Douglas Iris, Iris douglasiana

By Dan Songster, Golden West College Native Garden – 2010 April

Type: Evergreen perennial
Light: Sun to partial shade
Soil: Well drained preferred, but adaptable
Water: Infrequent

Native from Santa Barbara to Oregon, this Iris has narrow, dark-green leaves, one and half to two feet long. Flower stalks push slightly above foliage with the light purple, lilac, or even light blue to cream colored flowers.

In the GWC Native Garden you can currently see most of our Douglas Iris in the Mixed Evergreen Forest community (North-east side of Garden). Sometimes you will see them spotted singly in other areas providing a point of interest near a boulder or log. Although it’s lovely spring flowers are enough to recommend this plant it is also widely used because of its tolerance of varying conditions. It can take sun or partial shade, drought or occasional water, and soils ranging from light to fairly heavy.

You often see it used in woodland settings and as part of Oak understory plantings, as focal points in almost any style of landscape near patios or walkway intersections where its lovely foliage can be appreciated year round (and of course it’s springtime flowers), and along with native grasses and bulbs, as a part of a meadow landscape. It can be successfully combined with all of the plants listed for the Pink Flowering Currant (Plant of the Month, February, 2010) including Meadow Rue, Coffeeberry, Columbine, and Coral Bells. What a versatile garden performer.

Although drought tolerant it may like light watering in spring to extend blooming. Unlike some natives it can tolerate some summer water-but don’t overdo the water in heavy soils. It appreciates some light shade or dappled light unless planted very near the coast where it enjoys full sun.  Maintenance? Well, not much is required other than keeping the weeds (especially the grassy weeds like Veldt grass) out of it. Some people pick off the dead blooms but we leave ours on and allow them to go to seed and we then pot up the sprouting seedlings for our plant sales or for use in other parts of the Garden. It is fairly normal for the tips of the Iris foliage to discolor with age and they can be pruned (not pulled) off if objectionable.

Hybrids: Over the years many have been chosen and named but are often lumped under the label, Pacific Coast Hybrids (PCH). These hybrids are bred for larger more colorful and showy flowers but the plants themselves are often weak and don’t last long in the garden unless you have light loamy soils. We still use them occasionally for the short show of color and for our own desire to see what unexpected colors will emerge during the spring bloom. An exceptional hybrid both in garden durability (several years in the garden unless consistently overwatered) and in flower color is one Iris named ‘Canyon Snow’.  It has pure white petals with butterscotch yellow veins in them. Beautiful whether close up or from a distance.