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How to Grow I’itoi Onions

In 2015 when I took the Master Gardener classes, they gave each student a couple of withered, sad-looking I’itoi onion bulbs. I was disappointed and thought, “There’s no way these will grow.

I was wrong. That couple of I’itoi onions has multiplied into thousands of bulbs that have since been eaten, planted, and shared with many others. 

I’itoi onions tolerate and thrive in the Sonoran Desert’s difficult growing conditions. I’itoi onions (pronounced “EE-EE-toy”) have a long history in the Sonoran Desert. According to legend, I’itoi – the creator of the O’odham people – called his people together and presented them with onions to plant and share. Learn how to grow I’itoi onions with these tips.


9 Tips for How to Grow I’itoi Onions

Learn how to grow I'itoi onions, and you will soon have enough to enjoy, plant again, and share with your friends and neighbors.

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1. Find bulbs to plant I’itoi onions

Some years, it is hard to know where to buy I’itoi onions. They can be challenging to come by. In other years, it’s easy to find them at the farmer’s market or other local sellers. Check Native Seeds Search or Crooked Sky Farm, as they may have them available for purchase.

How to Grow I'itoi Onions

If you’re having difficulty finding I’itoi onion bulbs to plant, ask other gardeners – they may have some to share.

Beginning in July at Arizona Worm Farm, you can buy some of this year’s I’itoi onion harvest to plant next season. All proceeds will benefit St. Vincent de Paul and Project Roots.

Learn how to grow I'itoi onions, and you will soon have enough to enjoy, plant again, and share with your friends and neighbors.

2. Understand how I’itoi onions grow

I’itoi onions are a multiplier onion (allium cepa var. Aggregatum). The planted onion multiplies and is propagated by the division of bulbs.

Learn how to grow I'itoi onions, and you will soon have enough to enjoy, plant again, and share with your friends and neighbors.

From just a single bulb, the magic of nature unfolds. Plant it once, and it multiplies into 8 or 10 (or even more) bulbs. Once harvested, each of those bulbs can be divided and planted, resulting in another extraordinary multiplication. Behold the astonishment as 1-2 onions, within a span of only a couple of seasons, transform into a bountiful harvest of hundreds.


3. Plant and care for I’itoi onions correctly

How to Grow I'itoi Onions

When to plant I’itoi onions

In cold winter areas, plant I’itoi onions in the spring. 

In the low desert of Arizona, I’itoi onions are normally planted with the monsoon moisture in August; continue planting through NovemberHowever, this tough, easy-to-grow onion can probably be planted successfully most times of the year.

Learn how to grow I'itoi onions, and you will soon have enough to enjoy, plant again, and share with your friends and neighbors.

How to plant I’itoi onions

I keep the clump of bulbs together until I’m ready to plant, just like garlic. Once I’m prepared to plant, I carefully separate each bulb and plant them individually.

To ensure optimal growth, plant each bulb approximately 1 inch (2.54 cm) deep, spacing them 6-8 inches (15-20 cm) apart. For square-foot gardening, place four bulbs within each square.

How to Grow I'itoi Onions

Where to plant I’itoi onions

I’itoi onions will grow in native soil, requiring no additional feeding. Nevertheless, richer soil yields a more abundant harvest of larger bulbs and shoots. I grow my I’itoi onions in raised beds with the Raised Bed Mix from Arizona Worm Farm. The rich soil produces large bulbs and plentiful greens.

I’itoi onions grow well in containers and can be tucked in almost anywhere in your garden.

How to Grow I'itoi Onions

Choose an area with plenty of sunlight if possible. They tolerate shady conditions, but the bulbs will be smaller. I’itoi onions can be grown in full sun. They normally die back and are dormant if left in the ground during the hottest parts of summer.

How to Grow I'itoi Onions

How to care for I’itoi onions

I’itoi onions tolerate dry conditions and will respond to monsoons and other rains with growth. Just as with amendments to the soil, regular watering produces larger bulbs and shoots.

Once these onions are planted, they thrive effortlessly and require minimal care. Pest and disease problems are uncommon, allowing for a worry-free growing experience.

Occasionally, I’itoi onions will bolt and flower. The bolted onions will not store as well and should be used right away. While I’itoi onions are typically cultivated from bulbs, if seeds are allowed to develop on the flowers, they can be used for planting. My experience with growing I’itoi onions from seeds has yielded varying degrees of success.

