Heidi’s May Plant Pick: Blue Flag Iris

My May plant pick was found growing along the side of the road.  I don’t remember the details, but someone dug it up years ago and shared it with us.

I have come to love this wild iris.  Most likely it’s either a western blue flag, also known as the Rocky Mountain iris  (Iris Missouriensis) or a northern blue flag (Iris Versicolor).

wesrern blue flag

A Three-Season Iris

This beardless iris has beautiful blossoms.  The intricate pattern reminds me of butterfly wings.

Blue flag iris

The spring-blooming blossoms, which are usually two to three per stem, can range in color from light blue to purple.

Blue flag iris

They fade into green seed pods by summer.  The pods later curl open and dry to an attractive golden brown.

The dry seed pods look good for months and add winter interest to the garden.  They can also be used to add rustic structure to floral arrangements.

An American Classic

The western blue flag, a herbaceous perennial, is native to western North America.  Lewis and Clark noted this plant during their expedition.  Native Americans used it for medicinal purposes and to make rope.

The western blue flag and the northern blue flag are among several species of blue flag irises native to various regions of the United States.  The territories of these iris species often overlap, and their characteristics are very similar, which is why it is difficult to pinpoint the exact species of my iris.


This plant is often seen in wetland areas, but can do well in perennial beds in USDA zones 3 to 8 with consistently moist soil.  In my garden, it is watered only as often as the other perennials, and it does very well.

It thrives in full sun exposure, but it can also work in part shade.

Although it puts out seeds, I have never noticed any seedlings in my garden.  This plant has always stayed in one neat clump which has slowly expanded over the years.  It has dense, shallow roots which I separate when I want to divide it.

In my garden, this low-maintenance beauty benefits from occasional mulching but otherwise doesn’t need any special care and doesn’t seem to have many pests.

I consider the seed pods ornamental and leave them on the plant through winter.  Then in late winter or early spring, before new growth emerges, I trim away the old leaves and the seed pods.


Although this native perennial is considered endangered or threatened in some areas, in other areas it is considered an invasive.

It should not be used for naturalizing or in pastures as parts of this plant not only taste bitter to livestock but are poisonous.  And handling any part of this plant without gloves could lead to a skin rash.

Which all does sound a little scary.  But this wild iris has been a pleasure in my little garden.


Digging one up from the side of the road can be a big no-no.  Retailers stock seeds or root starts for this plant, including these seed retailers on Amazon.

Just make sure you are clear on the blossom color and height when you purchase.

And did you know:

That the French decorative design called the fleur-de-lis was inspired by the iris blossom?  From vintage items to accent pillows to wall stencils, the classic fleur-de-lis can be found all over Etsy.

pillow Large stencil linen Wall stencil vintage tray Large wall deal

Affiliate links used.

You might also enjoy:

Linking up with: