CooKit Solar Panel Cooker


I’ve been experimenting with a nice panel solar cooker for the past week and, so far, the results are impressive. Called the CooKit, it was developed in 1994 by a group of engineers and solar cooking enthusiasts associated with Solar Cookers International and based on a design by Roger Bernard.

It has a couple of nice features:

  • It produces ample heat to cook rice and simple casseroles.
  • When you fold it up it takes up no more space than an album (do I have to explain what an album is for the youngsters out there?).
  • A flat area on the base of the CooKit makes weighting it down with rocks easy. This is really important in windy places.
  • All you need to build it is a knife, cardboard, aluminum foil and glue.

As with all panel solar cookers you need an black enamelware pot wrapped in a turkey roasting bag to hold in the heat. You ain’t gonna deep fry things with a panel cooker, but they are great for slow-cooked crock pot type dishes. The only disadvantage to this design is having to cut curves, but with a sharp knife it wasn’t difficult. The other improvement would be a stand to lift the pot off the aluminum foil for more efficiency and to keep the cooker un-scuffed. When panel cooker season returns to LA in the springtime, you can bet I’ll be making a lot of rice with this thing.

Detailed instructions for how to build a CooKit can be found here.

Also, Mrs. Homegrown and I are writing a new book and we’d like to include some plans for solar cookers (any kind). If you’ve got a favorite DIY model, leave a comment with a link.

Another view with curious Doberman in the foreground:

Quince: the “Poster Child of Slowness”

Oops–I think they mean “quince

A year ago I planted a “Karp’s Sweet Quince” tree from Raintree Nursery and blogged about it, saying that I’d like to hear from fruit expert David Karp for whom the tree is named. Karp called me a few weeks ago to say that he was working on a quince article for the LA Times, “There’s a new taste for quince“. In the article Karp discusses varieties that can be eaten raw as well as how our Southern California climate is an ideal place to grow quince. Karp asked how my tree is doing and I had to say that it’s not doing all that well. In a fit of mad, rare fruit tree planting fever, I put it in a crappy location, in bad soil too close to a large prickly pear cactus that is probably competing with it. We’ll hope it does better in the next season.

Filling in for my lack of backyard quince, Homegrown Neighbor was nice enough to pop by with some she bought local Asian market. The label must have lost something in translation, but refers to a variety called “Pineapple quince”. Karp points out in his article that this is the most prevalent commercial variety. When picked fresh it could conceivably be eaten raw, though the commercial stuff ain’t fresh.

Quince is indeed, as one of Karp’s sources notes, “the poster child of slowness.” I tried to make some jelly with it and greatly underestimated how long it takes to cook. The jelly did not set, so I’ll have to try again. But the fruit did fill the entire house with a heavenly scent. Definitely a fruit worth slowing down for.

A Warning About Straw

Claude Monet used straw (or is that hay?) for art. We use straw to catch chicken droppings!

Straw is a very inexpensive and useful material for composting, mulching and animal bedding (we use it for all of these purposes). If you use it for mulch you’ll probably get some seeds that will germinate, but I’ve never found it to be a big problem in a small vegetable garden. I get my straw from the feed store, but you can often get it for free from yuppies on Craigslist who have bought it to give their parties the Hee Haw ambiance we enjoy 24/7 at the Homgrown Evolution compound. If you buy it from the feed store remember to ask for straw, not hay. Hay is green and a lot more expensive. You feed hay to your horses.

But one warning from my friend, permaculturalist David Kahn. It’s tempting to pick up bales that stores have used after Halloween, but make sure they weren’t treated with fire retardant. Fire retardant has some nasty chemicals in it you don’t want in your garden. When in doubt, just go to the feed store–straw it ain’t expensive!

Addendum 10/27/09: Reader Polyparadigm raised another potential issue with using straw in your garden or compost pile: halogenated pesticide/herbacide residues. Clopyralid is an example–while banned for use in lawns in many places it’s still allowed on hay and grain crops . All the more reason to grow your own mulch and carbon materials if you can–don’t throw out those fall leaves! Here’s what Polyparadigm says:

“I’m glad I read through to the end! I was thinking this would be a warning about clopyralid and its close cousins. Which bears some mention: Halogenated pesticides aren’t broken down by any but a few soil organisms.