Occasionally I'itoi onions will bolt and flower. The bolted onions will not store as well and should be used right away. While I'itoi onions are typically cultivated from bulbs, if seeds are allowed to develop on the flowers, they can be used for planting. My experience with growing I'itoi onions from seeds has yielded varying degrees of success.

4. Plant I’itoi onions as companion plants

Because I’itoi onions are easy to grow, it is simple to plant them throughout the garden. Onions are excellent companion plants for brassicas, beets, strawberries, and tomatoes

I'itoi onions planted as companion plants with strawberries
I’itoi onions planted as companion plants with strawberries

By planting a single bulb in close proximity to the plant, the I’itoi onions will flourish, multiply, and offer valuable companion planting advantages. For more information on preventing pests organically, read this post.

Plant I’itoi onions as companion plants. I'itoi onions planted as companion plants with cabbage.
I’itoi onions planted as companion plants with cabbage

5. Use all parts of the I’itoi onion as needed throughout the season

As green shoots develop, harvest as needed by trimming them off the onion. The greens have a mild flavor and work well in most recipes that call for chives or green onions. The onion will regrow new shoots.

Use all parts of the I’itoi onion - How to Grow I'itoi Onions

Harvest individual bulbs as needed throughout the growing season. To harvest individual bulbs off of the clump, carefully dig down until you see the base of the onion. Pull off as many onions as needed, and then push the soil back around the remaining onions.

To use the bulb, wash and peel. The bulbs have a mild, peppery flavor similar to shallots. They are delicious sautéed and in recipes that call for shallots or onions.

Use all parts of the I’itoi onion - How to Grow I'itoi Onions

6. Harvest I’itoi onions at the right time

How to Grow I'itoi Onions

The best time to harvest I’itoi onions depends on what you are using them for.

For fresh eating, harvest the greens or bulbs anytime throughout the growing season.

The best time to harvest I'itoi onions depends on what you are using them for.

For the largest bulbs, allow the greens to die back and then harvest. The bulbs develop a papery skin. In the low desert of Arizona, I’itoi onions are usually ready for harvest between May and July.

Onions that are harvested when the stalks are still green can still be cured, but it takes longer, and the bulbs will be smaller.

when to harvest I'itoi Onions

If desired, you can leave the bulbs in the ground after the greens die back. They will go somewhat dormant over the summer and then begin growing again in early fall.

The best time to harvest I'itoi onions depends on what you are using them for.

Pull up clumps of onions and allow them to cure for the most extended storage life. Onions may rot and mold if not cured and stored correctly. 

when to harvest I'itoi Onions - How to Grow I'itoi Onions

Although you can leave them in the ground, I prefer to harvest, cure, divide, and replant the onions with the monsoon moisture. The onions will multiply much more if harvested and replanted separately rather than staying in one large clump.

I’itoi onions re-sprouting after the tops die back.

7. Cure I’itoi onions before storing

Cure until the onion stems wither and the papery skins tighten around the onions. The dried stems will slip easily from the onion when they are done curing.

How to cure I’itoi onions: 

  • Choose a shady location around 75-80°F (24-27°C). Provide a slight breeze with a fan if possible if it is indoors.
  • Lay the onions out on a rack or floor.
  • Cure until the onion stems wither and the papery skins tighten around the onions. The dried stems will slip easily from the onion when they are done curing.
Cure until the onion stems wither and the papery skins tighten around the onions. The dried stems will slip easily from the onion when they are done curing.

I cure my I’itoi onions in racks inside this repurposed dresser-turned-potting table.

How to Grow I'itoi Onions
Cure I'itoi onions before storing
Cure I'itoi onions before storing

8. Store cured I’itoi onions correctly

Store cured I'itoi Onions Correctly

Store cured I’itoi onions in a dry, cool place. A great way to store onions is in mesh net bags (I use these mesh bags from Amazon) hung up in a cool closet. The onions must have good airflow, or they will get moldy. 

Check stored onions regularly, and discard (or plant right away) soft or moldy onions.


9. Enjoy, save, and share I’itoi onions

Whenever you harvest I’itoi onions, make sure to enjoy a portion, set aside some for planting, and generously share the rest with fellow onion enthusiasts. Let the goodness grow and spread!

Learn how to grow I'itoi onions, and you will soon have enough to enjoy, plant again, and share with your friends and neighbors.


