im going to do mine in about 2weeks you can start planting now if the weather is a bit warmer where you are.books say end of march/april time for first early varieties,but we have had a bad winter so ground needs to warm up a bit first.

Last three days of March is the first time if you are growing by the moon, then not until 7 - 9 April. Of course if you aren't planting by the moon any time after 29 March.