Clopyralid and aminopyralid mimic the hormones in broad-leaf plants, causing them to grow un-evenly and die from wrong-facing, crinkled leaves and other symptoms. Grasses are un-affected, so fields of grain and lawns have been sprayed with this sort of chemical, as a cheap way of keeping broad-leaf competitors at bay for a few years.

These chemicals have a half-life of 11 months in hot compost, and are often applied at such high rates that certain plants won’t grow in garden soil dressed with finished compost from a mix of sources, if one of those sources is a treated lawn or field.

A quick bioassay will test for this in straw: peas sprouting from soil mixed with that straw will look deformed if the field that grew the straw was treated. Browns of a similar texture from a source you know to be clean should probably be used for a control group.”

Stirred, Not Shaken


“Matter is never without spirit and spirit is never without matter.” – Rudolf Steiner

This past weekend I had the good fortune of attending an amazing workshop in biodynamic gardening taught by master gardener Dory Rindge. For those of you unfamiliar with biodynamics, it’s a system of agriculture based on the work of early 20th century philosopher and mystic Rudolf Steiner.

In the 1920s, at just the point when chemical fertilizers where catching on, Steiner proposed a radical return to organic farming. Biodynamic agriculture combines common sense practices such as composting with strange esoteric rituals. The oddest aspect of biodynamics involves the “preparations”, a specific set of substances made of manure, silica and herbs that are buried in cow horns, bladders and skulls. After a few months they are unearthed, ritually stirred and applied to soil and compost piles. Steiner has the biodynamic farmer spray these preparations on soil, plants and compost piles to act as a kind of homeopathy for the land.

While we did not make our own preparations in class (it’s complicated!) we did a ritual stirring with pre-made preparations in buckets of water. Using sticks we created vortexes in the buckets, alternating in clockwise and counterclockwise motions. We then divided the mixture and rushed home to spread it on our gardens.


I was excited and inspired by the class, a feeling which deepened when manure filed horns appeared to me in a dream. In my dream I interpreted the symbolism of the horns–that they represented a higher world unified with the earth by being buried and containing manure. It’s a symbol that recalls the ouroboros, the snake chasing it’s own tail, representing the cycles of nature, combined with the “as above, so below” gesture the magician in the tarot deck is making below. All this makes more sense if you compost!

Now I’m a big fan of the scientific method (yea soil tests!) but I’m increasingly dissatisfied with our modern culture’s overly materialistic world view. As the subtitle of this blog hints at, “cultural alchemy”, I’m interested in symbolism. But I agree with our our instrutor Rindge that it’s important not to get dogmatic about this stuff.

And I could care less about the science of the preparations. If you are, here’s a study that says its hokum and here’s another one that says they work (pdf). To focus on the biochemistry of the preparations seems to me to be asking the wrong questions. What I like most about biodynamics is its sense of intention. It’s an intention that ties us to the land, to the elemental spirits of plants and animals that were tangible to our ancestors. We could all use ritual that ties us to nature and I look forward to stirring preparations and perhaps making them with a few close friends. In fact, I’m much more excited about making preparations than it buying a package through the mail. Steiner’s set of herbs all grow well here and many of them I have already. But a cow is kinda hard to come by in Los Angeles. While it may be heresy to some, perhaps we’ll have to come up with some modifications to the rituals that make sense in this particular place and time.

More on biodynamics, specifically planting by the cycles of the moon and planets, when Mr. Homegrown gets back from San Antonio next week.

Let’s Get Biointensive

I picked up a handy tip on plant spacing from John Jeavons’ book How to Grow More Vegetables. Jeavons dislikes rows and instead uses the triangular spacing of the French biointensive method. You can view a nice diagram of biointensive spacing on the LandShare Colorado website. And see some images of the way Jeavons’ spaces his garden on This Girl’s Gone Green. Triangular plantings squeeze more veggies into small spaces. The tight spacing, with leaves allowed to just touch each other when the plant is mature, also creates a living mulch which shades the soil and saves water.

Jeavons suggests cutting out some triangles in different sizes to assist in planting. Using scrap wood, I made triangles in 3, 4, 6, 8, 12, and 15-inch sizes, taking the spacing suggestions in Jeavons’ charts for the seeds I had planted in flats. When it came time to transplant the seedlings I used the triangles to create hexagonal blocks of tightly spaced veggies. Cutting a notch in the corners of the triangles would be a slight improvement and allow for easier planting.


