Last winter we had a bag of "Maine potatoes" that "went bad" before we could finish it. There were about 7 full-size potatoes sprouting from multiple eyes. I kept them in a paper bag in the basement until spring. Then I cut these into about 32 chunks, each about 2"(5 cm) in diameter. I set these in a tray covered with paper bags in a cabinet under my basement sink for a couple weeks to scab over. In the early spring I sowed these chunks into a 12' x 3' (3.6 m x 0.9 m) bed. Over the following weeks plants started to emerge. I have been tucking straw around the bases and in-between these plants as they grow.
Just a warning -- The only problem I see with this is that you could be introducing diseases into your garden that you didn't have before. I've actually had this happen to me.
I only used either certified seed stock or my own homegrown potatoes for starting on my farm. But a few years ago the farm hosted our area's community garden. One of the volunteer gardeners brought store brought potatoes from home and planted them into the garden, without my knowledge. Regretfully those potatoes introduced early blight, a problem that didn't exist in my area before. As a result, growing potatoes in my main garden is now difficult. I have had to resort to using raised containers filled with virgin soil for growing potatoes and tomatoes.
It's never too late to start! I retired to homestead on the slopes of Mauna Loa, an active volcano. I relate snippets of my endeavor on my blog : www.kaufarmer.blogspot.com
Today I observed that Colorado potato beetles have arrived to investigate.
Location: Richwood, West Virginia
posted 5 months ago
Following directions I planted the 'Earlies' when the dandelions bloomed, about two weeks before the last expected frost, in 5 inch depressions and then mounded them as they grew. I had a bright idea and formed the sides of a raised bed with pieces of firewood to hold more fill around the potatoes, and then...I cut the bottoms out of 5 gallon buckets and upended them over the plants adding another 12 inches of soil around them. I figured I have at least 24 inches of soil bermed up around them now.