Well, depending on what you're trying to grow....about 4-1/2 months. I can set things out around the second week of June, and generally start clean-up some time in October. There are a few things, like pansies, that are happy longer, but that's pretty much the time frame for most of the annuals. My clematis and peonies have broken ground already, tho, and the roses that survived (grrrrrr) have started sprouting. And the daylilies are going great guns. Gonna have to get more of those puppies, 'cause it looks like they'll do ok in raised beds. Sigh, you can't even walk around yet in most of the garden without sinking in and getting your feet wet. I have one tray of pansies that I'm thinking about kicking outdoors.