I may get a chance to help design a garden for a charter school.

They're using a lot of methods from Waldorf education, and while Waldorf is an intellectual cousin of biodynamic farming, I really don't comprehend alchemical/homeopathic/astrological methods and don't expect them to work for me.  The garden is going to have to fit into a small-to-medium plot and into a working-class neighborhood of a large city, which I have heard permaculture can do. 

My rough understanding is that biodynamics is to permaculture as Elvish is to Esperanto, so it might be a better fit culturally, too. 

I'm wondering what advice you might have.

A little information:

The plot will be in Oakland, CA, where it never snows and doesn't quite rain enough

I have more time to contribute, than money

I can run a compost pile, am good at building/tinkering, and tend to analyze better than I synthesize

I'll likely get access to the property in November, and it might be a community garden until the school opens the following September

The existing soil might be contaminated

Most of the sites being considered are less than a half acre, most have flat terrain, a significant paved area, and existing fences and other structures; I won't know more for months

Craigslist and Freecycle, among other resources, can provide copious local paper, wood chips, fill soil, cordwood, building supplies, furniture, etc. for free pick up, or even with free delivery.  Cafes that give spent grounds to a good home and a community seed exchange are among the other prominent resources.

The school will serve families from many different cultures, so parents may offer traditional expertise, and the school will probably appreciate very diverse garden products

My ideas so far:

If the soil is contaminated with heavy metals, lay down broken drywall from demolition sites and/or some other source of lime, and only use the soil above that new, white layer.

Compost any soil where the only contaminant is non-halogenated organic chemicals.  I've heard human hair helps balance petroleum in compost, so I might ask some of the local barber shops.

Take delivery of some free wood chips...the company I plan to ask only delivers in 14 yard batches.

If one of the parents knows how to pyrolyze wood safely and in quantity, work with them to make several bushels of charcoal from wood chips and/or cordwood.

Build up raised beds about 3 ft. high to minimize bending over, with cordwood, wood chips, weeds , coffee grounds, charcoal dust, possibly rock flour, outside soil if necessary, finished compost if any is available, and more wood chips.

Plant some winter cover crops, or whatever might be most useful in marginal soil over a northern California winter.

As an engineer, I imagine the kids would enjoy a hand-cranked gravity-fed rolling mill to crush  compostables with.  I could probably build one from scratch, or adapt it from salvaged equipment, and it shouldn't be too hard to rig it so the crank doesn't turn if the hopper is open.

I'd welcome any advice.  The article on hugelkultur was most helpful, as was the forum thread about what to do first on new property.

Joel

sounds wonderful and well thought out..the raised beds should really help to avoid the contaminated soil. Will this be a permanent situation or only temporary..if it is large enough I would suggest at least one shade tree..if not able..maybe some dwarf fruit trees up in those raised beds to bring in some shade..i'm sure in Calif some shade would be welcome.

It sounds like you have a pretty good handle on things to me.  On pavement, there's only a few options: raised beds like you said, break the pavement, aquaponics (personal favorite), vine crops from buckets with trellis, and probably a some others.

One thing that occurs to me about the possibly contaminated soil is that you may want to contact paul stamets at www.fungi.com.  I've read some of his material about using fungi to clean up various contaminations.

I need to read up on aquaponics.  Thankfully, I got a copy of the design manual yesterday.  I wonder how evaporation might be kept lower than precipitation, and I imagine the pavement would need some work in order to be water-tight.

Vine crops are almost a foregone conclusion since a fenced yard is mandatory, though I hear growing grapes in this climate isn't trivial.  I will definitely look into that.

I'll also look into fungi.com.  I imagine any contamination would be old enough that appropriate spores have found their way there already, but I love information.

I think there are plans to break up pavement as well.

Rather than try to clean stuff, I would avoid it.  Toxins and the like just give me the willies.  It's one thing to try to heal some poisoned land - it's another to eat from poisoned land when you can eat from non-poisoned land.

I like the idea of having a barrier between your raised beds and the icky stuff. 

I think 3 feet high is a good height.  Due to my recent exposure to sepp holzer I might be tempted to up to five feet and plant in the sides.

