In the Pacific Northwest, good sweet potato growing takes a lot of effort. Potatoes grow and over-winter to grow again. They are handy for growing through new mulch or piles of removed sod since they can draw notrogen from pretty far away from the upper greens.
For me, sweet potatoes have worked well because they cover ground quickly with edible leaves, produce lots of biomass above ground, and leaving the tubers in the ground makes large pockets of rotting OM right where you want it with no digging required. Potatoes don't produce nearly as much leaf growth (at least not in my climate) and if you left them in the ground they would just grow back with an increasing chance of fungal issues.
All of that is not to mention that sweet potato tubers are a lot more nutritious than potatoes. I would think even in the northwest if you can't actually get a tuber crop it would still make sense as a soil builder, especially since you can buy one or two at the store and produce 100 or so slips yourself.
Michigan zone 4 b...have a sweet potato in a pot that sprouted, the vines are about 5" long right now, 2 of them and then a smaller one..I've never grown sweet potatoes before as it is COLD here. We won't have warm enough weather to plant them outside for another 6 weeks here (we still get frost with the first full moon in June)..but I plan to plant them into my raised bed that people suggested I try to improve the soil there (kinda hugel but mostly clay)..will let you know what happens after that.
Bloom where you are planted.
Location: St. Pete,FL
posted 8 years ago
Look forward to hearing how you do. Since I am in central Florida, zone 9, warmth should not be a factor.
Location: Southern Appalachia
posted 8 years ago
Sand Hill Preservation Center sells Sweet potato slips. They have a lot of heirloom varieties and they sell a "northern assortment" for short season areas. He also gives a lot of quality cultural information.