Urban self sufficiency food systems -- feedback wanted after my first round of trials

My group is trying to develop and trial food systems for a sustainable and independent Littleton CO. We hope to help others implement these systems for food security once we get good at them. I would really like some constructive criticism to reign in my inexperience. Here are my goals and ideas for reaching them for each system, and some questions afterwards. Scattered through my other threads are bits and pieces that will go into these.

We will continue experimenting till we reach our goals, or until wiser minds convince me that the goals are impossible.

System one.

System type:

Intensive container type system. 500 square feet per person.

Placement: for use near houses, on contaminated land, tight sites, rooftops, and pavement.

Inputs:

Cost: less then 500 dollars to build initially.

Fertility: Designed to capture and utilize as many available free nutrient sources as possible in a worm bin, which is the heart of the system. However, can eventually thrive on the sole input of some ground rock minerals, and the manure from the goats and chickens system into the worm bin. Should generate a substantial amount of nitrogen for itself.

Water: The water that falls on the area (15 inches or 4675 gallons in an average year) and another 4675 gallons from 500 square feet of catchment, i.e. roof area. However, to account for drought years, I'd like to design the system to use half that, if possible.

Materials: Mostly salvaged. Probably a new piece of greenhouse plastic every three years or so. Salvaged materials if possible.

Seeds: It should produce most of the seeds, new animals, etc. it needs.

Yields: 250 pounds of vegetables per year, especially leafy greens. (For this purpose, potatoes, sweet potatoes and other starchy roots do not count as vegetables.) 4,500 grams of protein a year, ideally from fish, if we can make this work out. 800 calories a day, mostly from potatoes, sweet potatoes, or some other starchy root.

Design ideas: potato and sweet potato towers, worm bin, aquaculture of some type, mealworm or other invertebrate production, wicking beds and buckets, aquatic crops, minimally heated frames or hoop house, shade structures.

System two

System type:

Semi intensive in ground gardening. 750 square feet a person.

Placement: community farms/ gardens, urban lots, greenbelts.

Inputs:

Cost: very low. Initial seeds, tools. No ongoing costs.

Water: the water that falls on site, concentrated into half the area.

Fertility: very little inputs, even in the establishment phase. Mostly rock minerals to balance soil, with continuing inputs to balance continued sewer use until that can be rectified. Should be able to produce all of its own biomass and nitrogen. Eventually, only inputs from the perennial/ animal system.

Materials: ideally, very few. Some fencing if necessary, low tech watering devices, a movable cloche or row cover.

Seeds: generates its own. Uses seedlings started in system one.

Yields: 100 pounds of vegetables a year. 1000 calories a day, mostly from root crops.

Design ideas: simple plastic catchment mounds to divert water into sunken beds. Rock and self generated mulch. Herbaceous perennials and annuals. Dryland tolerant crops. Deep rooted, nitrogen fixing cover crops. Minimal digging. Potato trenches.

System 3.

System type

Animal and perennial crops system. 500 square feet a person. 4 chickens. Maybe a goat per every ten to fifteen systems, otherwise more chickens. Fruit trees, hazelnut bushes. Greywater and humanure beds.

Placement: near houses, some parts on community farms, open space.

Inputs:

Cost? What would be the minimum for this system?

Fertility: Greywater and humanure from one person. Rock minerals to balance soil. Bulk of feed for animals from farm system.

Water: ditto and rainfall; drinking water for the animals from rainwater catchment.

Seed: self regenerating.

Materials: some building materials, animal care items.

Yields:

Eggs, milk, fruit, nuts. Makes up most of the shortfall in human nutrition from the last two systems, though there may still be a small calorie and protein shortage. Animal manure to system one. Humanure and greywater fed comfrey and other biomass to system two. Some firewood.

Design ideas: greywater catchment, dwarf fruit trees, hazelnut shrubs, goat and chicken brows, mulch for critter production, comfrey beds for humanure recycling.

System four:

Farm system.

The details of this a vague; it is the only system I will not be trialing. Small farms and ranches located out of town, a few acres per each town person. Provides the living of the farmers, the animal feed for system three, and any shortfall in human diet. Also provides the bulk of the firewood, building materials, and cottage industry feed-stocks for the town. In this climate, probably dry land silvopasture on some sort of keyline system. I will have to take this system for granted in my system trials.

One big question: in my designs, how should I roughly account for the minerals currently exported in produce, so that I can provide just enough replacement, simulating a closed system?

What of my goals needs to change in the face of reality? What ideas do you have to help meet the goals?

Lots of good ideas there. Let me think........
......low rainfall area. Thus traditional container gardening won't work well without bringing in water. But wicking containers are something I would definitely try. They use a lot less water, but to require more in initial set-up and maintenance.
......Colorado. Can you legally collect rainwater there and divert it for garden use?
......chickens and pigs are the best converters of garbage/waste-to-food. Plus they produce manure that would be valuable in your closed system.
......are greywater or humanure legal in your area? If not then you may not get away with using them in a public project.

Labor may be your limiting factor. Producing large amounts of food takes a lot of labor. It also takes money in the form of equipment, supplies, and infrastructure. Plus of course you would need some people already knowledgable with agriculture on your proposed level.

