Sprouting Broccoli on left was planted in soil enriched with biochar

Turn brush and scraps into a useful soil amendment with Biochar.

Biochar is a charcoal fired in a low-oxygen stove at temperatures twice as hot as fuel charcoal, which makes a cleaner product (I rubbed it in my fingers, see photos below). The burn method sequesters carbon instead of releasing it into the atmosphere as does brush-fires, burning the Amazon, or letting brush decay over time.

Creating biochar can make use of scrap wood, bones, woody brush such as blackberry vines and scotch broom. Making bio-char could solve a common disposal problem for Islanders and create a useful amendment for acid soils in the garden.

Biochar makes a long-lasting soil amendment that can raise pH in soils, store water, and create in-soil habitat for soil microbes. It can substitute for liming in acidic soils and has an immediate and long-lasting effect.

At the Sustainable Practices meeting, Art Donnelly of SeaChar.org will talk about bio-char: what it is, what it’s good for, how to use it in the garden and for carbon sequestration. He’ll bring examples plus a couple models of biochar stoves. 

In the “with/without” photo above, Islander Ken Miller shows the difference between sprouting broccoli planted in a bed that contains biochar, and a bed without. He told me the major difference between these beds is the biochar in the bed with the bigger broccoli—even though the other broccoli was planted earlier and in more sunlight. 

I saw Ken demonstrate his biochar stove at the Compost Fest (photos below). His five-gallon metal bucket can, within approx. an hour, render scrap wood like alder or blackberry vines into biochar at temperatures reaching 800°. Similar stoves will be at the Thursday demonstration.

Ken plans on holding a stove-making workshop in January: for a nominal fee of $35-40 (estimated at this time), you will walk away with a biochar stove (see photos of the demonstration below). He says “People should see a demonstration before doing biochar production at home; I’d hate to see somebody go home and light up their garbage can with a bunch of wood in it.”

Here’s a link to a 10-minute video on biochar, showing the burning process and results: www.youtube.com/watch?v=RXMUmby8PpU

For more information, contact Sustainable Practices chair Kyle Cruver at kyle@cruverdesign.com or phone him at 567-4068. Or contact Ken Miller (my source), who demonstrated his biochar stove at the Compost Fest:  islandcanyons@yahoo.com.

Ken Miller shows off his biochar stove at Compost Fest. From upper left: loaded stove with oxygen exposure; the burn begins; stack in position (no burning happening); a clean piece of biochar AFTER I've rubbed it around in my hand.

First off, my compliments to Cathy Fulton of Mariposa Gardens for the Compost Fest last Sunday, October 19th. The event was well staffed with knowledgeable folk, good signs, and a funky richness of garden techniques to try out (see photos of the broadfork demo, below.)

(Update 10/24: I just got the link to all the signage from the Compost Fest. These quick-info pages describe a process in words and photos, then list pros and cons, perhaps other resources. Included: hot composting, slow/cool composting, animal bedding/offal composting, chicken cultivators, bio char in trenches, hugelkulture heaps, sheet mulching (aka lasagna beds), and stinging nettle tea.

mariposagardens.org/Handouts/Composting/Compost_Festival_Displays.pdf

Bio-char

I got there just before the opening at 11am, but things were already well under way. Ken Miller, already surrounded, was busy explaining his 5-gallon bucket stoves for making bio-char. This ancient process takes bio-mass (chunks of wood, bones, or brush) and reduces them to charcoal chunks you can fold into your soil to hold water, add minerals, provide soil habitat, and sequester carbon.

I’ve invited Ken to either write or be interviewed about bio-char for this blog, so more later on that topic. My biggest hope for bio-char: it provides a garden way to dispose of chicken bones.

(note on 10/20: Ken provided a mini-stove—two 16oz fruit cans that slip together to make one combustion chamber—that you can fill with sticks and throw into your woodstove. I did that, and after one firing in my Russian Stove, I had a little pile of, basically, artist sticks of charcoal. COOL!

Why is Her Compost Hot and Mine Not?

Per the name of the event, Cathy had several types of compost piles going: hot piles, cold/passive piles, a pile to handle animal wastes, compost cones, and sheet composting (also known as lasagna beds or composting in place). I talked to her most about the hot method, which can, with a bit of work, give you compost in a month.

