2009-02-26 / News

Gardening 101: Digging

The Island Garden
By Roger Marshall

Let's talk this week about digging. It's hard to do right because the ground is frozen but in a few weeks gardeners will want to dig their garden patch over and plant something. There are several ways to dig your garden and even more ways not to dig your garden.

The traditional way is to take a spade or fork and dig, dig, dig, carefully removing weeds and stones as you go. If you do this enough times, your garden will eventually become weed and stone free. (And your back will ache enough to put you off gardening forever!) Some English gardens have been dug this way since the 12th century and there's not a weed or stone to be seen. Unfortunately, few American gardens have been dug for more than a hundred years or so, so we still have a ways to go to get good soil.

Then there's double-digging. This method is for building back muscles that you never knew you had. You first dig a one spade deep trench across the end of your garden and put all the newly dug soil at the other end of your garden. Then you dig over the soil at the bottom of the trench one spade deep. Now you dig a second trench next to the first and put all the newly dug soil into the first trench. Then dig over the soil at the bottom of the trench one spade deep. Repeat until your back gives out or you reach the end of your garden. If you've never dug a garden before, double-digging is a good way to loosen soil up to two feet deep. But try not to dump subsoil on top of good topsoil.

In Britain, pundits often suggest that you dig your garden in fall to remove old plant growth (it can harbor bugs and weed seeds). This allows the winter frosts to break down the soil. However, it also allows winter rains to leach nutrients out of the soil.

For modern man, the invention of the rototiller changed the way we dig. We can now vibrate our way from one end of the garden to the other, chewing up weeds, stones, debris, lost tools, and anything else in the garden. Rake the soil over and we're done. Unfortunately, it doesn't quite work that way. Usually you walk behind your rototiller, which compacts the soil, then when you rake, you compact the soil some more, plus you leave all the bits of weed seeds and roots to grow again. Soil compaction is made even worse if you do your rototilling when the soil is slightly wet. Rototilling also only tills the top six to eight inches, leaving the compacted soil underneath barely penetrable by plant roots. The ideal soil is deep, light, contains lots of organic matter, some sand for drainage, and is not compacted. Compacting soil stops roots from spreading far and wide and stunts plant growth.

So how do you get perfect gardening soil quickly? First, by not walking on the garden to compact it and second by not digging it. I grow the lazy way that saves work and time. In fall, I pick up leaves with the mulching lawn mower. These shredded leaves are dumped on the garden along with grass clippings (untreated grass clippings only). The leaves become mulch that eventually rots down. This mulch also helps to retain moisture during summer droughts. However, mulch tends to absorb nitrogen as it rots so you need to add extra nitrogen in spring in the form of well-rotted manure - horse manure is best. I grow in 4-footwide beds and can reach into the bed from either side. This ensures that the soil is never walked on and the plants are free to roam across the entire bed if they want to. I don't have to dig the garden over in spring, except where the leaves have blown off, and I reuse organic material that might go to the dump.

The only problem is that you must plant seedlings through the mulch. If you want to plant seeds - for carrots or beets, let's say - you must rake off the mulch or dig over a bare patch.

If you prefer to dig your garden over in spring and have a hot tub to ease your aching back, you should plant winter rye in fall to help to retain nutrients in the soil over the winter and provide extra nutrients when the rye is dug in. Unfortunately, for gardeners, that is, we don't get a heavy snow cover on the garden from November until April so rains tend to leach nutrients and you need to add nutrients in spring if you do not plant a winter cover.

If you plan on digging your garden by hand this spring, I suggest you start training now. Go to Jamestown Fitness and sign up for back and stomach exercises so that you won't spend a weekend digging and a week bent over from back pain.

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