In my area I've been teaching and encouraging food production on the gardening level. I find that labor is the biggest problem. Most people don't want to put that much effort into it. After a couple of months they go back to buying everything from a supermarket, which is far, far easier. Plus often cheaper in the long run for a small gardener. Afterall , the tools, fuel, irrigation supplies (hoses, containers, tanks, pools), soil amendments, pest and disease controllers, seeds/plants, food storage of the surplus, and doctor bills to treat the cuts, sprains, aches & pains can all cost more than the value of the vegetables eaten from the garden. Oh, there are ways to get around these costs, but most people aren't willing to scrounge, home-make, or make do.

I'd love to see everyone who is capable having a food garden. Even little ones would help. But after working for 10+ years to try to get people interested, I see very, very few people willing to stick with it. And I really mean few!!! I hope you see better results than I've had.

I believe that urban environments are inherently unsustainable. As far as I can tell, they only exist because we have been burning through 500 million years worth of stored sunlight as if it would never run out nor become harder to mine.

It takes about 1/4 acre of farmland to feed a person for a year. So that would be 22 of those 500 square foot plots per person. If the average household has three people, then it would take 66 of those 500 square foot plots to feed the average household.

Littleton is already importing it's food from outside. Might as well continue doing so until either the oil runs low or the currency crashes.

Hello Su and Joseph,

I should have explained that I'm thinking, as Joseph pointed out, that oil will run out and the currency will crash; I'm just not sure on when. This is a sort of pie in the sky idea that as it happens (I'm thinking that it will happen slowly; more and more people getting knocked off the ladder) groups like mine can have got enough experience and membership to step up and solve the problem. Probably will not happen. I agree with Su, getting people to stay interested will be difficult, but if people are actually hungry it might help (or not!)

Joseph, two points on area: A. supposedly the biointensive people can grow all a person's food on 1000-4000 square feet: B. in my plan, each 1500 square feet area per person will be subsidized by several acres of farmland providing animal fodder. This influx of nutrients solves the protein problem, which is the hardest problem to solve in a tiny system. I'm thinking that even in a serious crash, there would be the ability to gather some type of hay from the countryside a few miles away.

Also, cities of a smaller size have been around for 5000 years or so, but I agree that cities of the type of the Denver core are impossible to sustain. The Denver core will be an endless glass quarry though . Interestingly, in Littleton each resident actually has 8000 square feet of total space. That counts roads, roof, etc. but in a really serious crunch most secondary roads can be utilized. Of course, we could get into the problems of looting hordes, etc. etc. but I'm hoping that the powerdown will be slow and of the Cuba variety. I (personally) don't see the point in preparing for the Armageddon variety, since anything I prepared would probably fail in that scenario.

Finally, let's say things don't fall apart. I'm still crazy enough to try to build a better world. Whether a better world is possible in the city, though, is anybody's guess! I imagine that most people will continue importing food if they can. But it would make me happy knowing that it is possible.

Su, technically, rainwater harvesting is not legal. But if one lays down a sheet of plastic next to a bed, and the rain flows into, nobody will stop you. And if a gutter ends up in the garden, same thing. Even if it ends up in a barrel, so long as neighbors don't complain, nobody bothers you.

I'm hoping to design the system without the greywater and humanure for now (except the ones in my back yard) until either the codes change or they become irrelevant. Thus the question on how to simulate a closed system. In other words, an open system designed to close at some point.

I'm thinking that all the containers will be wicking containers of some sort. I'm going to use the standard food grade white bucket; endless amounts of them are thrown away from shops, etc. It does not take much work to cut the lid and jam it half way down the inside of the bucket, insert another salvaged container or a chunk of brick to support it, and insert a wick.

I realize that containers are not idea for our climate. However, since our soil is highly alkaline and hard as a brick, and there is vast expanses of paving, and some soils are full of lead or other problems, it will be easier in some places to use containers. Especially if we take over the empty back half of a parking lot.

In any event, we will be testing some sort of system this spring and very carefully measuring inputs and outputs. It should be interesting anyway. I'm willing to expand the area per person to 4000 square feet, since that is half of the total land area per person here; the other half would be roads, pitched roofs, etc. (After we broke up minor roads, empty parking lots, golf courses, city parks, greenbelts, and surplus structures.)

I am very interested to see each of these systems in action, Gilbert. I think any food-growing experiment is worth pursuing.

I've cleaned up the ideas for the systems a bit, and done some back of the envelope, wildly optimistic calculations that would seem to indicate that the goals are achievable. Of course, the proof is in the pudding! I aim to have working experimental systems for one and two by this spring.

System one.

A system to use on pavement or contaminated soil, thus above ground and containerized; 500 square feet per system; using only waste product inputs once established; (though there may be a high level of waste inputs); hopefully using a very minimal level of energy; hopefully using only 9000 gallons of water a year; (obtainable off a thousand feet of roof in an average year); providing all a person's vegetables, (250-300 pounds a year, not counting potatoes and other starches); a quarter of a person's calories (292,000 a year); a quarter of a person's protein for a year (4,500 grams); and not costing more the $500 to build initially, thus ruling out fancy high tech stuff. (Using fish to get the protein would need a 130 cubic foot pond or tank; 3 feet deep, 6 feet on a side.)

(Potential elements of the system: Wicking containers, potato towers, aquaculture, worm bin, etc.)

System two

A system to use a vacant lot or other land, without a reliable water supply; 1000 square feet per system; using only mineral supplements to balance the system; no imported water or organic matter after the first year, so only using rainfall; using no or low dig methods; producing supplemental vegetables and half a person's calories for a year; using less the 500 dollars to establish.

(Potential elements of the system: Rock mulch, dew catchment, potatoes, perennial plants, no till, cover crop experiments, sunken beds.)

