Seattle’s average last frost date is April 20, but with signs of the garden coming to life all around us it’s tempting to ignore that mid-spring date. With a little knowledge a gardener can predict frost and take measures to temporarily protect tender plants. If the sky is clear and the wind is blowing from the northwest, get ready to take action. One simple technique is covering a tender plant with an old sheet. For more frost prediction signs and protection tips go online to A Gardener’s Guide to Frost