Most growers will wait until after all chances of frost are past, but if you do plant them and a freeze comes along after they have sprouted it will only damage the above ground growth not the roots underground. Ideally the ground temp should be 45 degrees before planting for best results.
Here in Texas most people try to plant them here on or near Feb.14th.I have planted as late April .They don't get as big but made ok.
thanks. I really would love to grow some "baby new potatos". I tried to grow some last year but the ground hardened so much and then the horses decided to trample the area ): lol