System 3

A system to keep a few chickens, possibly goats (on multiple connected systems), fruit trees, and recycle humanure and waste water; using 500 square feet; receiving inputs of waste and chicken feed; recycling nutrients into comfrey which can be dried and used as fertilizer to cycle back into systems one and two, closing the loop; making up most of the short fall in calories and protein.

(Elements of system 3 are illegal for now, so I will not work on it until things change.)

System 4

A farm system outside the city to raise chicken and goat feed, and any shortfall in food.

So here are some more ideas for my system one.

First, two questions.

1, is there any elements other then the ones I list below that you think would be valuable?

2, has anybody had any practical experience with the various elements I mention? If so, could you please tell me how they worked? Even if your climate is not similar, I would be interested. Particularly small scale aquaculture as opposed to aquaponics, potato towers, and wicking buckets. For the wicking buckets, I am especially interested in what potting mix you used, and what fertilizers.

I think there will be five main elements for my first round of experiments with system 1.

First of all, potato towers. I will be screwing together pallets, which I can get a lot of for free, and lining them with black landscaping plastic, which is quite cheap. I'm not going to worry about pesticides on the pallets, since I get them from a used computer warehouse that gets deliveries from within the country, and also because of the plastic. I will fill some with wood chips, and some with leaves, and in each I will include some soil. I will also fertilize each with a complete organic fertilizer. If I can get straw or hay cheap, I will use that, since I think it would work better. I found another permie who got a yield of 160 pounds from 30 square feet of tower (base). I'm only going to count on 120 pounds per 30 square feet, so 210 square feet will be used for the towers. Like most of the other things, the towers will be watered with fish tank water.

Fish. I am going to include tanks of fish to raise the protein for the goals. I'm still trying to decide which kind of fish would work best. Tilapia need a little too much heat. Instead of plumbing them to aquaponics beds with a pump, I will be replacing 3 percent of the water each day and using that water for the plants. The tanks will be 975 gallons total to raise 90 pounds of fish, 45 pounds of which will be edible matter. The tank will cover around 45 square feet if it is three feet deep. I will build a very cheap and simple lean to plastic cold frame for the fish tanks against the west corner of the house. (Though I will still probably have to supplement heating.) I will be purchasing feed for the fish, but also experimenting raising azolla, worms, and daphnia for them. I will use a solar battery powered mini fountain to aerate the tank. And I will be using rafts or wicking containers to grow some vegetables right over the tank. 3 percent of the water changed out per day comes to about 30 gallons a day, which will equal my desired total water usage of 9000 gallons in 300 days. Since I don't have 300 growing season days, I will be able to use some non fish tank water to irrigate and still stay within the limit. I'm interested in experimenting with algae cultures for daphnia, wood ash to provide the nutrients for azolla, and worm castings to provide the nutrients for duckweed.

Worms. I will be including a worm bin to break down recycled organic matter and dead plants, including a lot of coffee grounds. I will probably use our rabbit manure, and may build the bins right under the hutches.

Wicking buckets. I will be turning free five gallon buckets into wicking containers for the vegetable components of the project. I will cut the lids down until they fit half way down the bucket, put a recycled plastic container underneath the lid to help support it, put the wicks through the lids, the soil above the lid, and insert a recycled water bottle through the lid to fill the reservoir through, primarily with fish water. I will be trying out four different potting mixes; a free draining mix of bark or wood chips, peat, and perlite; the same with added biochar; a more compact mix with peat, compost, and perlite; and the third mix with added biochar. Since I will be growing the same vegetables in each, we will be able to see how they do compared to one another. Also, I will be adding complete organic fertilizer to each, and in the free draining mixes I will roll the fertilizer into clay balls to insert into the pot.

I may also experiment with putting loops of copper wire around the plants in some pots to see if the electromagnetic charge boosts the yield.

Sweet potato towers; I will be building brick raised beds for the sweet potatoes, to heat the soil and speed growth. I may try the greens as well as the roots.

All elements will have simple hoop type structures to support shade cloth, row cover, or tarps against hail, depending on the time of year.

Anything here too far out? Anything you would do differently?

Just for ideas, Windward community in WA, is doing calculations on how to produce basic human nutrients... fat may be the limiting factor. Duhon's 'One Circle' is referenced here... I assume you've already checked it out.

http://www.windward.org/notes/notes70/walt7009.htm
and the Note on how many pigs for how much lard :)

Also, Will Bonsall's book is very interesting, in providing all his family's nutrients from his homestead... a lot of experience.. been there 40 years :)

I hope you have confirmed successes with the spud towers.. those I know who've tried it have been disappointed... but a few spuds from 4 sq ft of asphalt is better than nothing :)

And I agree wholeheartedly that the knowledge and experience may turn out to be literally life-saving when hunger has provided the willing labor :)

Hello Nancy,

Good suggestions!

I did read One Circle, and got a lot of inspiration out of it

I will definitely look up Windward and Will Bonsall, since I have not read either on that topic. I have read Will on some seed saving stuff.

I'm using some animal products with outside inputs, and some waste stream fertility inputs, which (I think) will make it easier to balance both the diet and the soil fertility in a small space then it was in One Circle/ Biointensive projects.

I hadn't thought about fat intake very much, and since I am a Weston Price fan, I suppose I should do some thinking along those lines.

About the potato towers; there is a post here on permies where they got 160 pounds. However, I have no confirmed successes with Irish potato towers, and my sweet potato tower only yielded ten pounds out of 12 square feet.

