Growing Onions Over Winter (in NYC)

Tips on how to grow onions for overwintering for a Spring harvest. Includes planting dates and tips to protect them from frost in the Winter.

Growing Onions Over Winter

We usually plant our onions in March for a Fall harvest, but last year we decided we were also going to grow onions over Winter. For Winter you can grow onions from onion sets, or onion seeds. This post will focus on onion seeds but if you’re looking for sets, check out my full post on how to plant onion sets overwinter!

The result? Delicious sweet onions that are being used in our favorite slow cooker recipes and casserole recipes, as well as caramelized onions on top of everything and onion powder to last all year! 🙂

When should I start overwintering onions?

The seeds were started indoors during August and then transplanted outside into the ground in October (October 11 to be exact). You want to make sure the onions have a few weeks to get their roots established before cold and frost sets in. This gives ample time for them to settle in to their new home before first frost hits.

Although we prefer Candy onions (variety) for Spring and Summer planting, for Winter gardening we prefer Bridger (variety) onions.

How to Protect Onions Over Winter

After planting the onions, cover them with leaves to give them an extra layer of warmth to protect them from the cold. We are located in New York City so it gets fairly cold during Winter. You could even use garden fabric if it’s going to be especially cold.

Besides keeping them covered, you really don’t have to do much more than that, but just give them a little wave, and be excited for what’s to come soon!

I also want to note that we had a large amount of snow this past Winter, and these grew under the snow without any problem. I don’t have a photo of snow on top of the onions, but here’s a snowman we made in the garden to get a idea of snow fall. 🙂

Time to Pick the Onions

And almost 9 months later, the onions are ready to pick and gobble up! Onions are ready to be picked when their green tops fall over, but before they turn brown.

You’ll notice that these onions are pretty big in size, bigger than our usual Spring onions. The reason for the size is they have a much longer growing time.

Depending on the amount of onions you planted, you might have quite a few to store for the months to come. Here’s our favorite method for storing onions as it doesn’t take up too much space (we’re all about using vertical space!).

Now, go pull up your onions, give them a shake and enjoy!

PS: Like our garden signs? 🙂

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