Our Pollinator Garden in 2015
What is a garden and what is it for? The answer announces itself again and again when I go into my garden, into what was just a bare, flat rectangular acre under an often-blasting sun, and that is now a place of sustenance for pollinators and other wildlife, and beauty and drama for us. Dueling hummingbirds, the quiet melodies of gold finches, iridescent blue birds, courting titmice in the arbor, velvet upholstered queen bumblebees, Hapropoda bees zipping like spaceships through the manzanitas, and Osmia bees in the Phacelias greet a garden stroll. The perfume of daphne, osmanthus, akebia, roses, coffeeberry, and mock orange follow one through the seasons and is everywhere. In the vegetable garden, brilliant chards and deep blue kales beckon in the cool mornings, and a rainbow of tomatoes in the hot afternoons. Everywhere is sensation, scent and life. Already in early March, in northern California, nature has woken up and it resides in our garden, marching forth until the frosts of November render a quiet landscape.
I used to judge the merit, interest and beauty of a garden by its horticultural standard, and by the composition of colors, foliage textures, and the plants complementary forms. These aspects of a garden are still important, and but now my goal is to create environments where all plants can exist in sympathy with regional climates and soils, and support nature while creating a moving and inspirational experience for all who visit. The wildlife that visits the plants and flowers is an integral part of the beauty and vitality contained in the garden, a tangible aspect of it that can’t be separated from concepts of design. Pollinators are a main focus of the garden and much of it is planted for their needs with a profusion of flowering plants offering pollen and nectar resources over our long growing season. Some 30% of our food crops and over 70% of the world’s plants need pollination, yet they are often over looked when composing our gardens.
Our house and garden is in the Russian River flood plain and has compacted, silt soil about 2-feet thick over river gravel. To develop the soil structure and fertility and combat weeds, we put down corrugated cardboard and topped it with compost in the areas we wanted to plant, and mulched all the pathways with a thick layer of woodchips. We put down a grid of drip irrigation in the planted areas. We continue to top dress all the planted areas each year with compost.
The garden is edged with a variety of trees and shrubs such as mock orange, coffeeberry, California wild lilac, Toyon, vitex, Strawberry tree, manzanita, California buckeye, plus black locust, wild plums, deodor cedars and Sargent cypress, for privacy, shade and habitat for birds and pollinators. A central oval-shaped, densely planted bed occupies the middle of the site, around which a wide circular path flows. The vegetable garden is at the far, eastern end of the garden and is surrounded by a lather of flowering roses, grasses and perennials on three sides, and the tall hedgerow of trees on the fourth.
We chose plants adapted to our compacted soil and cool winter/intensely hot summer climate (Zone 8) . Rainfall has averaged 34 inches a year, but has been far less recently. Ninety-Five percent of the plants in the garden cater to wildlife, the exceptions are a few favorite double roses, daphne and osmanthus. I chose plants that provide floral rewards of pollen and nectar with a variety of bloom times to provide almost year round floral resources for bees and other pollinators. The complex structure of the perennials, shrubs and trees also provide shelter and nesting habitat for many birds. There are at least several hundred species of plants on the site, flowering from February until November when freezing weather arrives. In July I counted 55 blooming species. Diversity of floral rewards is important for both native bees and honeybee health. A walk through the garden reveals different bees on different plants, expressing bees preferences to specific flowers. In all our gardens, the same situation is true and all of them offer great potential for us to learn from. Some of the plant preferences are dictated by the number of flowers blooming of each species. A collector’s garden, with one plant of each species is not a good bee garden. Bees need at least one square meter of each to make it worthwhile visiting this plant species. These can be next to each other or repeated in the garden. Some plants have flowers that have inaccessible pollen and nectar like double roses or dahlias. Some plants just produce pollen, like poppies. Other plants are not visited by bees. therefor it is best to consult lists of bee-friendly plants before planting.