Do you know the specifics about the failed potato towers? Soil/ mulch fill type, varieties, location?

Overall, I'm actually expecting a fairly high failure rate on all my experiments. But I think that the most important thing we can do now is experiment and, above all, document. I like to think that my experiments, with whatever result, will add to the great pool of open source knowledge that permies have become. I am so disappointed by researching many topics, especially food self sufficiency in a small area, and finding so few actual documented experiments, particularly in my climate area.

As you pointed out, this localized knowledge will be very valuable in building a sustainable future. Even if just one of my ideas works here and somebody picks it up, that will be a success.

Hopefully the fact that I am posting here will help me to document what I am doing on a regular basis.

A side note on those inputs- I've come to the conclusion that using broad acreage outside of towns and cities to provide easily stored inputs harvested once or twice a year, or once or twice a decade, to support intensive, high yield systems in relatively densely populated urban areas is the way to go. (Lumber, charcoal, hay, etc.) Not that people shouldn't live in the countryside; somebody has to manage those forests and fields. But most people are in the city, and it will be difficult to change that, especially as energy runs out. We will have to live with the infrastructure we have and do the best we can with it. And I think that lightly harvested meadows, forests, rivers, and lakes will be far better for wildlife and the ecosystem then actually growing human food on large, extensive acreage.

This is not a tower, but an experiment in growing in lined cages... up here in the wet side of the PNW (Windward is on the dry side :).

http://www.nwedible.com/heavy-duty-potato-cage-results/

Probably OT, but John Michael Greer at his Archdruid Report blog, is serializing his upcoming book (Retrotopia) on theoretical life in 2065 in the US...no particulars about 'agriculture', but how cities/towns might morph to cope ...just for fun :)

nancy sutton wrote:Just for ideas, Windward community in WA, is doing calculations on how to produce basic human nutrients... fat may be the limiting factor. Duhon's 'One Circle' is referenced here

In the One Circle examples, which are vegan, sheer lack of calories is the biggest problem, along with lack of a few key nutrients such as iodine and B12. In my opinion, animals are needed in a survival situation to turn materials inedible by humans into crucial human nutrition. Animals who accumulate fat, such as chickens and pigs, are needed, along with ruminant herbivores who turn cellulose into edible products.

Gilbert,

This is a fantastic idea and I wish you great success.

I'd maybe emphasize season extenders (hoop houses, cloches, etc.) a bit more. Fresh veggies in the winter would be a big benefit in a cold climate.

You and Sir Albert Howard, Tyler: "Mother earth never attempts to farm without livestock."

And re: Duhon, I remember being surprised that calories were the limiting factor, and not protein. Windward has detailed calculations about fat per person requirements, lard per pig, how many pigs per person, etc., etc. :)

Re: the calories, I recently asked Toby H. in an on-line Q&A, about the permie emphasis on fruit trees/bushes providing a lot of the required carbo/sugars, but he fell back on the need for the root veg's. Hmmm..... guess starch trumps sugar in the calorie competition...the old 'meat and potatoes' diet is pretty healthy, after all :)

Hello Nancy, Tyler, and Steven,

Those are pretty low potato tower yields. And they used rotted wood chips, just like I intend to do. Well, we will see.

I'm in the camp that holds animal products to be indispensable. Maybe not a large amount of them, but some. At least for a lot of people. I'm sure some people do well on vegan diets, but I don't want to design one because A. it has already been done, and B. it wouldn't suit everyone.

About the fruit not being a good source of calories; I was just reading up on that. Apparently, the calories in fruit are mostly fructose, instead of glucose, and we process glucose better. Also, there is just too much water in most fruits and vegetables to make them good calorie sources. You would have to eat too many pounds of them per day.

Apparently, even turnips, carrots, and beets don't work for a staple calorie source, according to the biointensive folks. They use potatoes, sweet potatoes, and parsnips as the main root crop staples, supplemented with grains (which are even more dense but take too much space.) I wish I lived in the tropics where breadfruit and plantains grow on trees!

I'm hoping that my animals will (eventually) feed on waste products, and that (eventually) those waste products will be the only inputs to the system, until/ unless they run out, in which case feeds will be grown on farms outside of town. I remember hearing of a tropical permaculturist who gathered huge volumes of waste paper and stuffed it into a buried garbage can with the bottom knocked out. The termites would find it, and every few days he would scoop out a big shovelful of high quality protein- for his chickens.

I am planning to include a lot of season extension. So far I have found that Eliot coleman style unheated greenhouses are fairly tricky to run, or fairly tricky to run here in Colorado, I'm not sure which. But I'm working on it. And I will have to build some sort of cover for my fish. Also, hail is a big problem here, and I want some sort of easily moved cover that I can quickly throw over the whole thing as the thunderheads move in. It would have to be very easy, since we can get a (potentially) damaging storm every week, and I would soon get tired of something elaborate for so many false alarms.

nancy sutton wrote:the old 'meat and potatoes' diet is pretty healthy, after all :)

As long as you also eat plenty of leafy greens for vitamins and minerals! ;)

So now I find that tilapia are not so great from a nutritional standpoint, and that the only super healthy fish one can do in aquaponics are trout, which are also one of the hardest fish to raise in aquaponics, at least for beginners.

But if I'm doing this to replace the usual junk that people eat, I have to make sure it is all top notch!

On a related point, I'm using the book "Eating On The Wild Side" to choose varieties and preservation methods that are particularly high in nutrients. No point doing all this work to grow a lot of water!