Human hair:  I probably would avoid this.  Too much hair "product" issues that I wouldn't want in my soil.

But!  Lots of wood and sawdust and topsoil and good, organic compostables sounds like a recipe for excellent success!  Keep in mind that while I am a huge fan of hugelkultur, that I probably wouldn't want to mix sawdust into soil - it would rob too much nitrogen. 

>Toxins and the like just give me the willies.

Some of them give me the willies, and some of them don't.  I've had years of chemistry education and solid training in chemical and radiological safety, and I learn more all the time. 

Anything is toxic at some point, even oxygen.  Even pure water.  Even nitrogen (enough of it is a narcotic!).

Compost microbes can break any bond between C, H, N, O, S, and/or P, unless we're talking pure carbon, which isn't toxic.  Compost systems buffer away any pH or redox toxicity.  They even handle some heavy metals, like Cr, in respectable quantities (so it's OK to compost leather goods).

The only hair products I can imagine that a compost pile would not break down are mineral pigments and simethicone.  The only health problems I'm aware of from siloxanes are mechanical effects from implants (basically blisters from internal rubbing) and toxicity from reactive silanes, which aren't present in cosmetic-grade simethicone.  Pills of it (Gas-X, Phasyme) have been taken by huge numbers of people, regularly, for a very long time, without problems. 

Long story short, I'm not worried about any but a small class of industrial chemicals making it through the composting process with their toxicity intact.

I don't trust compost to break down halogenated hydrocarbons, like PCBs and dioxins.  It can't handle so very much B (which means I go easy on the corrugated cardboard and never add briquette ashes) or Cu (nix on any blue-dyed paper goods that burn with a green flame).  And I don't trust it for the nastier heavy metals, like Pb, Hg, As, or Cd.

At a yard sale, I found a book about trace elements in agricultural soil, which showed in tedious detail how high pH and competition form Ca ions would prevent uptake of other metals into roots.  It included peer-reviewed studies where lime was effective against lead and mercury contamination, among other heavy metals, as long as enough Cu, Zn, and Fe were added back to keep the plants healthy.  But that will only be a back-up method.

>up to five feet and plant in the sides.

Young children will be working here, so the top of the 5-footers would be out of their reach...which could be a good thing.  Well worth considering.

Thanks again!

The school seems to have almost-decided on a location.

There is a temporary 0.1 ha plot (50 m x 20 m) slated for mixed-use open space, that will have to accommodate parking and a play area.  As development of that block continues, a nearby vacant building will be demolished for a slightly larger yard, at which point the old yard will be cleared for new construction.

That means everything will have to be moved within a year or five, and the bulk of it will have to be a large open space, surfaced for heavy foot and occasional auto traffic.

For three to nine months before the school opens, the space might be available as a community garden.  During this time, I have been warned not to be too flagrantly unconventional. 

As your previous suggestions pre-figured, there will have to be heavy emphasis on climbing vines and containers.  I imagine a large, wavy or zig-zagged container could serve to mark diagonal parking spaces along one edge of this temporary yard.  I think some worms can be grown on local, gratis inputs in part of that open space.  Enough of the children's parents fish and/or raise chickens that they will find a use.

There is no budget for containers (or for much of anything else).  Scrap wood seems like the most sensible material, especially if it will all be demolished before it rots.  I think lots of rot-resistant timber is put in the landfill around here, maybe I can use some of that.  I think there are plants that would spill down over the planters, for the sake of aesthetics.  If I can find enough cuttings of a tree that doesn't compete too greedily for water, I might try one or two baskets of living saplings, filled mostly with mulch until the grafts gain some strength.  I think half a tire might be a suitable pot for such a contraption, until it can be moved to a permanent home.

There is a vacant lot on the next block over, 1.2 ha of irregular shape.  I hope to contact the owner about gardening in it temporarily, until the school gets a permanent plot or the real estate market improves.    Wish me luck.

I would like to do something before winter (e.g., scatter some seed to build up biomass over the rainy season), but I don't know how safe that soil is and am certain the school won't use it in the long term.  The possibilities will open up a bit when there is a key to the fence, and I can start ordering wood chips.