From a bed a little more than 80 square feet this past summer, we harvested 81 pounds of potatoes. But for the visiting voles (similar to a mole) that showed a decided preference for potatoes in the diet, we would have had more -- 10 pounds or 15 pounds more, perhaps; just conceivably we would have hit the 100-pound total.
Totals aren't the point, however; it's how they were grown that might interest readers.
I had done some terracing and needed to raise the level of this particular bed. I had no spare soil available, but did have an abundance of leaves gathered in from off the neighborhood streets. These would do the trick, enriching the bed as they decayed.
First, I dug the bed to a depth of 12 inches and threw in tightly packed whole leaves to a depth of 24 inches. Next, I added half the excavated soil and worked this into the leaves with a garden fork, using a back-and-forth corkscrew motion. After this was done, I trampled the mixture to compact it.
Finally, I covered this soil-leaf mixture with the balance of the excavated soil (about 6 inches).
I should add that I did not dig the full length of the bed at one time, but rather did the work in about 3-foot segments.
Over the winter the bed settled nicely and some decay of the leaves did indeed begin to take place. However, it seemed to me that the ratio of undecayed leaves to soil was too high for many crops -- but not for potatoes.
I had frequently grown potatoes directly in leaves, following an old New England tradition. So growing them in a soil- leaf mixture would be no problem at all.
Moreover, growing potatoes in leaves will only speed the decay of the leaves, presumably by excreting substances from the roots. In other words, they would hasten leaf decay so that the bed could be used by other, less vigorously rooted plants.
I also tried deep planting of the seed potatoes, a method recommended to me by the folks at Ecology Action in Palo Alto, Calif. Deep planting, they said, did not retard potato growth and obviated the need to bank up around the plants as they grew -- a practice that is common in conventional plantings.
So, come the spring I planted the seed potatoes 8 inches deep in holes 14 inches apart in rows also 14 inches apart. The plants had no difficulty growing up from that depth and I may well try 10-inch-deep planting in the coming season. They grew vigorously, feeding no doubt on the steadily decaying leaves.
I suspect, too, that the leaves soaked up moisture from the good spring rains that fell in our area, thereafter meeting the needs of the potatoes during a particularly dry summer.
Apart from the voles, the potato bed was free of pests. And, while the bulk of the potatoes now in storage are totally unmarked, there are some with a few vole teeth marks on them. My wife simply peels the potato a little thicker when she comes across one of these.
In this day and age, it is no use being aqueamish about a slight blemish that can readily be cut out. The important thing is, we haven't had to buy potatoes from the market since we lifted ours in mid-August.
And from the look of it, we won't have to buy more until about March next year.
One point worth noting: When I dug the potatoes in August, the bulk of the leaves had thoroughly decayed.
Some tightly packed bunches were still visible but they could easily be crumbled into powder simply by rubbing them in the palm of my hand. In other words, that bed now is ready to accept any crop.