What about Bluegill? I had some for awhile in my aquaponics system and they did great until I got Catfish who died and killed everything else.

Hello Tyler,

It is hard to find Omega 3 ratios for less commercial fish like bluegill. It looks like the only fresh water fish that might be positively unhealthy (barring contamination) is Tilapia, though others say it is only a function of how they are raised. In any case, Tilapia need a lot of heating in this climate. The average air temperature of our warmest month is 72 degrees, and as with everything in Colorado, averages of the means of fairly extreme extremes.

So far as my research has gone, any fresh water fish is negatively less healthy then salt water fish (again barring contamination) except for trout. (Trout have as many or more omega 3s as salmon does.) But negative unhealthiness is much less a concern for me then positive, especially in the early stages of the experiment.

So, a hardier cold water fish like bluegill or bass or perch might be a good idea to start with, until I get experience enough to do trout and see how the water parameters hold up.

Then again, I'm planning to have several smaller tanks instead of one enormous 900 gallon tank, to minimize the consequences of leaks or other disasters. Maybe I could try a could multiple different types.

I'm thinking I will use defunct chest freezers as the fish tanks, and dress them up somehow to look less scrappy. Old chest freezers are supposedly available for twenty bucks a piece, and I could get enough food safe interior paint for ten of them for 250 dollars. So 450 dollars for 1050 gallons of tank, assuming the freezers are each 15 cubic feet. And there goes almost my whole budget for the project.

Or I could not use the paint and hope the plastic lining of the freezers don't leach anything horrible. Or I could line the freezers with pond liner of some sort. EPDM pond liner is about a dollar per square foot, and a lot of it would have to be folded up and wasted to fit the freezer. Or I would have to cut and glue it, which would introduce leaks.

I'm not sure yet.

For urban gardening, how about incorporating a rabbit hutch as part of the system? They turn garden waste into fertilizer very quickly and can either provide meat or fiber, depending on the type of rabbits you get. Rabbit manure is a cold fertilizer and can be put directly on the garden without composting. Although, folks do recommend that you not put it on greens or other plants that you intend on eating raw that might touch the manure. It was something about disease transmission, but I forget exactly which or what but you'll be able to find out if you're interested, no doubt. In those situations, they recommend either composting or manure tea, I believe it was. Myself, I just toss it on the garden, dig it into the top ten inches and put it around all the fruit trees since bunny berries (rabbit manure) is the only fertilizer we have.

Also rabbits are very quiet and aren't stinky, so they fit right in with an urban garden.

Actually, we have rabbits. And I will probably be using the manure as an input in the worm bin.

The reason I didn't include rabbits as a food source in my initial plan is that my family does not want to eat rabbits. (Cute factor.) So I would not actually be able to test that out.

Also, with all the pet rabbits we already have, I couldn't really get more meat ones for the system. (I wouldn't kill them, but I could at least see if I could grow enough poundage.)

Anyway, you have a good point, and I will probably plan on using rabbits in later versions. As I think about this, I see more and more advantages.

Instead of buying fertilizer for plants, buy hay, convert to rabbit manure, convert to worms, convert to fish, fertilize plants with fish and worm waste.

Instead of watering plants, "water" fish and then water plants.

Thanks for pointing this out.

Just some of the numbers for closing the alfalfa - rabbit - worm loop--- http://plenty.150m.com/IBS_ECOSYN_01/IBS-ECOSYN-01.html

Thanks for that link! It was very interesting.

One thing I would point out is that a lot of people would say that alfalfa is not a complete diet for rabbits. In fact, some people say to avoid any alfalfa being fed to rabbits! I find it irritating that ANY opinion can be found on the web, which is one reason I will be actually running these experiments.

But I think the point would be valid if various other herbaceous plants were fed to the rabbits instead of alfalfa.

With the addition of some minerals to keep fertility balanced, the empty, dryland plains around Denver could easily provide the input for hundreds of thousands of small, intensive systems in the city.

One important point about all this is that for small systems of the sort being discussed to work forever, it is important to start recycling human waste. Otherwise, the systems will run down. Humanure composting is not legal here, and besides, I would be hesitant to advise the general public to do so in any case, due to liability issues. But long term, my system four components are absolutely necessary.

A friend of mine had a very cool setup with the rabbit poo going to red wiggler worms and the worms were food for her chickens. She also sold worm castings and vermicomposting setups.

I've been doing some more research on potato towers. It looks like the keys are: keeping the soil cool and moist, or potatoes will stop forming; using the longest season variety you can get, since early season varieties stop making tubers no matter how much they are hilled; and, making sure there is plenty of fertility to keep things going.

I will probably use white plastic inside my pallet bins to keep things cooler. I might also add a layer of straw for insulation.

Also, as with many things, I suspect there is a critical mass required. I imagine a little skinny tower will do worse then in ground planting, and a hefty tower will do better. Less fluctuations of temperature and moisture, and more room. Each of my towers will be between 50 and 70 square feet at the base (based on an octagon with sides between three and four feet long, the size of a standard pallet, and over four feet tall.

Something I see that could easily put gum in the works is availability of seed. Saving viable seed requires much more knowledge than just leaving the last few plants in the row. Maybe 1 in 10 (or whatever ratio it needs to be) producers soecialize in seed production. Thats the beauty and challenge of farming, the vast amount of expertise it takes to be good at it.

Hello Darin,

Yes, seed production is difficult, though not impossible at this scale. I've done a lot of reading on it, and a little hands on work.

