I didn’t grow it for the grain, though. I grew it for its stalk. The ‘straw.’

Ok, so what’s hay? Hay is not a by-product, but a product in itself. Hay is often a mix of legumes and grasses, such as alfalfa and wheat, and is used as a dry feed for livestock. This is not to be confused with silage, which is green hay that is compacted into bales and put up ‘wet’ in order to ferment and increase the nutrition, and then is fed to livestock. Confusing?

Rye straw piled up under the apple tree, waiting to be used as mulch

Technically, what I did was grow hay - a green crop of rye and clover (grass and legume) - but I didn’t use it to feed livestock, and I didn’t use it for people food. As I’ve mentioned, I grew it only for the straw.

Why would I do such a thing? In a word: Biomass.

Grain crops - grasses - grow a ton of biomass, both above and below the soil. The above-ground part of the plant can grow many feet in a very short time. I actually reduced the size of my plants several times, to prevent them from setting seed. The first time I chopped them (reducing them by about two feet), they were already five feet tall. Then they grew that same amount back again and I chopped them again a second time. After that, they were slower to grow again, but still put on several inches before I chopped them down the final time. It’s just in their DNA to grow tall. This produces a huge amount of biomass above the ground, which can be used in several different ways.

But grasses also grow an enormous amount of biomass underground. They have vast and complicated root systems, which have evolved to anchor them, and that tall growth, in windy conditions. Think about where grain grows best - flat prairies in the middle of the country, where the soils were formed by ancient lakes, and are loose but nutritious, and there are no mountains around to block the wind. The grain (and other prairie plants) needed to evolve to have very strong roots to support their growth.

a famous illustration of prairie plant roots by Heidi Natura c.1995

What does this underground biomass do? It takes the sugars (made by the plant in the process of photosynthesis) and pumps them into the soil, attracting the trillions of microscopic creatures - bacteria, fungi, protozoa, nematodes - to their roots, increasing the interactions between the plant and the life in the soil. This creates an ecosystem which is incredibly favorable to the plant, providing micro-manure for nutrient uptake, as well as allowing for shared resources between plants. When the above-ground biomass (that is, the actual plant) is removed, that whole underground ecosystem is just there waiting and ready for the next crop. The soil ecosystem has been vastly improved.

This is why cover crops are so valuable. They can provide food for us, food and habitat for insects, and biomass for use in the garden. That biomass is also of great use in the compost.

The compost pile in the chicken run, under the fig tree

As you can see, much of the material that I am not using as straw goes onto the pile in the chicken run. They like to eat the bits of things I throw there, such as the green leaves and stems of the clover, and they find all kinds of bugs to enjoy, too. After the chickens are done scratching around in it, it all rots down into a deeply nutritious soil that I add to my veg beds in the fall, thus completing the cycle.

This whole process is a fun one. A bit of work, yes - but any crop requires a bit of work in order to reap a lot of benefit. It’s taken me a week to remove the covers from the North Garden, separate out the straw, put the rest on the compost, and then plant summer crops. It’s good exercise, and it feels wonderful to bend and stretch and squat and sweat in the warm spring sun. Summer is on the way, and soon this space will be filled with good things to eat, like tomatoes and basil. And I can feel satisfied knowing that I’ve improved the conditions for those crops, and that I’ve made my own organic straw with which to mulch them.

Reader Question - Cover Crops

Did you know that you can email me directly if you go to the ‘contact me’ page on this website? I would absolutely LOVE to answer any question you have, and if I can’t answer it, I’ll be honest about that, too. It’s all too obvious that I am running out of things to write about. When I was taking Horticulture classes, I was always learning something new about gardening, or trying experiments out in the lab, and I had lots of information to share. Then I swerved briefly into more general science classes, which still had some good, relatable info. But now I’m fully into my upper division courses, which are all for my Environmental Studies degree and include boring things like data collection and carrying capacities and population control and clean energy. Well, they aren’t boring to me, but they certainly aren’t the focus of this blog, and aren’t as fun to read about as bugs and vegetables and flowers. So I really appreciate questions! They give me a chance to write about fun things and to question my knowledge and opinions of them and of course, that way we can all learn together, which is my favorite thing of all.