I could end this post leaving you all to admire my pretty little seedlings planted in neat biointensive rows. But here at Homegrown Evolution we believe in telling the truth. Growing vegetables has its frustrations. The day after I planted our winter vegetable garden (we have two growing seasons here in Southern California), we had a freak October heatwave, causing a panicked run to the nursery to buy some shade cloth. This was followed by one of Mr. Homegrown’s notorious gardening meltdowns, dreaded by the very patient Mrs. Homegrown. We’ll keep our fingers crossed that I got that shade cloth up in time.

Least Favorite Plant: Tree of Heaven

Detroit Tree of Heaven Woodshop’s new ghetto palm farm. Photos from the Detroit Tree of Heaven Woodshop.

Riding on the Amtrak San Joaquin train two weeks ago I discovered a new metric: the economic health of a city can be judged by the size of its trees of heaven (aka Ailanthus altissima, aka “ghetto palm”). The higher the ghetto palms, the more likely a city is to be in the crapper.

Tree of heaven is a super weed much reviled by gardeners and landscapers for its unstoppable ability to grow in nearly every climate in the most inhospitable conditions. In a move that will raise a lot of horticultural hackles, the Detroit Tree of Heaven Woodshop has gone beyond the “if you’ve got lemons make lemonade” phase of their project and has deliberately planted a ghetto palm farm. From their press release:

“Detroit Tree of Heaven Woodshop has established its first Tree of Heaven Farm on a vacant Detroit city lot for future harvest. We planted seedlings in beds of car tires. The tires protect the young trees while they are growing but also determine their lifetime to a size when the trunks are suitable for processing. We assume this period of growth to be approx. 40 years. Within this timespan we will maintain the plantation and keep the lot free of any kind of real estate speculation or building activity. The plantation has been realized with the support of the SMART Museum of Art, University of Chicago and a documentation is on display in the current Heartland exhibition.”

The Detroit Tree of Heaven Woodshop has turned sculptures and made furniture out of tree of heaven for a few years now. They’ve also come up with a stinky tree of heaven sauna:

“We have another small installation in the SMART Museums Heartland exhibition: A humidifier is installed in the museum lobby. The water tank of the device contains some pieces of Tree of Heaven wood (coll. Ghetto Palm). This is how the active substances get extracted in traditional Chinese medicine to cure a wide range of ailments from digestion problems, mental conditions, balding, to asthma and even cancer. In these tough economical times, a constant flow of steam will benefit all visitors with the spirit of this true Detroit resource.”

Invasion biology becomes art. If you can’t beat em’ you might as well find a use for em’.

Kimchi Secrets Revealed

Kimchi champion Granny Choe at Krautfest 2009 – photo from Eating L.A.

The last time I tried to make the spicy Korean fermented cabbage dish known as kimchi it was such a disaster that Mrs. Homegrown exiled the batch to the back porch where it rotted for a good two months before we got around to sending it to the landfill. At Krautfest 2009, which we helped organize back in September, we had the great privilege of learning to make kimchi from kimchi entrepreneur Oghee “Granny” Choe. And thankfully, Pat over at Eating L.A. has put Granny Choe’s recipe online for all to enjoy here. Having tasted Granny Choe’s kimchi, I can tell you that it’s not to be missed even for the kimchi-phobic.

You can order Granny Choe’s kimchi online at grannychoe.com.

Granny Choe also has a nice recipe for a savory kimchi pancake here.

Here’s some photos of Krautfest 2009 via Mark Frauenfelder.

How I Learned to Stop Worrying and Love the Grub


Why start the day with the Wall Street Journal when the real excitement is to be found in periodicals such as Backyard Poultry Magazine? While our broke nation can’t afford missile shields or moon trips anymore, at least it’s comforting to read in the pages of BPM that the citizens of Bonner Springs, Kansas can visit the brand new National Poultry Museum. This month’s issue of BPM also has a fascinating article by Harvey Ussery, “Black Soldier Fly, White Magic” on raising black soldier fly (Hermetia illucens) grubs as poultry and fish feed.

“If we offer the grubs 100 pounds of food wastes, for example, they will reduce it to 5 pounds of residue usable as a superior soil amendment, in the process generating 10 and possibly up to 20 pounds of live grubs that can be fed to livestock; in addition to liquid effluent (how much depends on the moisture content of the feeding materials) which can be used to feed crops. Hey, wait a minute–what happened to the “wastes”? There is absolutely no waste remaining after this conversion–it has all been transformed into valuable resource.”

