CORVALLIS - The balmy early days of spring tempt gardeners to poke around in their cold, sodden soil. But don't get too zealous with the rototiller without checking the water content of your soil.
"Rototilling in wet soil can really ruin soil structure," warned John Hart, soil scientist with the Oregon State University Extension Service. "People have a propensity to over-rototill. It eliminates the air spaces necessary for root growth." Soil rototilled too early also will dry into hard clods, making preparation of a nice seed bed difficult. Water will not soak in as well into hard soil, and summer watering may be less effective, he said.
"If your soil contains even moderate amounts of clay, tilling with the right moisture content is critical," said Hart. "To determine whether the moisture content of clayey soil is satisfactory for tilling, take a handful of soil and squeeze it into a ball in your hand. The moisture content is good for tilling if slight pressure from your fingertips causes the ball to crumble."
Or, drop a ball of soil from waist height. If the ball shatters, it may be dry enough to be safe to work without destroying the structure.
If you want to work some compost into your soil early in the season, Hart recommended using nothing more powerful than a shovel or spading fork.
"Between winter storms or during a dry, warm spell might be a good time to work into your soil some of the compost you have sitting around," said Hart. "If the compost has been sitting on top of your garden as a mulch, it has been insulating the soil. As spring comes, this will prevent the soil from warming up. Mix the compost into the soil and you will speed the warming process, making earlier planting possible."