Garden

the making of an urban biointensive garden in Toronto

Friday, April 20, 2007

Life of a double-digger

I prepared my first raised bed yesterday by double-digging an existing 18-square-foot bed in the front yard. Double-digging is one of the essential features of the biointensive method. It originates in French intensive gardening, which was developed for people with narrow backyards in France to enable higher yields for a given area. The idea is to loosen the soil two feet deep without completely disturbing the natural soil profile, so that roots can easily delve deep rather than spread out.

HtGMV describes several different bed preparation procedures you can choose from, depending on whether you're double-digging it for the first time, preparing last year's biointensive bed, starting a bed in poor soil, and so on. I followed the "Initial Double-Dig" procedure, since even though I was preparing it from an existing garden bed, the bed hadn't previously been worked biointensively. Here's the simplified version:

  1. Loosen the top 12 inches of soil with a spading fork (I highly recommend the beautiful, stainless-steel Lee Valley tools) and remove any weeds, roots, or stones you came across.
  2. Spread a 1-inch layer of compost over the entire area.
  3. Using a flat-edge spade, remove the soil from the upper part of the first trench (a couple feet wide) and place it in a soil storage area for use in making compost and flat soil.
  4. Loosen the soil in the first trench an additional 12 inches using the spading fork.
  5. Dig out the upper part of the second trench and move it into the first trench. The first trench is complete.
  6. Loosen the lower part of the second trench.
  7. Lather, rinse, repeat, until you've reached the end of the bed.
  8. Shape the bed into a mound by raking it.

Result:

Ain't that somethin'?

Next, I planted carrots, radishes, sunflowers and edible flowers. Carrots and radishes both like to be planted next to lettuce. They are companion plants, which is another essential feature of biointensive gardening. Companion planting is a not-totally-understood phenomenon that some species of plants thrive better when grown next to certain other "companion" species. There are also some plant species that will inhibit the growth of certain other species ("antagonist" plants). The de-facto book on the subject is Carrots Love Tomatoes by Louise Riotte.

So back to the carrots, radishes and lettuce. Carrots and radishes like lettuce, so since I'll be expecting lettuce seedlings in a couple weeks, I left some room for lettuce to be planted nearby when the time comes. Carrots and radishes also make good companions themselves if they are interplanted amongst each other, as carrots take longer to mature than radishes, as this diagram illustrates:

I came up with a pretty ridiculous pattern for interplanting my radishes and carrots, based on the fact that carrots should be spaced about 3" apart and radishes 1" apart:

Please do not let this frighten you. Interplanting is completely optional. I just think it's super fun. (Remember, I was a math major.)

So then I poked holes where the seeds should go, popped the seeds in, covered the holes up, and gave the bed a healthy spray with the hose. I hope something grows out of it.

Labels: , , , , , ,