Iris tenax

tough-leaf iris

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Outstanding Qualities

This reliable native West Coast iris is floriferous and resilient in the garden. In May these low mounding, evergreen perennials produce a profusion of blooms ranging from pale lavender, rich purple to pale violet-blue that show well against the evergreen foliage. Once established it will tolerate drought and gently reseed. This is the easiest to grow of the native iris and the hardiest. It is great for rockeries, along the edge of gravel paths or the front of the perennial border.

Quick Facts

Plant Type: clumping perennial

Foliage Type: evergreen

Plant Height: 1 ft. 0 in. (0.30 meters)

Plant Width/Spread: 2 ft. 0 in. (0.61 meters)

Hardiness: USDA Zones 7 to 9

Flower Color: blue, lavender, purple

Sun/Light Exposure: full sun to light shade

Water Requirements: occasional watering to drought tolerant once established

Seasonal Interest: peak bloom is in May

Wildlife Associations: bees, butterflies

Resistant to: aphids, rabbits, deer

Colors & Combos

Great Color Contrasts: orange, yellow

Great Color Partners: blue, pink, purple, silver

Culture Notes
Tough-leaf iris will grow best in full sun to light shade. This iris is not fussy about soil types, but does demand a well-drained location. Wet feet will kill this plant. This native iris resents root disturbance during its dormant season in summer. Plants can be divided or moved only in September or October once the new root have started to grow. It is best to move seedlings while they are still young. Dead leaves can be removed in late winter; little more needs to be done. If it needs further clean up, the remaining foliage can be trimmed in mid to late March, but care must be taken not to clip off the newly emerging leaves.