Last week I seeded our cole crops. I also set up the sweet potatoes in jars to start growing slips. You may remember doing this in elementary school. Or maybe not - I don't believe our kids ever did this. But when I was a kid in kindergarten we grew lots of things in paper cups: beans, tomatoes, marigolds, and sweet potatoes in jars on a sunny window ledge.
It takes a good bit of time for the slips to start so you have to be patient. Especially if you start the slips from grocery store sweets because they've likely been treated to discourage sprouting. But sprout they will! Once you have a good sized slip started you clip it from the mother tater and put it in a jar of its own to develop roots. Each potato will develop multiple slips so keep snipping and rooting them until you have as many as you want. Once the slips have good roots and the weather's warmed enough, into the garden they'll go!