An important component of sustainable food production systems is small-scale gardening and permaculture. Since we moved into our house two years ago we have been experimenting with different crops and horticultural techniques in order to learn how to grow our own food in a sustainable manner. Our goal has been to figure out what crops grow well under the harsh conditions of an urban yard in Tucson. Most of our gardening attempts have met with failure, but these failures have taught us a lot and we’re slowly getting better at it. To a large degree we’ve set ourselves up for failure, as we’ve attempted to grow food using minimal water and minimal external inputs of fertilizer, mulch or manure.

Devil’s claw

A devil’s claw (Proboscidea parviflora) plant in our garden, one of the few summer crops we had success with this year. The fresh green pods can be cooked like okra, the seeds inside the dried and split pods can also be eaten, and fibers from the dried pods can be used in basketry. This was an important crop to the Tohono O’odham people of southern Arizona (among others).

A food production system is only truly “sustainable” if it can be utilized forever without repeated inputs of external non-renewable resources. In the case of a garden, I consider that to mean that only on-site resources should be used, with careful attention paid to recycling materials and completing nutrient cycles. At our site we are missing two critical items which would make our garden more-or-less sustainable (though not necessarily productive): a rainwater-harvesting cistern to provide water during dry parts of the year, and a composting toilet to recycle nutrients (rather than flushing them away). We plan to address both of these constraints eventually.

We are trying to achieve the following goals for our garden (we have a very long way to go before we achieve all of these goals, but we’re making gradual progress towards them):

  1. Avoiding external inputs of mulch, manure, fertilizer, or other soil amendments in favor of chicken manure, compost and mulch derived on-site (status: work in progress)
  2. Avoiding use of synthetic biocides (status: fully achieved)
  3. Avoiding use of municipal water by maximizing rainwater harvesting (using berms and sunken beds to channel runoff to the garden) and minimizing evaporation (by using mulch and shade) (status: work in progress)
  4. Minimizing tillage of the soil to reduce erosion and promote healthy soil microflora and microfauna (status: fully achieved)
  5. Intercropping with a high diversity of plants to reduce disease transmission and pest infestations (status: work in progress)
  6. Emphasizing native crop species adapted to our local conditions (status: work in progress)
  7. Emphasizing perennial species (which have a number of advantages over annual crops) (status: work in progress)
  8. Encouraging edible native “weeds” (status: work in progress)

In the next post I will describe our new fall garden, which I finally got planted today (a couple weeks later than I had hoped!). I will use this new garden to illustrate some of the ways in which we’re trying to achieve our sustainable gardening goals.

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