Dirt Soufflé

One of the nicest things you can do for the vegetables in your garden is make them a dirt soufflé by double digging, as outlined in John Jeavons’ indispensable How to Grow More Vegetables and Fruits (and Fruits, Nuts, Berries, Grains, and Other Crops) Than You Ever Thought Possible on Less Land Than You Can Imagine. Basically, you dig a trench across one end of the bed about the depth of your garden spade and remove the soil for use in building your compost pile. (At this point, since I’m not fully Biointensive yet, I sprinkle in a little Sustane organic fertilizer and some rock phosphate—yes, I know the latter is not a sustainable practice, and I hope to get to phosphate self-sufficiency someday.)

Raised garden bed created by double-digging

A Dirt Soufflé

Then you loosen the soil at the bottom of the trench to the depth of your garden fork. Now cut out another trench next to this, and move the soil into the first trench, trying to disturb the soil block as little as possible. (This will be easier if the soil was well watered the day before.) Loosen the soil thus exposed, and repeat until you reach the other end of the bed. Now rake the soil towards the last trench starting from the other end until the bed is even. Spread a two-inch layer of compost over the bed and fork it in. (I usually add some humic acid and worm castings at this point.) Water well and let rest for 24 hours before planting, using a large piece of plywood that spans the bed to kneel on to avoid compacting the soil. Never step in the bed!

Voilà: a dirt soufflé! Your vegetables will be exploding with delight, as they need spend very little energy pushing down roots into the airy depths of the bed. One of the big benefits of double-digging is that it doesn’t disrupt the mycelial networks that plants depend on for nutrient uptake as much as tilling does. Soil is a living thing, and tilling wounds it severely.

Above is a 4’ by 10’ bed I finished today: you can see that even after taking out about 4 cubic feet of soil from the first trench, the bed is still about 4 inches higher than the compacted soil around it because the soil is so fluffy. This bed took me about two hours total, but I’ll speed up as I get back into shape. Bonus: it’s great exercise that works all the major muscle groups!

Double-digging looks quite labor intensive, but because you can plant vegetables in much denser arrays, it actually consumes less time per calorie harvested. Last year we harvested somewhere between 12 and 15 dozen carrots from a 4’ by 4’ double dug bed! After the initial double-digging, you can make do with a U-bar digger for several years before double digging again.

But don’t stint on your garden spade and fork, because they’re the foundation of double-digging and you will want tough, ergonomic ones. In the photo, you can see my Fiskars Big Step Garden Spade and Garden Fork. These are longer (47”) than the standard kind, and if you’re taller than 5’6” or so, you’ll appreciate the extra length, which means you don’t have to bend so much when using them. They’re all steel with a replaceable heavy-duty plastic handle, and a nice big corrugated step where your foot goes when pushing them into the soil.

If you’ve never done it, I encourage you to give double-digging a try, even if only in one bed. I guarantee, you won’t go back to standard gardening as long as your back holds out—and the exercise will probably help make your back stronger and less likely to betray you! And your food bill will go down, that I can guarantee.

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