Past Garden Tips: March 1999 -- Soil Preparation & Planting in Your Garden.

Catching the Spring Sun

Iris in snow. This is spring??

Brrr! This spring is unusual in the Sierra foothills. Days and nights are cold, and for 2 weeks I have had snows cooling my gardening enthusiasm. However, signs of spring are everywhere with perennials beginning to grow and spring bulbs adding cheer to the garden with their faithful blooms.

The vegetable garden calls to me. In the Sacramento valley my daughter-in-law has been picking lettuce and arugula for weeks, and I am hungry for greens from my own garden. With my clay soil so cold and wet I just cannot yet dig in the turkey manure compost until we have at least a week with no rain or snow. And since clay soil is slow to warm in the spring, even when I have my soil in perfect tilth, the soil temperature may not be high enough to germinate seeds.

Soil solarization is the answer. Often used for weed control, solarization also works to warm the soil, hastening germination of vegetable seeds and growth of young seedlings planted when the plastic is removed.

Soil should be amended first with compost, colloidal or rock phosphate, and oyster shell (refer to March garden tip). Using a fork or shovel, thoroughly mix the amendments into the soil (for those of you who use a rototiller or tractor, be certain that you are not compacting the soil by working it when it is too wet!).

Cover the bed with clear 3 to 4 mil plastic, sealing the outer edges with soil. Use a high quality plastic so that it will not deteriorate. Just a week of warm spring sun penetrating through the plastic will warm the soil several degrees and may even kill a few weeds. Two to three weeks will germinate all the weeds and kill them, leaving a vegetable garden bed ready for planting. Yes, of course you can use soil solarization for the flower garden too!

Meanwhile start a few lettuce and bok choy seeds in flats outside in a warm sunny spot. The flat could even be covered with Tufbell (available through Peaceful Valley Farm Supply), a film that will protect the young seedlings from frost.

When the plastic is removed, the bed is ready to plant with seeds and seedlings of lettuce, boy choy, peas, spinach, and other greens. No amendments need to be added, and the soil does not need to be turned again. You have already done that in preparation for soil solarization! By the end of April my vegetable garden will look like it has been planted for weeks. Here's hoping yours does as well.