This morning I got a wonderful email from a reader named Jill, who lives not far from me: “ I sadly lost most of my garden due to the heatwave and an irrigation issue. I’m looking at cover crops and know nothing about the subject. Do you have any tips or links to places you buy the seeds from. Maybe some simple do’s and dont’s? “ Thank you Jill! Thank you for reading the blog and thank you for this question and thank you for your faith that I can answer it!

Buckwheat, a summer cover crop in warm climates

Cover crops can seem intimidating and confusing, so let’s start from the beginning. What is a cover crop? The simple answer is that a cover crop can be anything you want it to be. The Oxford Dictionary definition is “any crop grown for the protection and enrichment of the soil.” Farmers tend to use specific plants to satisfy specific requirements, which can be very important, especially if you want to grow without inputs i.e. chemical fertilizers. Some plants provide nitrogen, some phosphorus; others attract beneficial insects, and still others provide biomass for feeding animals. Some are grown during the summer, and some are grown during the winter. Some are grown after a specific cash crop, to replenish certain nutrients.

If you’re a farmer, and you’re making a living growing and selling your crops, you’re going to want to know a lot more details about cover crops and how they can be used to save you money. But if you’re a regular home gardener, your needs are different. You want something to improve the soil, attract beneficial insects, look pretty, and feed your compost pile when it’s done growing. Maybe you want to avoid buying soil amendments this year (they’re going to be hard to find, considering how many people are gardening for the first time). Maybe you don’t like the structure of your soil, and you want to improve its water-holding capacities. Maybe you like birds, and you want to feed insects that will in turn become food for the birds. These are all fine reasons to grow a cover crop.

The thing that is most important is that you have a living root in the ground at all times. Now, if you live in upstate NY, you know that eventually that root will likely die, and that’s the way it’s supposed to be, and maybe even you time a crop so that it winter-kills and you don’t have to cut it down yourself. If you live in California, however, you can grow different cover crops at different times of the year, year-round. Having a living root in the ground is what improves your soil. The plant harvests sunlight, makes sugars, and pumps those sugars down into the roots and into the soil. This attracts microbiota, tiny creatures that feed on the sugars that the plant provides. In turn, they poop, providing micro-manure to the soil, and they burrow, improving air flow to the roots, and they die, recycling nutrients, and they move a ton of soil, making it rich and crumbly and perfect. If there’s no root in the soil feeding the microbes, then they move on or die off (or become very, very sluggish, waiting for the next influx of food). It’s not the plant that is feeding the soil, it’s the animals that are feeding the soil - the bacteria, fungi, protozoa, and nematodes - the primary and secondary consumers. When you spread manure or compost on the soil, it doesn’t feed the plant - it feeds the soil life, which in turn form these associations with the plant roots and provide the nutrients the plant needs to thrive.

image credit: center for food safety

So if you look at it this way, any plant can be a cover crop. No matter what kind of plant it is, it is going to continuously pump sugars into the soil and feed soil life, therefore improving your growing medium.

However, some plants need a lot of nutrients. If you’re planning a summer garden full of squash or melons, for instance, you might want a high nutrient load in the soil before you plant them. Why not grow a crop that will also add specific nutrients to the soil? Here is a handy chart, provided by the Organic Growers School, to help you determine which crop you need at which time.

image credit: the Organic Growers School

Don’t worry too much about the seeding rate. I just spread it on thickly, and that does the trick.

I’ve grown many different specific cover crops, and I tend to stick to two - crimson clover in the winter, and buckwheat in the summer. Some years I don’t use them at all. Some years I plant them intercropped with other plants that I am using for food. Some years I grow them alone in specific beds. They’re both great, but both require cutting and removing before they set seed (at least here in CA), or else they will seed everywhere (which is not the worst thing in the word). I’ve also done several mixes, especially in summer, that combine many species to provide many different nutrients. This is actually proving to be best for the soil, generally. If a living root in the ground is good for the soil life, then a wide diversity of roots in the ground would naturally be even better. I’ve also grown winter wheat and oats, which provided me with the best variety of beneficial insects I’ve ever seen in my garden. Long grass is apparently second only to a pond for attracting wildlife, and we saw that firsthand.

