By Joshua Burman Thayer | Illustrations by Helen Krayenhoff
If you enjoy the pleasure of picking a lemon at home, you know the sense that we live close to paradise. Growing subtropical—and even some tropical—perennials around the Bay Area is possible because of our “warm-winter Mediterranean” climate. Microclimates in certain parts of the Bay Area allow for the successful cultivation of more subtropical trees and vines than you might suspect.
To learn more about the possibilities, I spoke with Jerob Chop of Verdant Landscape Design, a landscape designer and gardener who likes to combine California native plants with subtropical and temperate edibles in his biodiversity- and productivity-maximizing multi-storied vertical designs. I asked how he got started in this direction.
“The spark came at a time in my early 20s when I was in Maui,” says Chop. “There, I was able to surf, farm, and follow my path of a traveling plant person. I landed a gig at a 7-acre primate sanctuary food forest, where I was tasked with cultivating, managing, and harvesting from the edible jungle and keeping plants happy. It was rewarding to see the monkeys enjoy the fruits of my labor.”
Now based in the Monterey Bay Area, Jerob appreciates working in a coastline area where the moderate climate is stabilized by the Pacific Ocean and its regular soupy fog. “Just uphill from the foggy flats is a climate that’s quite similar to the East Bay hills. A convection of fog condenses each night into the hillsides, creating a climate much like a tropical highlands cloud forest,” he says.
But how do you know if your property is in one of these sweet spots? Besides that soupy fog, there should be little threat of frost and daytime temperatures that regularly climb above 70°F. These spots occur mostly within a narrow strip along the coast, which includes some of the San Francisco Bay’s eastside frontage.
Here are some perennial trees and vines we both have worked with and recommend for your East Bay garden.
This tropical vine vigorously cloaks fences and arbors as it climbs them in a single bound. It also creates copious blossoms to feed your resident pollinators throughout the summer. The plant propagates well from cuttings, which should be planted 6 to 10 feet apart. Choose a fence that gets full sun or let it grow up and over a pergola or arbor garden gateway. The tart, edible fruits are an acquired taste, but any fruit lover who catches on will enjoy buckets of sweet-and-sour enjoyment in the fall. Jerob likes to use this juice in his homebrewed kombucha, and he says Hawaiians love to condense the juice and pour it over cheesecake.
An incredibly versatile tree, the feijoa, as it’s called in its native Brazil, loves the Bay Area climate. Its summer flowers are edible and sweet, and the late-fall-ripening fruits are great for making jam. The plant handles a wide range of water budgets, from wet and lush to arid and seasonally dry, and it can be trained into a narrow area and still yield fruit. It also works well as a screening shrub for privacy. Plant two or more for optimal pollination. Choose Coolidge or Sellowiana cultivars.
This guava offers ripe fruit in December. Rugged, resilient, and fairly easy to grow, the tree reaches only 3 to 6 feet tall, so almost anyone can fit one into their yard. It likes full sun; wet, well-drained soil; and frost protection like you might get under the house’s eaves on a south-facing wall.
Avocados provide superior fat and protein, which plant-based eaters can appreciate. Made up of around 73% water, 15% fat, 8.5% carbohydrates (mostly fibers), and 2% protein, it’s a complete meal in a fruit. Each tree is a long-lasting community resource, and each home ranch and urban homestead with adequate space would benefit from planting several trees on a northern or eastern property line. Avocados need a big sunny spot to grow, and they take a few years to fruit. Cover the trees with a white sheet when frost threatens. Choose among Hass, Lamb Hass, Little Cado, Pinkerton, and Bacon, or plant several of these cultivars. Note: Avocado prefers to be planted on a 2- x 3-foot soil mound.
A notedly cold-hardy citrus, kumquat comes closest to the ancestral citrus in the wild. Vastly undervalued as a producer, its branches teem with fruit, and like no other citrus, its sweet peel is edible, which makes it a great garnish for mixed drinks. The kumquat tree stays small, so it can fit into any garden, and it even does well in a container on a southern facing deck. Note: Kumquat is hardy enough to work in the eastern parts of our East Bay counties. I have a client in Danville with a highly productive tree.
A favorite among kids, Satsuma mandarin is small, easy to peel, has no seeds, and can be ripe for picking from December until March. Among citrus, this fruit holds high value at market, making it a wonderful choice for a market garden on a small property. The tree is versatile, productive, and elegantly beautiful in the landscape, and it’s one of the best citrus for cold tolerance. Like all citrus, Satsuma prefers to be planted on a 2- x 3-foot soil mound.
The aromatic citrus called Buddha’s Hand holds serious value on many levels, not the least of which is its otherworldly shape. The oils in its skin are so high in aromatics that all you have to do is soak the fruit in a bowl of water or grate the zest into your tea for an at-home aromatherapy experience. Citron makes tasty candy similar to a lemon gummy. A simple way to enjoy it is to grate the rind into olive oil for a luxurious salad dressing. ´
Permaculture designer and educator Joshua Burman Thayer offers valuable gardening advice monthly in Edible East Bay’s e-newsletter. Learn more about his work at nativesungardens.com, and follow him on Twitter @nativesungarden.