To raise Hermetia illucens you put vegetable and fruit trimmings in a container with a small opening for the black soldier fly females to fly in and lay their eggs and a method for the grubs to climb out of the compost. You can also feed them small amounts of fish and meat but they can’t digest cellulesic materials. A company called ESR International markets a black soldier fly growing system called the BioPod™ at www.thebiopod.com. A spiral ramp in the BioPod™ allows the grubs to scamper out of the feeding materials and launch themselves into a bucket. Each morning you empty a bucket full of grubs for your grateful chickens or fish, making sure to reserve a few to ensure future black soldier fly generations. Adult black soldier flies don’t bite and are only interested in flying around looking for sex and, in the case of the females, to find a good place to lay eggs.

At $179, the BioPod™ is above our humble slacker budget level, but you can make your own out of the ubiquitous five gallon bucket. While I haven’t tested this design, there’s some simple plans on this informative blog devoted to the black soldier fly. The author of this blog, “Jerry aka GW,” cautions that growing grubs requires attention to detail and will be easier in warmer climates such as the southeast and west coasts of the US where soldier flies can be found in the wild. While you can buy black soldier flies to populate your composter, it will be easier to grow them where they already live. Here’s another DIY grub composter. If any of you have experience with building one of these please leave a comment.

And while you’re ditching the Wall Street Journal, why not skip the Netflix this evening! Here’s a video on grub growin’ complete with a dramatic musical conclusion:

The crank in me has to add that simple ideas like becoming a grub cowboy are more exciting, and have greater potential than all the Priuses and algae fuel schemes combined. Growing grubs is an activity many of us have done accidentally. Making use of those grubs is just a matter of inserting ourselves into one of nature’s clever recycling schemes.

A Cheap Soil Testing Service

I’ve started a new method in the garden: test the soil, amend according to the recommendations and grow. Lather, rinse, repeat. In many parts of the U.S., you can get free or low cost soil tests from your county extension service, but not here in Los Angeles. Some time ago I answered a reader’s question about where to get soil testing done, only to have to correct my response several times. Last week, Homegrown Evolution pal and the editor of Cool Tools, Elon Schoenholz, gave me a definitive answer on where to send soil for testing: the University of Massachusetts Amherst, Department of Plant and Soil Sciences Soil and Plant Tissue Testing Laboratory. A standard soil test is $9, $4 more for the standard test plus organic matter. The standard tests includes heavy metals. That’s a bargain, and you don’t have to be a resident of Massachusetts. They also offer compost, fertilizer and plant tissue tests at reasonable prices.

Read a review of UMASS soil testing by master gardener Amy Thompson at Cool Tools.

My Big Fat Greek Squash


Every time I visit my mom, her Greek neighbor pops over the fence to offer me seeds and plants. He visits Greece each summer and comes back with seeds for plants whose names he can’t translate into English. As a result I always have a few mystery Greek vegetables growing in the garden. This spring he gave me a squash seedling he had propagated. It grew into a massive vine and produced two winter squashes whose weight exceeded the capacity of my kitchen scale. I harvested them last month and we’ve been eating a lot of squash!

The skin turned a kind of manila envelope color and the flesh was a deep orange. It kind of looks like a butternut squash on steroids. The flavor resembled pumpkin, but tasted a lot better than most pumpkin I’ve had. We roasted one squash to make squash tortellini among other dishes. The best recipe, however, was for a savory winter squash pie (galette) out of Mark Bittman’s book How to Cook Everything Vegetarian (thanks to Bruce of the Green Roof Growers for suggesting this book). Bittman’s spicy winter squash galette recipe is here on MSNBC along with a video of him making it. I’ll note that the online recipe is different from the one in the book which calls for a longer baking time. My galette was in the oven for over an hour, but I did not cook the squash as long in the frying pan as Bittman does in the video. I’m sure either way will work, and this has to be, seriously, one of the best things I’ve ever cooked. It would make a great substitute for the always dry Thanksgiving turkey.

And I’ve made a mental note to myself to grow more winter squash next year. I like the taste better than summer squash and you can store it in the pantry for later use (hence the “winter” in the winter squash).

If you’d like to hazard a guess as to what this squash is called (especially if you’re Greek), please leave a comment.