There are about 1600 species of native bees in California, and 4000 in the continental US. They come in a wide range of shapes, colors and sizes- from 1/10 of an inch long in the case of Perdita bees, to black carpenter bees that many be 1.5 inches long. They may be shiny black, black and yellow, iridescent green or covered in fur like bumblebees. Honeybees are not native to North America and were brought to the American colonies in Virginia in 1622 for honey and wax production. Most bees are generalist forages and will visit a number of different species for pollen and or nectar, though all bee species have preferences as to what flowers they will visit. A small percentage of native bees are specialist foragers, such as squash bees, and will collect pollen from one plant family. Bees need a variety of pollen and nectar sources for health, just as we require a varied diet. Native plants are best for native bees as they coevolved with these plants, but being generalists, many will visit nonnative plants as well. Not all bees can gather nectar from every flower. In flowers that have long nectar tubes like agastache, comfrey, nepeta, monardella and lavender, only large bees (including honeybees) may be able to access the hidden nectar. Small bees require easily accessible nectar, and gravitate to flowers with short nectar tubes like wild lilac (Ceanothus), or calamint (Clinopodium nepeta). Native bees species are active in specific seasons- like early spring to early summer, midsummer or late summer, while honeybees fly on days warm and dry enough- generally over 50 degrees, so you will see different bees in different seasons. Native bees are better pollinators than honeybees as they are out earlier and later in the day, earlier in the season and in rainy weather. They also move better between plant species than honeybees. Only 250 orchard mason bees can pollinate one acre of apples, a feat that takes ½-1 colony of honeybees- 20,000-40,000 bees!
Many native bees are solitary, not social like honeybees, so are not aggressive. Seventy percent are ground nesting in small holes with chambers where they make balls of pollen and lay an egg on it for larval food, then make a seal, and repeat the process five or six times. Thirty percent are crevice nesting and make or use small holes in dead wood, fence posts or hollow plant stems to construct pollen balls and lay eggs on. Pollen is a protein source and is a larval food for all bees, while nectar is composed of different sugars and serves as fuel for adult bees. Different plant species produce different quality pollens and nectars, with higher protein pollens and copious amounts of nectar production preferred by most bees including honeybees.
Our garden is densely planted, so the plants form an impressionistic froth of form, color and life. Foliage touches and intermingles and provides for pollinators, a profusion of ever changing bloom. Bloom begins in January, February and March with manzanitas, plums, flowering crabs, scarlet grevilleas, deep blue California lilac, rosemary, acacia, akebia, wild lilacs and wisteria. In May, the garden is perfumed by the exotic scent of native mock oranges Philadelphus lewesii, and has intense bee activity on the coffeeberry (Rhamnus californica) and Toyon (Heteromeles californica). A purple bee filled pool of Nepeta ‘Walker’s Low,’ and Penstemon ‘Catherine de la Mare’ swirls in the center of the garden, sprinkled with raspberry Penstemon, white Oenothera pallida, and the wild Canterbury bells of Phacelia minor). June and July are dominated by sunflowers, deep purple Agastache ‘Purple Haze’, and A. ‘Tutti Frutti,’ Salvia darcyi, Teucrium hircanicum, Pycanthemum munitum, bergamot, goldenrod, milkweeds, lambs ears, calamint, teasel, and Salvia uliginosa. Fall brings a resurgence of Salvia greggii and S. microphylla blooms, catmint, oreganos, sunflowers, Aster ericoides ‘Monte Cassino,’ and sweet autumn clematis. Hummingbirds and monarch butterflies migrate through in fall and the garden sees many visits daily of them.
In addition to planting for wildlife, we have a very productive vegetable garden entered through an old, green Victorian door and surrounded by a haze of bronze fennel, perennial sunflowers, old-fashioned roses, crimson salvias, mauve teucriums, oreganos, California fuchsia, and the orange kniphofia ‘Yellow Cheer”.
A visit in the garden reveals a scene where life is intermingled with flowers, and bees of many varieties visiting the many flowers, keeping us, and our visitors- both human and the wild, healthy and happy.
Favorite habitat plants through the seasons: (from early until late)
Manzanita Arctostaphylos spp.
Californian wild lilac Ceanothus spp.
Rosemary Rosemarinus spp.
Californian poppy Eschschlotzia californica
Desert bluebells Phacelia campanularia, minor, tanacetifolia
Viper’s bugloss Echium plantaginoides
Coffeeberry Rhamnus californica
Catmint Nepeta ‘Walker’s Low’
Perennial horehound Marrubium supinum
Angelica stricta purpurea
Lamb’s ears Stachys byzantina
Coyotemint Monardella villosa
Mountainmint Pycanthemum munitum
Pincushion flower Scabiosa ochroleuca
Agastache Agastache hy. foeniculum, ‘Purple Haze, ‘
Blanket flower Gaillardia ‘Oranges and Lemons’
Salvia ‘Mystic Spires’
Sunflower Helianthus annuas
Purple nightshade Solanum xanti ‘Mountain Pride’
Wild bergamot Monarda fistulosa
Goldenrod Solidago spp.
Oregano Origanum ‘Santa Cruz’, ‘Bristol Cross’
Aster ericoides ‘Monte Cassino’
Sedum ‘Autumn Joy’
Strawberry tree Arbutus unedo