A couple of years ago I began growing multiplier onions for the first time. I had hopes of finding perennial onions that did well in my garden and in our climate. I’ve been growing garlic for quite a few years, and I like how you can save your own planting stock and replant it year after year. With multiplier onions, you plant a single bulb and as they grow they split (or multiply) into a clump of bulbs. So far I’ve planted two different kinds of onions, I’Itoi and Yellow Potato Onion. Both of them are heirloom varieties with a rich history, and both are enjoying somewhat of a revival in the 21st century. They did quite well for me here in the garden, and have proven to be very useful in the kitchen too. I will be planting them outside around the end of October, though I already have some of the I’itoi growing in containers.
Michelle (From Seed To Table) did a Variety Spotlight in 2016 on the I’itoi, which helped to inspire me to try growing them. I got my planting stock in the form of sets from Native Seeds/SEARCH. They are listed in the Slow Food USA’s Ark of Taste, and the listing there gives a bit of the history and mystery surrounding this tasty heirloom. Michelle gives quite a bit of the history in her post as well, and talks about her experiences growing them.
The I’itoi onions don’t get real big for me, but I find they are most useful as a green onion or scallion. I’ve grown them in ground and in containers, and they do well either way.The clumps do seem to get bigger when planted in the ground, but the container plantings usually give me scallions a bit earlier than the ones in ground. The bulbs resemble small shallots, and can be used like you would shallots or onions.
There isn’t a whole lot of information available on growing these onions, and at first I wasn’t sure if they would be hardy in our area or not. But they have survived our winters unscathed so far, and last year the temperature got down to -6°F one night. They tend to go dormant here in summer for a bit and dry out, and that is when I usually lift and divide them. If left in place they will start to sprout fairly quickly, and you can see in the below photo many in the clump are doing just that.When planting in containers I set them fairly close, usually 2 to 3 inches apart. When planting in ground I space them about 6 inches apart.
Potato onion is a common name for a type of multiplier onion that is similar to shallots and has good keeping qualities. The Yellow Potato Onion comes from a strain that dates back before 1790, when multiplier onions were widely planted in home gardens. It makes bulbs that can get up to 4 inches in diameter, though mine make bulbs mostly in the 1 to 2 inch range. I got these onion sets from Southern Exposure Seed Exchange, and their Garlic and Perennial Onion Growing Guide has information about planting and harvesting the potato onions.
The Yellow Potato Onion is widely adapted for growing in most of the U.S., and is tolerant of drought conditions too. Fall planted potato onions usually get bigger than those planted in spring. The green tops are also edible, though for me the real attraction is the bulbs. Their size is just right for seasoning a lot of dishes, and though hot when raw the flavor mellows with cooking.
The Yellow Potato Onions have also survived our winters when planted out in the open ground in late fall. I mulch with a layer of straw to protect the bulbs and to help keep down weeds. You can see them emerging in spring in the below photo, in front of the taller garlic plants. I’ve been spacing them like I do my garlic, in a grid 6 by 8 inches apart. I plant them deep enough so there’s about a half inch to an inch of soil over the top of the bulb.
I hope you have enjoyed this update about growing multiplier onions here in our garden. They have been an easy to grow addition to the garden lineup the last few years. I’ll be back soon with more from Happy Acres!