Sweet potatoes are grown from starts from a sweet potato, but most varieties in the grocery store need a longer growing season. Plus if they have been chilled at all (<10
oC) they don't sprout well. I am getting Georgia Jet which is relatively short season, and of course being well-rooted slips they should grow well. I won't plant them outside until the temperatures and soil are consistently warm, which means early June. I'll let you know how it goes come fall. If all goes well I will save a few potatoes (at >10
oC) and start my own next spring.
I have thought of a greenhouse, but the way the house is built it would be really awkward to add to the house. I could easily add to the (stand-alone) garage, but no water supply. The garage is far enough away from the house that piping water in would be difficult (and I would worry about pipes freezing) and carrying water in -20
oC weather is not appealing. What did you do for water? Horsepoor, what did you do?
Instead, I have a large shelf stand (the metal baker's rack type) and three shop lights, and put high-output fluorescents in them (on a timer). I can get lots of things started under them, and since they are in the laundry room I have a good water supply and don't care if I drip a bit on the tile floor.
I'm on the road to doing this! Built a greenhouse a few years ago to extend the Canadian growing season. Managed to produce wayyyyyyy too many chili and habanero peppers. Sweet potatoes would be a great idea! I'm testing out the branching out to fruit trees this year. Planted a raspberry bush last spring. :)