Douglas iris (Iris douglasiana) is easily one of the most familiar and popular of West Coast native perennials. Its natural range extends from Southern California north as far as Washington, on coastal bluffs and prairies and in open woodlands in the Coast Ranges. While an occasional purple, white, or pale yellow flower can be found in wild populations, the typical color is pale blue or soft, lavender blue. Iris breeders have worked with this species, particularly in combination with several other native irises, in the development of the large, showy Pacific Coast Hybrid iris now common in gardens and nurseries during the spring flowering season. The simplicity of the wild forms of Douglas iris, however, still holds great appeal.
An outstanding selection of Douglas iris was made by Bay Area botanist Glenn Keator near the Pt Reyes lighthouse on the Northern California coast many years ago, before Pt Reyes became part of the National Park System. After observing how this clone flourished in his family’s garden in Alameda, he gave a division of it to native plant propagators at Strybing Arboretum and Botanical Gardens, part of a group of volunteers using the nursery facilities there to grow plants for Strybing Arboretum Society plant sales.
This selection has attractive, broad, dark green, glossy leaves that curve gracefully, making a low, evergreen ground cover. The flowers are a rich purple in color with delicate white markings on the falls. A touch of light yellow highlights the markings near the base of each petal. It blooms later than many of the native iris, usually beginning around early May. The flowers are beautiful individually and are produced in abundance.
Vigorous in growth and lovely in flower, this selection has been a favorite with customers at Strybing’s plant sales for many years. In the past, it has been sold as Iris douglasiana and given the designation Pt Reyes form. Since it clearly has proven to be a valuable clone, we have decided to give it the official cultivar name of ‘Pt Reyes’. It may be seen at Strybing in plantings on the Nature Trail between the pond and the paved walkway.
As with most native iris, ‘Pt Reyes’ is best planted in the autumn before the winter rains begin in earnest. In coastal areas, a site with full exposure to sun and wind is acceptable; in warmer, interior areas, planting is best in light or dappled shade. Douglas iris, ‘Pt Reyes’ included, makes a fine ground cover under native oaks and can be used to reduce erosion on gentle slopes.
Iris douglasiana ‘Pt Reyes’ will continue to be offered for sale at Strybing Arboretum Society plant sales that feature California natives.