Potatoes have to be bought each year for best yields in any case, though in a really primitive situation, so long as you can store potatoes, you can have potatoes next year, just less per seed tuber. There is a complicated set of protocols to follow to avoid picking up viruses over the years. Sweet potatoes the same way, but they are easier to save without picking up disease.

Tomatoes, lettuce, beans, peas, peppers, eggplant, and most grains are very easy to save, and could be done within these systems. Squash family and most of the roots are harder, and require more space. Brassicas, corn, and carrots are very hard, and require a good bit of expertise and quite a bit of space.

For now, I will be buying seed. I will be trying to save seed from all the crops on the first list to start with.

For the more difficult crops, you are probably right; somebody would have to specialize, or producers would have to team up. The nice thing is that that harder crops often produce thousands of seeds, which could be saved for many years before they have to be grown out again. To avoid inbreeding depression, for instance, one would have to raise 40 cabbages. This would provide hundreds of thousands of seeds. With some reusable silica gell and a root cellar, this could last ten years.

Hi Gilbert
You've already done some serious research, and have acumulated a lot of knowledge. Good on you. I much commend your project. We will change or be changed in the not so distant future.

Hello Darin,

I do have a lot of theoretic knowledge, but not too much hands on experience; thus the experiments! I have piles of often contradictory or irrelevant or out of place ideas to try out. It will be interesting to see how things turn out!

Concerning the aquaculture, carp seem like the way to go. They eat a variety of things and are very resilient.Different kinds can fill different niches.
Lots of cultures eat and love carp, just not this one...I want to grow out Koi in any system I set up, because you can sell them to the pet trade for more than you could get in any theoretical fish market, at least until food gets scarce.
On a similar note, I don't want to eat invertebrates ,but plenty of people do, and crawdads have been tried as aquaculture animals.

There is a guy using the freezers, he has the special paint for sale at his website, and good instructions.
I am wondering if surface bonding cement could work on plastic, it was developed for use on masonry cisterns and the like.
Even if it couldn't work directly, perhaps line the freezer with backer board, or even build an inside mold and pour cement, using the insulated walls of the freezer as a leave in place outside mold.


I see rabbits as a way of turning tree hay into fertilizer. I say tree hay in particular, because it seems easy to aquire, harvest and even store.
In fact , one could get paid to trim a tree.

Now tiny Nigerian goats might be better in terms of maybe providing food in the form of milk fats,but they are notoriously parasite ridden and hard to fence.

Leaves For Life has some interesting ideas on making green leaf nutrients primary nutrients for humans. I like the idea of feeding myself off of dried mulberry leaves, or making a "tofu" from alfalfa leaves.

I would like to bring potato towers indoors,growing potatoes all year round,if it is feasible.

I wonder if mushroom would grow through holes in the side of a bucket full of rotten wood chips while potatoes grew inside.

It seems to me, that if someone is intending to abandon industrialized food production, that it may be advantageous to them to also abandon industrialized seed production.

I believe that the vast set of rules and "best practices" that have arisen around seed saving are rules and practices that apply to industrialized (centralized) production of already highly-inbred seed. As far as I can tell, those practices have little to do with non-industrial agriculture.

As an example: I am certain that genetic testing would show that there is more genetic diversity in one ear of my Harmony Grain Corn than there are in 100 acres of industrialized corn. Many hundreds of varieties have contributed their genes to my corn. The genes have been shuffled millions of times while they have been in growing on my farm. The sort of diversity that I am working with works extremely well on a small scale and with localized populations.

I do not care about "isolation distances" or "plant purity", because if my seed gets "contaminated" by another variety, then I have introduced genetic diversity, and I have opened the possibility for "hybrid vigor", and reduced the chances of "inbreeding depression". I give my plants plenty of opportunities to get contaminated. With my established varieties, I aim for about 5% contamination per year. When I first start growing a new species or variety, I aim for 100% contamination.

I grew a crop of bok/pac choi seed this summer. On 160 square feet, I grew enough seed to plant 24 acres. The seed is likely to remain viable for a decade. I ended up letting about 80 mothers go to seed.

Once I discarded the "industrialized mindset" regarding the growing of seed, then seed saving became trivial. The basic rules of seed saving and plant breeding are: Plants make seeds. Offspring tend to resemble their parents and grandparents. That was sufficient information for illiterate farmers to bring us all the gloriously domesticated species that we enjoy today. It is sufficient now for anyone to become a really good plant breeder. I really recommend ditching the idea that we can make mistakes in plant breeding... Let's not worry about purity, or pedigrees, or stories, or isolation distances. Let's focus on what matters right here, right now: Growing seeds that are adapted to our current conditions in our current time. Sure, I didn't like it this summer that a lady contaminated my sweet peppers with hot pepper pollen. Oh well, I get to taste the peppers next summer and chop out the hot ones.

Cloning is a process that is very prone to propagating disease, both because once a pathogen overcomes the defenses of one plant of the clone, it overcomes them all, and because duplicating a clone often duplicates it's diseases and pests. Pollinated seeds are much less likely to pass on diseases and pests. Some potatoes make pollinated seeds. Tubers do not have to be stored from year to year. I have germinated potato seeds that are decades old. In my garden, I make a point of growing only those varieties of potatoes that make seeds abundantly. Again that is exactly the opposite strategy that industrialized agriculture pursues, but for me on my farm it seems like the only prudent way to grow potatoes.