Many seed houses sell cover crops, but the best place I’ve found is Walnut Creek Seeds in Walnut Creek, Ohio (I know, it’s a coincidence that my town is also named Walnut Creek). They’re super-friendly, the farmer (Dave Brandt) has pivoted his business from growing corn and soy to growing cover crops, and he is also involved in a lot of research with the NRCS to show how cover crops can save money for traditional farmers, improving crops, soil, water levels, and erosion. Their prices are incredibly reasonable. They also sell specific gardening mixes for the home grower. I’ve used both the summer and the winter mix, and can vouch for them. Mr. Brandt is also one of the first conventional farmers to help develop special seeding equipment to enable farmers to plant their cash crop directly into the residue from a cover crop. He has a lot of videos on his website, and I think they are fascinating. (I have also ordered phacelia from them, by the pound, for early spring seeding in my pollinator gardens. The bees go crazy for it.)

If you’re interested in how soil can be a huge catalyst to improving our planet (and some history on how it’s disappearance has contributed to societal failure), an excellent book is Growing a Revolution: Bringing our Soil Back to Life, by David R. Montgomery. If you’re looking for a nice film to help you understand these concepts, look for Symphony of the Soil, which came out years ago and is still one of the best films about soil I’ve ever seen. For a crash course on soil health and how cover crops can be used to improve your land, you can’t do better than Living Web Farms’ series with Roy Archuleta and Dave Brandt - these videos will blow your mind.

If I were Jill, and my garden had been decimated by heat and smoke (mine is pretty sad too, sister!), and if I wasn’t planning on winter food crops, and I wanted to improve the soil, I would plant buckwheat right now. It’ll grow and flower quickly in our late summer/early autumn heat; it’s quite a pretty plant, with lovely tiny white flowers. Around late October or early November, I would cut it down and lay it on top of the soil where it grew. This will provide cover for the soil over the winter. (Studies have shown that it’s better for the soil if you just lay the residue on the top, rather than turning it under.) Or, you can add that residue to your compost pile. I would then plant either a winter mix of grain, clover, peas, and radish (or the mix Dave sells) right into those same beds, and let it grow a bit before the real winter hits us. When it begins to warm up again in January/February, that cover will take off and grow like mad, and you can let it go until you are ready to cut it down and plant your spring crops. This will do wonders for your soil, and you will also be feeding pollinators: Both now, with the buckwheat, when it’s hot and crispy outside and there’s not a lot to eat, and early in spring, when the bugs are emerging from their winter dens and need nutrition, pronto.

Do any of you use cover crops regularly? What’s your experience with them? Do you have any tips for Jill (and the rest of us)? If so, please leave a comment down below. Good luck, Jill! Let me know if you have any more questions.

Sunburn

Over the weekend, I asked Tom to build me a sort of shade covering for the peppers. This is what he came up with and I love it. The covering is agribon, the same stuff we use to protect from frost in winter. I didn’t want the peppers to be totally enclosed, I just needed a little light protection from the intense sun in the heat of the day. This is because my peppers are suffering (and suffer every year) from sunburn.

That whitish spot at the top of the fruit is the sunburn. It’s not the worst thing in the world; the rest of the pepper ripens normally and can be used, cutting away the damaged area. But it is a real nuisance when every single one of your peppers has it. It seems to affect the bells worse than the corno di torno types, but even those get it sometimes. And here’s the thing - peppers are sun lovers! Sun worshippers! They need heat and sun to be at their beautiful best. But in our area it’s a little different, and here’s my theory about that. As you can see from the picture up top, our pepper plants never really develop that full, leafy, luscious green look that plants in other parts of the country get. It’s because of how dry it is. I have drip irrigation on these plants as I do all of my garden, and while that keeps them alive and producing, it’s not enough to produce the kind of lush vegetation that would protect the developing fruit from the direct rays of the sun. As far as I know, sunlight on the actual fruit has no affect on ripening or sweetening - it all comes from the effect of the sun on the leaves. But the plant has to protect itself from dryness somehow, and it won’t sacrifice fruit because that’s how it reproduces. So what can it sacrifice? Some of the leaves. Hence, my plants are puny but still produce a good amount of fruit.

This is just a theory. You can help me by letting me know if you live in a rainy part of the country and grow peppers. How do your plants look?

Anyway, I’m hoping the light shade cover will take care of the sunburn issue. I get it on my tomatoes, too, but it’s impossible to provide any kind of shade cover at the moment because the trellises are too big. Maybe that’s a project for next year. Shade cloth every summer over this end of the garden?

Tom has also built me a stand for my dehydrator (in full use in summertime), which keeps it out of the way but convenient. He’s become quite a dab hand at these projects, and I’m so grateful!

A nerdy side note: Do you know what your state rock is? If not, you can look here.

