Pinterest has been full of ways to grow this or that lately, and one of the ones that intrigued me most was how easy it was to grow your own green onions (also known as scallions). I thought surely, it wasn’t quite as easy as all the pinners said. Surely, there must be some trick, right?

Nope.

It really is very easy to grow scallions. Simply save the bottoms that you normally throw away (the onion bulb part with the roots) and pop them in a jar of water. Sit in a sunny window, and they will grow again. Fast. They grow really fast! Here’s mine on day one, and then again three days later:

In just three days, with water only, they’ve grown from under the jar’s rim to an inch above it. There’s nothing added to the water–it is simple tap water. From what I gather, you can do this four or five times, harvesting the scallions you need, before you need to start over with a new bunch of green onions.

Update: I’ve had my jar of green onions in my window for a month now. It has grown to full height three times–usually within 7-10 days each time. The first time I cut them and used them in a recipe. The second time I cut them and froze them in a plastic bottle, and now shake out whatever I need when I cook. They cook up just the same! They are just approaching the third full growth, and I will cut them and freeze them again. Based on appearances, I might get one more growth out of them. They look a little skinnier this time than last time.