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

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.