What to Know about Aase's Onions, Idaho's Native Onion

Posted on October 13, 2022 | Updated on September 30, 2025

Blake Hunter

This small onion is characterized by its pink blossoms, and long, drooping stalks. (Robert Moseley / Idaho Native Plant Society)

I had no idea that there are over 20 species of onion native to Idaho. But one in particular stands out: Aase’s Onion, or Allium aaseae.

When spring rolls around, keep your eye out for these little pink flowers close to the ground — they could be Aase’s Onion. They’re tucked along your trail route in any of the major Boise foothill reserves.

But look hard — because you won’t find them anywhere else.

Aase’s Onion, sometimes referred to as the Southern Idaho Onion, is endemic to this area, meaning they only live here, and nowhere else in the world. They can be found around the foothills around Emmett, where there’s similar sandy soils to our foothills, but that’s it.

Because it has a limited area in which to grow and prefers sandy soils, Aase’s Onion is quite rare, and the Idaho Native Plant Society categorizes its threat level as very high, mostly due to development, livestock, sand mining, recreation, and invasive species.

So if you see this little allium growing in your backyard, leave it be — and be careful to avoid it on the trails.

Thank you Boise, we’ve loved the conversation we’ve been having with you for the past three years. City Cast Boise and Hey Boise have suspended operations. Our last newsletter and podcast episode was Oct. 24, 2025.

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