True Potato Seeds:


I attend seed swaps during the winter. I'll accept any locally grown seed that someone wants to trade with me. By doing so, and planting their seed with mine next year, I have increased my effective population size to be as large as the sum of all of the plants growing in all of our gardens. If I plant seed from previous years crops, then my population size expands to include all of the parents from previous years as well.

I really like your approach to seed saving, Joseph.

Hello William,

Some good ideas there.

Carp are very hardy, but their nutritional profile is not as good as some others. I'd like to raise trout, but they may be too finicky. On the aquaponics front, I researching something called iAVs; basically using a sand bed instead of gravel.

Unfortunately, goats are illegal here.

Tree hay and edible leaves are two things I'm interested in for systems 3 and 4. I wonder how one could efficiently store tree hay?

Hello Joseph,

I also like your seed saving ideas, especially for system 4 type areas.

On the small scale of system 1, wouldn't it lower yields a bit for some things, especially for potatoes?

For instance, with the potatoes, let's say 20% of the new true seed varieties had very low yields. If I'm only going to have 30 super pampered tower potato plants total, wouldn't that really cut into my production? Would it work better if the seeds were planted out elsewhere, and evaluated, and the best ones used as clones in the intensive system until yields dropped, at which point another batch of seeds could be raised?

Also, for now, with a field of jack-o-lantern pumpkins next door, I would be worried about loosing all my strains of pepo squash. I have zucchinis that actually taste good and do well. How would you keep the pumpkin genetics from getting in?

Finally, last year my community farm planted 500 land race tomato plants. I ran into some trouble with them, and could use your advice.

Because of the different shapes, colors, and levels of firmness, my volunteers couldn't figure out what was ripe. (Note that these people were fairly inexperienced gardeners.) So I had to do a lot of the harvesting. The different shapes and sizes ended up damaging more tomatoes, and even for more experienced gardeners, resetting what we were looking for at each plant was more difficult. We sold some, and the people wanted to know what varieties they were, and we couldn't tell them. Also, since a lot of the varieties looked the same but tasted different, people were not sure what they would get.

I'm wondering how to make this more functional for next year.

Anyway, for tomatoes, lettuce, and quite a few other crops, I agree with you on the genetic purity question. But I'm just wondering about your take whether a tiny, intensively cultivated area in which every plant has got to count makes a difference, and what to do about crops where the cross could make them inedible (carrots, squash.)

Gilbert Fritz wrote:what to do about crops where the cross could make them inedible (carrots, squash.)

It's the same problem you face if your neighbor gardens, unless you somehow require everyone in town to plant the same variety of a given crop, which would be a super bad idea even if it could be implemented. If people want to maintain pure strains in a personal garden, they'll probably need to hand-pollinate and bag their blossoms, just as people do who are conducting plant breeding work., it seems to me.

Well, I don't really care if my neighbors edible vegetable crosses with mine. But a jack-o-lantern pumpkin crossing with my zucchini would be bad. As would Queen Ann's lace crossing with my carrots. Other problems might be chard crossing with beets; I might depend on getting roots, and fail to do so. But with tomatoes, say, not only is crossing rare, but any cross would be edible, so it is not a problem. The same for most greens, cucumbers, melons, and most brassicas.

My primary goal with plant breeding is not productivity. It is reliability. My goal is food security: Having a consistent supply of food year after year. Regardless of what the weather is doing, regardless of whether fertilizers or mulch are available, regardless of how distracted I get by family problems, regardless of the weeds. Industrialized agriculture chases the few percentage points of increased yield because they are worried about profits. I do not care about profits on my farm. I care about reliability. I care about consistency. I care about taste. I care about minimizing the cost of buying inputs. I care about not poisoning myself and those I feed. I care about aroma. I care about having interesting looking food.

The big danger with growing clones is catastrophic failure. When a pest or disease overcomes a particular clone's defenses, it overcomes the defenses of all members of the cloned group.

Yes, potato clones produce higher yields than potato seedlings. It also takes much more sophisticated farming and storage techniques to raise potatoes from clones. I can store a packet of potato seeds on a shelf for decades, and easily carry enough potato seeds in my shirt pocket to plant enough potatoes for a city. Breeding potatoes is just like breeding any other crop. When grown as genetically diverse landraces, selection is very quick towards those families that thrive under the local growing conditions and farmer's habits. With potatoes, I grow a mix of clones and seedlings. That way, I get the best of both worlds. If a clone ever succumbs to disease, bugs, or weather, then no worries, I have a hundred candidates waiting to take it's place.

There is a grower at my farmer's market that grows large quantities of beautiful vegetables: I consider this tomatoes to be tasteless, and hard. He douses his crops in poisons. He pays huge sums for crop protection chemicals and fertilizers. Sometimes I feel bad at my meager offerings. But then I smile. My tomatoes taste great. So what if they are the size of golf balls instead of the size of softballs? My cost and labor to apply poisons or fertilizers is exactly zero. Things are fine for him today while fuel is inexpensive. I wonder how he'll get along if the availability of seeds, poisons, and fertilizers is interrupted? For me, it would be been-there, done-that... Since I already grow my own seeds and don't use cides nor fertilizers.

I have no reason to believe that potato towers are a viable growing method, but let's assume that they are... I believe that long term, you would get better results by growing some percentage (say 30%) of the potatoes from seedlings... Because that would allow you to select for traits that thrive in potato towers. If I were growing potatoes in towers, I'd want to grow them in the city, with it's unique micro-climate and cultural practices so that they could be as locally adapted as possible. Local adaptation even happens to a specific grower's way of doing things. Some varieties of potatoes are indeterminate, and send out tubers all along the stems. Those would be the ones to select for growing in towers.



