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Spokane, Washington  Est. May 19, 1883

Try loosening soil rather than a complete turn over

These Austrian field peas were planted last fall and will soon be chopped up and added to the soil to increase nitrogen levels. (Susan Mulvihill)

They say you can’t teach an old dog new tricks. But when it comes to gardening, this old dog is always ready to learn something new.

For years, I have been a proponent of turning over the soil in vegetable gardens because I’ve felt it helps plant roots push through the soil more easily. Now I’m hearing that process can destroy the structure of the soil.

In the spring 2011 issue of Mother Earth News’ Guide to Organic Gardening magazine, writer Harvey Ussery says: “There are almost always alternatives to tillage, especially power tillage, which inverts and mixes the different layers in the soil profile, disrupts the soil food web and breaks down the ‘crumb’ structure we have worked so hard to achieve.”

He advocates the use of a broadfork tool to loosen the soil, cover crops to feed the soil and some free-range chickens to scratch the mulch and other amendments into the first couple of inches of soil.

Chickens and a broadfork won’t work in my garden, but I’ll use cover crops and gently loosen the soil with a spading fork instead of turning it over.

One thing I do know is that nothing will destroy soil structure faster than working with it when it’s still too wet. If you grab a handful of soil and squeeze it, it shouldn’t be wet and muddy. If the ball of soil easily breaks apart when poked with a finger, it is ready.

Since soil is the very foundation of a productive garden, we should build it up annually. We can do this by adding organic materials like compost, shredded leaves or composted manure to the surface of the soil.

I grow my veggies in raised beds. Since I walk on the paths around the beds rather than on them, the soil stays loose, making it easy for plant roots to transport moisture and nutrients.

No matter what type of garden set-up you have, walking on the soil near the plants should be avoided.

Whether you have an established garden or are preparing a new site, it’s a good idea to do a simple soil test to find out the pH of the soil and get a feel for the levels of nutrients that are available.

Soil pH is a measure of the amount of acidity or alkalinity. Vegetables tend to grow best in soil with a pH that falls between 5.5 to 7.5. In our region, most soils fall within that range.

Soil test kits can be found at garden centers and online. In addition to rating the pH level, a soil test will show the amounts of nitrogen (for healthy leaf growth), phosphorus (for flowering, fruiting and root branching) and potassium (for regulating water movement and cold-hardiness).

A test kit will help you learn which amendments should be added to the soil.

Cover crops are plants that are grown on vacant garden beds, usually from late summer to early spring. They become “green manure” when they are chopped down before they start setting seed, thus replenishing the soil with nutrients and organic matter as they decompose.

The most commonly grown cover crops are clover, buckwheat, hairy vetch, winter rye and Austrian field peas.

Once our gardens are planted, the best thing we can do to help the soil retain its moisture is to cover the surface of each bed with mulch. Easily found mulching materials include shredded leaves, bark, grass clippings from an untreated lawn and weed-free straw.

Susan Mulvihill can be reached via e-mail at inthegarden@live.com.Visit her blog at susansinthe garden.blogspot.com for more garden tips and information.