Perennial Pleasures

By: Carol Bornstein

Carol Bornstein is one of Southern California’s most highly respected native plant specialists and co-author with David Fross and Bart O’Brien…

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Lessingia filaginifolia ‘Smart Aster’. Author’s photographs

Lessingia filaginifolia ‘Smart Aster’. Author’s photographs

As landscape designer Nan Fairbrother wrote,

Flowers are the last and least important class of vegetation for design, even though millions of contented gardeners consider them the essential raison d’etre of the whole process. . . . Just as architects are concerned with the structure of buildings, so landscape designers are concerned with the structure of landscape. When considering the overall design, flowers are largely irrelevant, for we can no more make a good garden by starting with flowers than a house by starting with the ornaments on the shelves.1

Sound advice indeed, but sometimes our passion for plants gets the better of us. When it comes to creating a California native garden, the most popular flowery perennials include monkey-flowers, irises, California poppy, California fuchsia, coral bells, and that rambunctious gem, Matilija poppy. To further whet gardeners’ appetites—the design process notwithstanding—the Santa Barbara Botanic Garden (SBBG) offers up four new herbaceous cultivars this fall.

Iris ‘Canyon Bliss’

Iris ‘Canyon Bliss’

Two Spring Beauties

Pacific Coast Hybrid irises are coveted for their exquisitely colored and patterned blossoms. Countless cultivars have been developed by professional and amateur breeders, with new color combinations and ever more frilly forms appearing annually. One of the best remains Iris ‘Canyon Snow’, a beautiful milky white flower with yellow eye spots that was selected by Dara Emery of SBBG. Since its release in 1975, ‘Canyon Snow’ has been one of the benchmarks by which other PCH cultivars are measured, because of its disease resistance, vigorous growth, and abundant floral display. Several breeders, including Dara, have used it to create other iris cultivars. He continued to dabble with irises until his death in 1992, and SBBG is pleased to introduce two more of his cultivars, ‘Canyon Bliss’ and ‘Canyon Sunshine’—both progeny of ‘Canyon Snow’. These bring to twenty-three the number of native cultivars that Dara selected, representing the most tangible part of his rich

horticultural legacy. The most obvious feature of Iris ‘Canyon Bliss’ is its size. Each violet blossom is five inches wide with a regal bearing. All three parts of the flower—standards, falls, and style arms—are violet with subtle markings of white, yellow, or turquoise. The yellow eye spot (signal) on the falls is veined with purple and the overall shape of the flower is similar to that of ‘Canyon Snow’. The violet coloration was inherited from its other parent, Iris ‘Claremont Bluebird’, a selection made by Lee Lenz of Rancho Santa Ana Botanic Garden. Mature plants can attain two or more feet in diameter and produce glorious bouquets in mid-spring. As with other PCH cultivars, ‘Canyon Bliss’ grows well in either full sun (in coastal regions) or dappled shade and is drought tolerant, yet it responds favorably to occasional summer water.

Dara’s other gift to iris lovers is the buttery yellow Iris ‘Canyon Sunshine’. The flowers, just shy of five inches in width, are etched with light brown veins and the slightly darker yellow eye spots are practically identical to those of ‘Canyon Snow’. Its other parent is Iris ‘Canyon Gold’, a clone that was also selected by Dara but unfortunately lost shortly after a limited distribution. 2 The fact that its genes live on in this new cultivar makes ‘Canyon Sunshine’ even more desirable for sentimental reasons, an aspect that many gardeners can relate to. Both of these new clones will make lovely additions to mixed borders, meadows, or woodland gardens.

Iris ‘Canyon Sunshine’

Iris ‘Canyon Sunshine’

Soothing Summer Color

As the days of summer lengthen and the sun bakes away whatever moisture remains in the soil, much of California’s flora enters an obligate dormancy that lasts until the autumn rains return. In the water thrifty garden, one looks to buckwheats, bunchgrasses, California fuchsia, goldenrods, and golden yarrows for floral and textural interest. Two other genera in the sunflower family also bring welcome color to the garden in summer: Aster and Lessingia. Both are excellent choices for attracting butterflies as well.

Several years ago, SBBG introduced Lessingia filaginifolia ‘Silver Carpet’, a prostrate, densely tomentose selection of California aster with light purple and yellow flowers that blooms profusely during the warm season. Another option for the cool silver palette is L. filaginifolia ‘Smart Aster’. What distinguishes this selection is its form; it develops into a three-foot tall and wide mound within a single year. By summer, a mantle of one-inch, daisy-like flowers covers the foliage. ‘Smart Aster’ grows best in lean soils under sunny skies and thrives in summer-dry coastal gardens. Plants will perform better with some shade and a bit of summer water in warmer inland sites. To retain a dense habit, prune it back to the crown after flowering. Since it grows so rapidly, another alternative is to simply replace it with a new plant the following autumn. ‘Smart Aster’ is an attractive counterpoint to the dark green leaves of coffeeberry (Rhamnus californica) or sugar bush (Rhus ovata), or an amiable companion for white sage (Salvia apiana), our lord’s candle (Hesperoyucca whipplei), or bigberry manzanita (Arctostaphylos glauca) in a silver garden. Its foliage color is a perfect match for ‘Canyon Prince’ wild rye (Leymus condensatus ‘Canyon Prince’).

Aster chilensis 'Purple Haze'

Aster chilensis ‘Purple Haze’

Coast aster (Aster chilensis) is an exuberant plant recommended for large spaces, with the following caveat: this aggressive native spreads by rhizomes, all the more rapidly when supplemental irrigation is provided. A prostrate, older introduction, A. ‘Point St. George’, will quickly take hold and create a dense groundcover if not nibbled by rabbits. ‘Purple Haze’, our new selection, is more typical of this species size-wise, reaching three to five feet tall when in bloom. What sets it apart are the darker purple flowers, a real standout compared to the lavender or white flowers one usually associates with coast aster. ‘Purple Haze’ has been a stalwart performer in our meadow, complementing the myriad bunchgrasses, goldenrods, and California fuchsias that make the composition hum with pollinators all summer long. An occasional touch of powdery mildew may mar the foliage; otherwise, all it needs is an annual pruning back to the ground after flowering. Installing a root barrier is advisable for confining it to a proscribed area.

Flowers of Lessingia filaginifolia 'Smart Aster'

Flowers of Lessingia filaginifolia ‘Smart Aster’

These four new introductions will be released at SBBG’s fall plant sale in October. Several wholesale growers that trial our prospective cultivars are currently bulking up their stock. The royalties we raise through licensing agreements help support our introductions program, and we welcome inquiries from other growers interested in commercially producing these native California cultivars.

  1. Fairbrother, Nan. 1974. The Nature of Landscape Design: As an Art Form, a Craft, a Social Necessity. Knopf, New York.
  2. Longview Iris Gardens nursery listed ‘Canyon Gold’ in its 1985 catalog, but the cultivar is apparently no longer extant. If anyone has information about ‘Canyon Gold’, please contact the author.