Pollination is a highly localized process. The mathematics deals with quadratic equations. So as the distance doubles, the cross pollination rate is cut to 1/4. Here's what that looks like in a graph of two patches of carrots. There is very little cross pollination between the two patches, even when spaced as closely as these patches are.


With carrots, one Queen Anne's Lace weed growing within a patch of 100 carrots produces about a 1% cross pollination rate: Unfortunate, but not a disaster. It's easy enough to see the off-types next year and cull them.


Weeding the QAL to a distance of only 15 feet strongly inhibits the amount of cross pollination:



In my garden, I don't worry much about keeping hold of strains. I am stewarding species. As long as I am growing moschata squash, I don't much care if it's a butternut, or a long-necked squash, or a pumpkin. It grows the same. It cooks the same. It tastes the same. I get about 5% cross pollination when different varieties of squash are growing 100 feet apart. I get about 5% cross pollination when different varieties of corn are growing 11 feet apart. I like those kinds of odds. Industrialized agriculture doesn't.

If you are worried about productivity of tomatoes, then they pretty much need to be picked at the first sign of color and ripened out of the field. Also, I always remove the stems from tomatoes while picking. That prevents the stems from jabbing other fruits. It also prevents people from looking at the stem and prejudicing the tomato because it wasn't picked today. If I wanted to take tomatoes to market and not lose a significant number of them in transit, then I would grow industrialized tomatoes: You know they ones. They have a texture and taste that approximates cardboard. To minimize transportation damage, I pick into flat, rigid, stackable trays, and don't handle the fruits from the time they are picked until they are at market.

My strategy for picking tomatoes is that anything with even the slightest blush of ripening gets picked and placed into a common lot with any other tomatoes picked that day. (I pick cherry tomatoes separate.) When people ask me what variety my crops are, I say, "They are my own variety that I developed specifically to thrive on my farm". The commercial farmer next to me never ever tells someone what varieties he is growing. He considers it a trade secret. The grocery store almost never tells people what varieties they are selling. I don't know why people that visit farmer's markets think that they need to know what variety they are getting. In any case, my clientèle have ended up being adventuresome people who are not afraid that today's tomato might taste different than yesterday's. That's the kind of people I like hanging out with. They like diversity in their food. I don't much care for picky eaters, and I am delighted if having mixed varieties keeps them away. And for canning purposes, any tomato pretty much tastes like every other tomato.

Lofthouse Landrace Tomatoes:


I think that the fear of inedibility has been greatly exaggerated by industrialized seed marketing companies. I grow 5 species of squash. All varieties of all species are edible as summer squash. I might not like eating pepo winter squash, but they are still edible, even if crossed.

I cull frequently. I don't adhere to the mindset that every plant counts. What matters more to me is diversity. I plant 300 types of beans. Some family types will do well this year that did poorly last year. I can't predict the weather, diseases, and bugs ahead of time to be able to choose which varieties to plant, but if I plant hundreds of varieties, then something is bound to produce food for me regardless. I am firmly of the mindset that a mediocre harvest every year is better than a great harvest most years and none in some years.



If you are interested in decentralizing the production of food, I'd like to suggest that you also decentralize the production of seed. I think that you'll get better results that way. If you are worried about productivity and efficiency, then it seems like food aught to be grown far away by industrialized machines that are very good at that sort of thing. Growing food in a de-industrialized manner is about as inefficient an activity as I can imagine doing. I don't grow my own food and seeds for the sake of efficiency or productivity. I grow them for the sake of food security and redundancy.

Jack-o-lantern crossed with zucchini is still an edible squash. The shape of the plant and fruit changes somewhat, but the taste and cooking qualities are approximately the same.

Hi Joseph,

Good points.

Are there any species that would would take more trouble with if you had less space?

I like your idea about starting 30% seedlings for potatoes.

Given their vulnerability, why do you think traditional people, especially in the tropics, did select so many clones? (Potatoes, bannanas, sweet potatoes, etc.)

Do you grow any pepo squash specifically for summer squash eating? I dislike many squash, even those specifically breed for summer eating, which is why I'm concerned about keeping my zucchini strain pure.

Also, my concern about the minimum amount of space to feed people, and thus higher efficiency, is due to the fact that I don't think people will be able to move out of the cities into the countryside to any great extent. Housing and all the other infrastructure would have to be set up and the big farms subdivided into smaller parcels. By the time people realize that this would be a good idea, we will not have the time and energy to do this. (And the government will realize it last of all, and keep propping up the big farms to avoid them breaking up naturally.) So we will have make do with what we have. And to boot, I see the individual pioneering farmer of the USA as a historic anomaly. Humans are town building animals.

But of course, I don't want greater efficiency to come with a loss of resiliency. Finding the balance between the two is difficult. I think my idea of hyper resilient rural systems feeding more intensive urban systems is on the right track.

Finally, maybe it is impossible to feed the urban masses. But that attitude is admitting defeat before the battle. The more work we do, the nearer we will get.

I guess the balance between efficiency and resiliency is just a really hard question. If I had a hundred acres, I would plant a diverse bunch of nut trees, run some cattle, and have a quarter acre garden of hardy perennial vegetables and landraces. On my 500 square feet for this experiment, I'm trying to see how efficient a more resilient system can be.

I just saw your second post. Good to know.