If this post about how to grow I’itoi onions was helpful, please share it:


Mary Beth Harrer

Friday 19th of April 2024

I just attempted my first harvest and curing of these onions. Is it ok that the weather was a little over 80 (almost 90 here in Phoenix)?

Mary Beth Harrer

Saturday 4th of May 2024

@Angela Judd, I’m sorry, I should clarify; I cured them last month where the daily temperature was over 80. They look cured though! I was just wondering if there were any issues with curing them in the higher temperature. Thank you!

Angela Judd

Saturday 20th of April 2024

Yes, they tolerate it pretty well.

SE_Gardener

Sunday 28th of January 2024

Hi Angela, thanks for sharing all the gardening info/wisdom. I find it valuable to hear how gardeners plant and grow in different parts of the country. I live TN Cumerland Plateau with Great Valley of middle and west TN paralleling to our west and the Great Smoky Mountains on our east. Like your weather, all have their own challenges. Our weather is Zone7 is schizophrenic here at 2000ft elevation. Our summers are described as subtropical with warm humid weather and winters typical mountain freeze. Coming form the Midwest I had to learn how to garden all over again. My first 3 yrs were abysmal failures and in spite of all my garden knowlege and skills, I was stumped. The insect pressure and fungus/mildew can be venerable opponents! I've finally resorted to growing under protective cover of polytunnels and a year round grnhse for 80% of my growing in grow bags, hydroponic slabs, raised inground beds and multiple Greenstalks with only two long 18ft raised beds uncovered for bush beans, corn etc. This handles the insect pressure, heavy rain downfalls and storm winds assuring harvests. I'Itoi onions in my area seem to survive our winters left in ground. Note however, we do not have frequent subfreezing weather or teens for long periods of time in spite of temps occasionally will dip down to teens and 0°F. Daytime sun will warm a little. Our freeze-thaw cycles are generally not extreme - weather is generally temperate with lots of short up/downs - last week temps were near zero overnight for two nights and five days later temps were low 60's. It seems I'itoi will overwinter here Z7 in raised beds inside unheated polytunnel or microclimates. They tend to go dormant here in heat of summer for a bit and dry out - good time to lift and divide. If left in place they will start to sprout fairly quickly in cooler fall temps and continue to grow until dead of winter Jan-Feb. I can't speak to how well they would survive overwintering out in an unprotected areas.

Angela Judd

Monday 29th of January 2024

Thank you for sharing this. I can't speak from experience for colder conditions, so your observations are helpful!

Rebecca

Friday 12th of May 2023

Grew them this last year - loved it! Used your tips but I have one question.. when trimming the i'itoi onions to use how far down should I cut them to keep them growing and producing? There is a natural 'Y' in the stem growth it seems - should I trim below that or above? Or right down to the ground?

MNelson

Friday 15th of September 2023

@Rebecca, I assume by trim that you're referring to harvesting the green tops while leaving the remainder of the onion in the ground to continue growing; what my elders always called "cut and come again" plantings. I recently acquired some I'itoi sets from a seller on Etsy and this is my first attempt at growing these specifically, however, I have grown others and in my experience you can cut them quite short. I typically cut the tops down to within 1/2" -1" above the ground for immediate use when I need scallions/green onions and they remainder left behind have never failed to resprout and grow new green tops. I hope this answers your question.

DanBob

Tuesday 14th of March 2023

I have been growing I'itoi for about 8 years here in central AZ. They are the best as a scallion, or shallot, or even chives. We have 4 seasons here .................. 20's in the winter and 110's in the summer. The I'toi tolerate the extremes quite well. I grow them year round and replant anytime, as long as the soil isn't frozen. Now here's a tip ............ when you cut the roots off when prepping for dinner, save the roots and replant. Seriously, they will grow into a bunch of 30-40 scallions. Oh! Check out potato onions. :-)

Angela Judd

Wednesday 15th of March 2023

Great tips from a longtime grower. Thank you!!!

Cindy

Saturday 11th of February 2023

Where can we purchase these onions?

Theo

Monday 3rd of July 2023

@Cindy, the Chandler Nature Center should start to have some in their free seed cabinet sometime in mid to late August. You can always give the front desk a call to see if there are any in stock (the phone number comes up correctly when you google our name). We had a box of them generously donated to us a few years ago and love to give back to the community when we have extra! And we probably had close to 800ish onions this year. :)

Angela Judd

Tuesday 21st of February 2023

Check online at Native Seeds or Crooked Sky Farms they often carry them seasonally.