June 25, 2016
Every year the UC Marin Master Gardeners put together a large exhibit at the Marin County Fair. This year’s demonstration garden showcases trees and plants that work in Marin’s climate zones.
From the cool coastal fog and wind in Sausalito to the summer heat and winter frost in Novato, every Marin neighborhood has its gardening selling points — and challenges. The key is choosing the right plant for the right place. Stop by this year’s “Barking Up the Right Tree” exhibit to see firsthand what thrives in your area. The exhibit is on display June 30 through July 4 at the fairgrounds at the Civic Center in San Rafael.
We live in a county of microclimates, where we can drive over a hill and have the temperature go up 10 degrees in a couple of minutes. Marin is made up of three zones, according to the “Sunset Western Garden Book,” which has delineated 24 zones in the West, which are much more descriptive of our actual climates than the USDA zones. Half of the exhibit will feature plants from inland zones 15 and 16 and the other half will display plants from coastal zone 17.
Zones 15 and 16 are influenced by marine air about 85 percent of the time and by inland air 15 percent of the time. Winter temperatures are a bit cooler in zone 15, allowing some cold winter species such as English bluebells to thrive. Zone 16 has slightly milder winters and is considered one of California’s best horticultural climates because of the presence of thermal belts that drain cold air from its slopes.
Zone 17 rings the entire bay and goes up the coast to Oregon and down to central California. This zone features wet, mild winters and cool summers with marine fog sucked in by the heat of the Central Valley. Some heat-loving plants such as hibiscus and gardenia fail to thrive, but Meyer and Eureka lemons and some oranges do well, along with plums, apples and myriad decorative plants, shrubs and trees.
Among the plants that thrive in these climates are many that attract beneficial birds and insects. Agastache rupestris, known as licorice mint in the mint family, grows 2 feet tall and produces coral spikes with purple buds along with attracting hummingbirds and butterflies. Almost all flowers will attract various bees.
Anigozanthos, commonly called kangaroo paw, comes in many shades and flowers most of the spring and summer. Epilobium canan, known as California fuchsia, blooms in reddish/orange all summer. Hummingbirds like tubular blooms such as salvia, mimulus, penstemon and heuchera, all of which come in many colors.
Butterflies are attracted to buddleia davidii (butterfly bush), cercis ‘forest pansy’ (redbud) and Perovskia atriplicifolia (Russian sage). If you want to attract specific butterflies consider asclepsias (milkweed) for monarchs or bronze fennel for swallowtails.
I usually gravitate toward plants that support wildlife in my small shady garden. Japanese maples such as acer palmatum dissectum ‘Tamukeyama’ attract birds and butterflies and are wonderful understory trees that add color and texture to any garden. Common yarrow, achillea millefolium, works as a ground cover and attracts butterflies. Arbutus ‘Marina’ is a lovely little tree with pink flowers and bright red fruit, also known as strawberry madrone, and it’s a workhorse — attracting birds, butterflies, and hummingbirds.
Bulbine frutescens is a succulent that will spread, is easily divided to share and attracts butterflies. A few years ago I put in a native Carpenteria californica ‘Elizabeth’ and it’s grown steadily and was covered with fragrant white flowers with fuzzy yellow centers this spring. Any gardener who strives to plant natives will put in at least one ceanothus — concha California lilac blooms bright blue, grows 6 to 8 feet and will tolerate summer water, unlike many other ceanothus, and attracts hummingbirds and butterflies. Quercus agrifolia, the coast live oak, attracts birds and butterflies, grows well in most of California and produces a lovely shade tree, best suited to large properties.
The good news is that you can go to the fair and see many of these plants. Enjoy improving your garden for wildlife as well as growing plants that will thrive in your zone. And don’t miss the plant sale the day after the fair closes. All plants will be on sale at the Master Gardener tent from 8 to 11 a.m. July 5.