Iris tenax

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USDA Hardiness zone: Zn5b -10º to -15ºF

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Oregon iris or Tough leaved iris is the most northerly species of Pacifica Iris- extending its native zone as far as SW Washington. Its common throughout the western part of our state where it decorates grassy hillsides in full sun to quite a bit of shade with jolly purple flowers April-June. That was the most common color where I grew up SW of Eugene. Turns out this Iris comes in quite a few colors. Pink, blue, white, golden yellow, red- all hues that have been recorded for this species. Conspicuous also, among the 11 Pacifica species this is a winter deciduous perennial and its the hardiest of the lot. Forms grassy clumps in fan shaped displays to about 10″ tall.  A large clump can be 30″ across and filled with nearly 100 flowers- these rise on cantilevered stems to 14″ tall. Not very tolerant of disturbance and to be honest it has stymied us quite a few times. They HATE division. Therefore, we feature seed grown plants- local seed. These plants feature extra vigor and usually bloom with in 3 years. They also establish better.  Best in light shade, dappled shade on slopes. Average, clay soil is what it wants and you can increase vigor by double digging the hole very wide to incorporate oxygen in the soil and water lightly and consistently through the first summer. Then none to light in subsequent years. And admirable competitor with introduced invasives and as per all Iris it is supremely deer and even rabbit resistant.  Winter deciduous- also, it may go drought deciduous in extremely dry summers. Mixes well with native annuals. Established clumps live for decades. The flowers have the light fragrance of root beer (at least to me) and are the only fragrant Pacifica species that I can detect.  First nation people used the incredibly tough leaves to braid into ropes, traps. Which is cool.  Photo credit: East Multnomah Conservation District. Oregon native plant.

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