Our state rock is Serpentine (or Serpentinite). You can find this all across the state and is a beautiful greenish color. It is formed from igneous processes, that is, volcanic, and then is metamorphosed. I was hiking in Sunol Regional Wilderness yesterday, and once I got up into the hills, there was lots of this stuff lying around, as well as degraded sheets of it on rock faces, which is basically asbestos. Asbestos is formed as the rock weathers and erodes. The dust, of course, can be quite dangerous, but I think the rock is really lovely. There are whole plant communities that thrive on this sort of substrate, a very specific list, which is helpful to know if you live in a place with a lot of serpentine. How will you know this? You need to look at the geologic map of your property. (I wrote a post about this in the Spring of 2019.) You might enjoy finding out your own state rock and how to identify it while you’re out hiking!

Corrections on my Biochar post

I had an email from Austin at All Power Labs this evening; I had made several mistakes in my post about biochar, and of course he would like to make sure the information is correct, and so would I! I don’t ever want to mislead my readers. So, I am going to copy his email in full here. He also sent me a lot of photos of before/after biochar, which I will share with you if you like (just contact me and I’ll send them on) - they are impressive (although I haven’t seen any results in my own garden yet and will report them when I do. I have to say my artichoke plants are just as big as the ones in the pictures, so … jury is still out for me on this. The proof will be in the pudding! The important part is that Gill Tract saw a huge difference in their garden).

Here is the email, and I want to say that I really appreciate a company that is 1) local, 2) taking something out of the waste stream and making it work for good, 3) invested in solving the climate problem, and 4) totally committed to their company and feel it’s important to make sure that the info is correct and not distorted. SO thank you very much to Austin for pointing out my mistakes and setting the record straight!

“(Austin wrote:) In this paragraph, the highlighted portion ought to be corrected:

(Elizabeth wrote:) So, here’s the scoop. All Power Labs was originally created to make renewable energy using biomass. That is, make power by burning the waste products of agriculture or even our urban yards - tree trimmings, wood chips, etc. In the process of making this renewable energy, a by-product was produced - bits of what looked like charcoal, very light and made of pure carbon. Originally they just threw this product out. Then they realized it was biochar, and high quality biochar at that, and that it was a coveted resource for farmers and gardeners, as it does a lot of cool things in the soil (which I will detail in a bit). The original purpose of the company, making renewable energy for use, was having trouble finding a niche in the very large solar and wind energy economy we have in California. So, they pivoted a little into the biochar side of things.

(Austin) The biochar is not pure carbon. It is about 70% organic carbon. (Organic carbon—in a from derived from an organism— as opposed to mineral carbon, such as in chalk. Chalk is calcium carbonate. Carbonate minerals contain CO2 in their crystal structures.) The remaining 30% is a mixture of ash, and residual oxygen and hydrogen. Our walnut shell biochar is about 15-16% ash.

Charcoal is the “fixed carbon” fraction of woody biomass. About 80% of the mass of a chunk of wood consists of volatiles, which come off as wood smoke. The volatiles contain about half of the carbon of the wood, along with most of the hydrogen and oxygen in wood. (Remember, wood is largely cellulose, which is a carbohydrate. That’s where the hydrogen and oxygen come from.) The remaining 20% of the mass is fixed carbon—the carbon that is left once all of the volatiles come off of the material. That’s where the other half of the carbon content resides. The fixed carbon remains, and if it goes through high temperatures, resists decomposition because the enzymes used by bacteria and fungi to break down most organic carbon compounds can’t decompose most of the structures that are produced by fire. The higher the temperature, the more resistant to decomposition pyrogenic carbon tends to be. This quality of resisting decomposition is called “recalcitrance”. It is not an absolute quality; lower temperature processed biochars have a larger fraction that eventually decomposes; the high temp processed stuff (like ours) has a very small fraction that eventually decomposes.

(Elizabeth) Now more about the process. Above is a photo of the “Powermass Gasifier” which is the machine that turns biomass into both energy and biochar.

(Austin) The name of the machine is the “Power Pallet.” It is a Biomass Gasifier genset.

I attached a process explanation for you to get a sense of how it works. (If anyone is interested in this - let me know and I’ll send it on to you - E)

(Elizabeth) Biochar doesn’t decompose. It’s already been processed into its permanent form - pure carbon. This happens in the process of Pyrolysis. The volatile carbon in the biomass is burned off (and used for energy), and what is left is like the embers of a campfire. Totally indestructible, permanent bits of carbon.

