Native Penstemon and Erigeron blooming at a project site in the North Bay.
Our firm works in the San Francisco Bay area. California is living through a remarkably severe and long-lasting drought. Water is always on our minds, and it becomes especially significant when our clients ask us to create outdoor places that can still exude a colorful, lush and verdant vibe while minimizing water use.
As we face the many challenges with our drought, this article will focus on one aspect of design for Dry California: How to develop a plant palette to capture the feel of an East Coast summer garden while still staying on a West Coast water budget.
As a transplant myself, if there is one thing I miss about the East Coast and my time in northern Europe, it is the flush of deep greens and rich, colorful flowers that mark the spring and summer seasons. The East can keep their winters, but I will borrow their leafy ways to translate the look with locally adapted species for a Northern California garden.
In my discussion I will make a note of how I generally rate each plant’s “lushness” factor. While nothing will be a one-for-one translation of the East Coast’s hydrangeas and azaleas, I will try to rate how verdant these plants feel with limited irrigation.
Source: Dave’s Garden – Lantana ‘Bandana Pink’
The first plant on my list is part of a new line of cultivars from an old, reliable garden plant, Lantana camara. The Lantana ‘Bandana Series’ contains excellent new introductions that do not turn into the massive, garden-devouring monsters like their forebears could become. I especially like Lantana ‘Bandana Pink,’ with its compact mounded habit and nearly year-round pink with creamy-yellow centered flower clusters. It thrives in an informal cottage garden alongside drifts of Lavender, a tropical poolside garden next to white Fortnight Lilies, or as a bedding plant among an orderly parterre of Myrtle or Germander. The medium green leaves give the plant high marks on the lushness scale.
Source: Wikimedia – Anigozanthos ‘Bush Pearl’
A second plant with a long blooming season and true-pink flowers is the ‘Bush Pearl’ Kangaroo Paw, Anigozanthos ‘Bush Pearl’. Like the ‘Bandana’ Series’ cultivars of lantana, the cultivars in the ‘Bush’ series of were bred from much larger-growing parent species. The unique flowers, and grass-like leaves make Kangaroo Paw a choice that can span many garden styles. In more traditional gardens, it can fill the niche of irises and lilies. It will be green and colorful all-year-round. It’s medium green leaves also give it a high rating on my lushness scale. Deadheading will help keep this plant looking its best. Keep in mind that along the California coast it is a low-water use plant, but where temperatures regularly get hot it will require more supplemental water.
Source: Greenhouse Product News – Lavandula x intermedia ‘Phenomenal’
A good foil to the pinks and whites mentioned above can come from the cool violets and purples of the sage family. There are many options, but nothing beats the summer flowering of lavenders. The Bay Area’s finest gardens harbor a number of excellent Lavender species, including the long-blooming Spanish Lavender, Lavandula stoechas, but a great, new, summer-flowering Blue Lavadin, Lavandula x intermedia ‘Phenomenal’ has caught my eye.
It’s lightly frosted, healthy leaves satisfy my need for green, while its rich, cool flower color can keep any garden from feeling parched. Like the older ‘Provence’ Lavadin, it carries dense, purple flower spikes in the summer. But unlike most other Lavadins, its flowers remain upright and its branching remains tight. All lavenders to varying degrees have a silver cast to their leaves, but with their rich, cool flower colors right in the heat of summer, they still maintain a fairly high lushness factor in my book.
Source: Arborix – Convolvulus cneorum
The Morning Glory family has a pair of great species for the Bay Area summer garden: Convolvulus cneorum, Bush Morning Glory, and Convolvulus sabatius, Ground Morning Glory. Both hail from the Mediterranean. From the European side of the sea, Bush Morning Glory forms a mounded, small shrub that is covered in perfectly round, crisp white flowers for most of the growing season. Bush Morning Glory can be used in the landscape just as one would smaller landscape roses, hydrangeas, or any other moderate-sized bedding plants.
Its North African cousin, Ground Morning Glory, is a trailing plant, rarely getting over one foot tall. It works great in the foreground or as small-scale groundcover. Again, its flowers are perfectly round disks, but instead of white, they are a nice shade of lavender-blue. Like the plants mentioned above, these Morning Glories can out-bloom most other flowering plants and can form the backbone of a summer garden. They like our dry summer conditions, and can be short lived if they get overwatered. Both have leaves that are a light green with a slight silver cast, giving it a moderate-to-high lushness rating.
Source: The Frustrated Gardener – Convolvulus sabatius
Finally, plants from a new series of hybrids derived from Salvia microphylla x greggii are putting out flowers with the abundance of most bedding annuals while maintaining their low-water, Southwest-native ways. The Heatwave™ Salvia Collection contains a number of colors that range from red (‘Blaze’) to white (‘Glimmer’). I especially like the pinks in this line (‘Sparkle,’ ‘Blast,’ ‘Sizzle,’ and ‘Glitter’). The abundance of color options means that there are varieties that will pair with any color palette. Oh, and unlike many low-water sages, these plants have perfect apple-green foliage, so they again score high marks on my lushness scale.
Source: Pride of Place Plants – Salvia ‘Sizzle’
I hope that these flowering plants can inspire you to transform your own summer garden into one that is well adapted to our dry California climate. All of these plants can outperform most of the old garden mainstays in flower production while also taking the drought largely in stride. Whether they are combined to form colorful borders, or used en masse to create a sweep of color, I get excited every time we have the opportunity to add them to our designs.