This crop starts with a jar of water and toothpicks

This Garnet sweet potato has plenty of leafy sprouts and pink roots. (Photos: Debbie Arrington)

Get going on your summer garden without getting your hands dirty. All these sprouts need is water, not soil.

It’s easy to grow your own sweet potatoes. In fact, you can start this favorite vegetable on your windowsill right now – without any seed.

Home gardeners can grow new sweet potato plants by sprouting a sweet potato tuber in water. All you need is a jar (with a mouth large enough to accommodate a sweet potato), toothpicks and a mature sweet potato.

The method is super simple: Stick the sweet potato in the jar. Position the sweet potato so that half of it will be below the jar’s rim (but not touching the jar’s bottom) and the other half above. Use three or four toothpicks stuck into the sweet potato to suspend it in that position. Fill the jar with water and place it in a sunny warm spot (such as a kitchen window). Then, wait. The sweet potato will start sprouting roots and leaves within two weeks.

It’s those leafy sprouts on top – called “slips” – that will become new plants. Let them grow out until they are at least 4 to 6 inches long. Each sweet potato will produce at least a half dozen slips.

When the slips are long enough, gently remove them from their mother sweet potato and root their stems in water, letting their leaves hang over the rim of a jar or dish. In mid-spring, those rooted slips will be transplanted into the garden or large pots outdoors.

In addition to giving you a head start on your summer garden, pretty sweet potato plants brighten your winter windowsill – and fascinate kids (and gardeners) of all ages.

In general, supermarket-bought sweet potatoes will work. The most popular varieties (all high yield) are Beauregard, Jewel and Garnet; they’re mild in flavor with yellow or orange flesh. Purple-fleshed Japanese sweet potatoes as well as white-fleshed sweet potatoes such as Hannah also can be started with this method.

First, remember sweet potatoes aren’t really potatoes; they’re members of the morning glory family. They even have trumpet-shaped flowers that look like lavender morning glories.

They’re also not “red yams.” That name was a century-old marketing gimmick to differentiate orange-fleshed varieties from the more common (at that time) white sweet potatoes.