(Austin) This description, of being “indestructible, permanent bits of carbon” is more apt for diamonds or pure graphite. Biochar is not totally indestructible. Depending on how it is made, a certain fraction can very slowly decompose, but the bulk of it does not participate in the carbon cycle. The proportions depend on the temperature of processing. The proper way to state this is that the carbon content of charcoal does not revert to carbon dioxide without combustion. When charcoal is interred in the ground as biochar, it is essentially “reverse coal mining”—the production of concentrated black carbon and putting it in the ground.

Also, for pyrolysis, we have an explanatory page on our website that would explain it in the context of how we make biochar. If you would link this page, we would appreciate it:

http://www.allpowerlabs.com/gasification-explained

(Elizabeth) They have a very high CEC (cation-exchange capacity) which means that they add nutrient density to the soil.

(Austin) CEC doesn’t add nutrient density, but it does add the ability to store nutrients. It is more like nutrient storage capacity. The key thing is that water soluble cation nutrients don’t just dissolve into water and leach out; the CEC sites act like velcro and cling on to water soluble cation nutrients, but hold them loosely enough that plants can get them off as they need them. High CEC soils can store a massive amount of nutrients without burning plant roots because the nutrients are not all dissolved in the water at once.

(Elizabeth) I also really appreciate that the biomass used to make this biochar is nut hulls from California orchards. This is taking something out of the waste stream, something that takes hundreds of years to decompose, and putting it to good use.

(Austin) The nut shells don’t take hundreds of years to decompose. Depending on how they’re disposed of, within a few years, all the carbon content in them is back in the atmosphere. This is sort of like how wood chips and nut shell mulch disappears like compost. ”

— Austin Liu, sales engineer, All Power Labs

Let me just say again: I totally appreciate these corrections. I want to learn, too!

Learning about Biochar

A couple of Tuesdays ago, I gave a talk at the Merritt College Horticulture Department, in their Design Forum. The talk was centered around how to create an urban farm in a typical residential yard, as we have done here. It was a great night, filled with interesting questions from the audience, and as usual, I not only doled out some learnin’, I also received some learnin’. Every conversation I have with gardeners or farmers leaves me with new impressions and new knowledge, and then, of course, new questions.

One audience member asked me if I had any experience with biochar. The short answer was no. The slightly more detailed answer is that I’ve done some reading about it, and watched some educational videos from Living Web Farms about how to make it and apply it to your garden. I’ve also heard some negative things about it - that it’s a hoax - and I also have had some reservations about the way it is made; I have worried that the process of creating the biochar is actually releasing a lot of carbon into the atmosphere. The student who asked the question showed me some pictures from her own garden, of plants grown side by side, with and without biochar. Looking at those pictures, it was clear that there was a difference in the size, health, and production of the plants that grew WITH biochar. This intrigued me and I wanted to source some biochar of my own to try.

As my friend Lawrence likes to say, serendipity is everywhere, and that same night I happened to pick up a free copy of the fall edition of Edible East Bay magazine (which they make available in the Hort Dept), which I always enjoy and learn a lot from. And wouldn’t you know it, there inside was a huge article about biochar, and a story about a company that makes it in Berkeley (All Power Labs, more on them in a minute) and a community farm, Gill Tract, that has been trialing the biochar in their compost and raised beds systems. Well. I immediately contacted the lab and signed up for a year’s subscription of biochar. Today I went to pick up the first batch, and was absolutely blown away by the welcome I received from Aidin at All Power Labs, who then spent a good deal of time showing me around the joint and explaining the process of how biochar is made. He also welcomed me to the Local Carbon Network, which is a “community-powered local drawdown network.” I love this and I love that I’m a part of it, officially, though honestly I’ve been a part of it for years. :)

At the end of my visit, I mentioned Merritt and said that the Hort Dept should do some trials of their own with this product, and Aidin said, “What a coincidence, my coworker Austin is giving a presentation at noon at Merritt,” which turned out to be in my friend Lawrence’s permaculture class! I texted Lawrence and asked if I could drop in and hear the lecture and he kindly allowed me to do that, and I got to hear the details all over again (and take notes this time) which really helped cement the ideas in my brain. More serendipity!

