I can't say that I've figured out a magic date to start plants in the house to be transferred later into the garden here in North Dakota but I'm thinking now might be a good time.
I've tried as early as the first day that the sun starts it's swing back towards longer days... that was a disaster.
You don't want to start to early or your plants just get tall and spindly, then fall over and die.
We are probably two months from the garden actually being ready for planting. Currently there is about two feet of snow on the ground and the frost is most likely down close to six feet below the surface. All of that adds up to planting indoors now and also some re-potting in about thirty days.
So why do it? With our short growing season it's nice to get a head start so we can enjoy what we plant longer whether it be flowers or produce. After a long winter it also brings me pleasure to see those sprouts break the surface and bring life into the new year.
If you really want to know the key to successfully starting your garden early I'd like to recommend you check with our locally owned Lowe's Garden Center.