Her hot pile was four feet high, contained by pallets on edge, and layered with once-fresh grass clippings, horse manure, apple pomace left over from cider-pressing, and spent hay. And it was steaming warm, the thermometer showing a weed- and pathogen-killing 110°. 

Now my pile, made September 21 and turned on October 7, has almost the same ingredients, yet barely reached 90°. So we talked: Cathy thought my pile needed the firing power of fresh grass, plus another turning, to fire my compost to the desired temperature. (Later I realized she also shreds her ingredients to make them easier for the compost-critters to digest).

When I got home, of COURSE I went in search of fresh grass, and I found it on my downward slope. It was long, true, but the recent rains had fed lush new growth, so I hand-scythed the new greenery and hauled half a barrel’s worth to the compost. Turning that compost once again, periodically I grabbed a handful of that long grass, snipped it into strands and let it fall in a shallow layer on the rising pile. Hopefully this green food will fire up the compost, instead of matting within it. I’ll track temps through the week: if this works, it should climb 50° by week’s end.

(Update 10/24:  by week’s end, the heat had topped out at 80°. Rereading her pdf hand-out (see link above to “hot composting”), I see that A) she shredded her compost, and B) she used more grass clippings than manure. Since the mowing season is over, I think I’ll have to wait until spring to try this again).

The Broadfork: A Big Bite into Your Earth

This broadfork for double-digging has been teasing the edges of my gardening radar for some time, so I was happy to get a chance to try one out. Meadow Creature, which is Bob Powell and his partner Margot Boyer, have made “several dozen this year and sold half to Islanders, half in web sales to gardeners around the USA.” The steel is cut at Vashon College, using its OMAX water jet cutting machine, and painted in gaily neon colors by Bob. They go for $200 plus tax.

That’s quite a bit of dough for my small garden, so I was glad to try one out. In the photos below, you can see the basic motion: you lift this 25-lb fork and let the tines fall into your soil. Stand up on the cross-bar and wiggle the fork around to sink the tines deeper. Then, as you lean back, the leverage you’re applying on the handles make the tines in the ground pry soil upward, loosen it as deep as 16″ underground.

The idea, I think, is the tool uses the power of leverage to do the “heavy lifting” work of double-digging, which is usually done with a garden fork or shovel. Anyone who’s read “Bio-Intensive Gardening” will recognize this tool.

For my small garden, this tool is more than I need. For a large garden planted in rows or wide beds, that isn’t tilled mechanically, and HAS a person with some heft to persuade those tines down into the earth, this might be a useful, if occasional, tool.

For more: info, email Margot or Bob at sales@meadowcreature.com or visit www.meadowcreature.com.

I know I’ve obsessed about compost. We’re coming on the perfect time of year to turn piles, empty those piles as mulch, and start a new pile. 

If however, like me, you’ve stared at your carefully-layered and wetted heap, wondering why it doesn’t heat up to weed-killing temps like the books say, this Sunday’s event might be for you. Mariposa Gardens (www.mariposagardens.org) is holding a—

Compost Fest “Let It Rot” from 11am–3pm, Sunday, October 18.

Here’s the outline of the program:

• Quick/hot composting
• Sheet composting
• Slow/Cool composting
• Animal bedding/Offal composting
• Worm bins
• Hugelkultur experiments
• Two ways to make bio char  (that starts at 11:30)
• Fall garden prep demo
• Breaking new beds demo
• Vashon Broadfork demonstrations
• Chicken-Garden partnership
• Carbon sequestration

        …and more!

I don’t see that there’s a cost, but you can feed the donation jar if you like. The event is considered a “come and go” event: you don’t have to stay the whole four hours, but instead wander around, take in whatever you want and ask questions of the demonstrators who will be doing their “thing” throughout the day.

Cathy Fulton says “it’s great to get a chance to try the broadfork. It’s an expensive tool and pretty heavy, but it’s great to open up soil for the first time. So I appreciate the chance to try it out first.”

Mariposa Gardens is off Monument road. Here’s directions: note she wants folks to park on Monument and walk in. 

Address: 9228 SW 209th Street

From the intersection of Vashon Highway and

204th Street (the Sound Food intersection), go east

(toward the high school and pool) about 1/3 mile.

Turn right (south) on Monument Road. Go about

1/3 mile to 209th Street, which is a gravel road to

your right.

209th Street is a one lane road. To avoid a traffic

jam, please park on Monument Road and walk

about 500 feet to the site. There is accessible

parking at the site for those who need it.