So, here’s the scoop. All Power Labs was originally created to make renewable energy using biomass. That is, make power by burning the waste products of agriculture or even our urban yards - tree trimmings, wood chips, etc. In the process of making this renewable energy, a by-product was produced - bits of what looked like charcoal, very light and made of pure carbon. Originally they just threw this product out. Then they realized it was biochar, and high quality biochar at that, and that it was a coveted resource for farmers and gardeners, as it does a lot of cool things in the soil (which I will detail in a bit). The original purpose of the company, making renewable energy for use, was having trouble finding a niche in the very large solar and wind energy economy we have in California. So, they pivoted a little into the biochar side of things.

Shortly after that, they partnered with Gill Tract farms to do some trials and figure out how this stuff really works. Bob Flasher at the farm has been working closely with APL and seems to be quite sold on how the char performs in his garden and has documented how the plants perform. Knowing that he has been an early adopter of the char helps me to feel good about moving forward, trying it in my own yard.

Now more about the process. Above is a photo of the “Powermass Gasifier” which is the machine that turns biomass into both energy and biochar. The energy now is used to run the machine, so it’s a closed loop - no emissions or volatiles are escaping into the atmosphere. In fact, the carbon that is trapped in the biomass is turned into a product which can help sequester carbon into the soil. At this point, you might be saying, “Well, doesn’t compost do that too?” and the answer is yes, it does. It helps feed the microbiology which are turning the compost into humic acids in the soil, which do sequester carbon. There are some problems with compost, though, which you might have experienced (I know I have). One, it doesn’t last more than a season. I put a couple inches on my beds each fall, and by early summer, the beds look like they never had it. The soil surface is quite low, several inches below the top of the wooden beds. What happened to the compost? Well, some was turned into nutrients for the plants by the microbiology in the soil. Some, however, was off-gassed, releasing carbon into the air again as it decomposes further. Compost does continue to decompose, it doesn’t stop just because you’ve moved it to your veg beds.

walnut hulls, an abundant waste product from California orchards, which will be turned into biochar

Biochar doesn’t decompose. It’s already been processed into its permanent form - pure carbon. This happens in the process of Pyrolysis. The volatile carbon in the biomass is burned off (and used for energy), and what is left is like the embers of a campfire. Totally indestructible, permanent bits of carbon.

These bits of carbon, if applied to a garden/farming system, become hosts for a ton of microbial life. They absorb humic material. They have a very high CEC (cation-exchange capacity) which means that they add nutrient density to the soil. It improves drainage (tilth) while helping with water retention, as they can absorb many times their size in water. They improve friability of soil. They store the mineral nutrients from biological processes. They even, apparently, bind heavy metals and immobilize pollutants.

These are the composter tumblers that they are using at All Power Labs to do their own trials with biochar. And Aidin was clear that they recommend that we compost biochar first, not just add it directly to planting beds. There the biochar will be inoculated with the microbia of the compost pile and start to do work. There is a lot of evidence from Gill Tract Farm that adding biochar also increases the temperature of compost piles by quite a lot (this is something I desperately need). Not only that, Gill Tract has seen the temperature spike and then remain at high temperatures for six weeks after an application of biochar! I’m hoping to see this in my own compost piles. I came home with a large bucket of char, and added only a cup to the worm bin and about 10 cups to the large compost pile in the chicken run (they recommend adding 10% biochar by volume, an estimate is ok. My bucket should last three months). We’ll see how that works to activate heat and decomposition.

I also really appreciate that the biomass used to make this biochar is nut hulls from California orchards. This is taking something out of the waste stream, something that takes hundreds of years to decompose, and putting it to good use.

If you’re interested in your own subscription of biochar and live in the area, you can contact Aidin at The Local Carbon Network. It’s not cheap, I’ll warn you now, but I imagine that in time, when the benefits of biochar are documented and realized, the price will level out. I also believe it is worth it, if it will help me process enough compost to add two inches to all of my planting beds once a year. This would be terrific because I’m tired of buying compost, for many reasons: price (a lot more than this biochar), the unknown ingredients and their provenance, and the work/energy to get it here. So I’m invested in trying it to see if I can start to produce more compost here, in my yard.

To learn more about biochar, another good resource is the book Kiss the Ground , which is also, I believe, a movement that is part of the Marin Carbon Project.

The back of All Power Labs, which I just love. So Berkeley!

Have you tried making or using biochar? If so, I’d like to hear about it!