I tested early seeding by planting seed (Scotts Perennial Ryegrass) on April 3, 2013 when it was still cold. It was planted outside in a shallow pan in about 2 inches of potting soil. Seed was sown on top of loose, bare soil with no soil preparation or raking-in. It has now (May 2nd)(29 days), germinated and sprouted, and the tallest sprouts are about 20 mm tall, (about 1 inch). Here are today's soil temps, 65 to 70, but they might not be the same in a shallow pan. http://www.greencastonline.com/tools/SoilTempMaps.aspx Growing Degree Days base 50 (GDD 50) had reached 81 for the season.http://www.gddtracker.net/ Clearly, April 3 is not too early, but it appears germination was inhibited by the cold in the first two weeks, (there were 6 frosts). Soil was flooded by heavy rains about two weeks into the test; the pan was tilted for a few hours until the excess water drained out and then poured off. The soil then cracked as it dried out.