Acacias are among the showiest blooming trees we can grow in the Bay Area. Fuzzy golden orbs and cylinders emerge suddenly on many species from winter into spring. Because these spectacular blooms often coincide with the shedding of airborne pollen by pines, oaks, and cypresses, people think they’re allergic to acacia, but usually it’s the conifers and oaks that are causing all that itchy sneezing.
A flowing 15-gallon-size Acacia boormanii was the first to go gold here in the nursery this January — and admiration seems to be trumping complaints about allergies. The profuse lemon-yellow flowers smother the lush mass of fine, grey-green phyllodes (leaflike structures common to many acacia species). This species is useful as a multi-stemmed screening tree, growing to about 15-feet tall but keeping foliage to ground level. It’s amenable to hard pruning nearly to the base every few years, or to training up into a cluster of sculpted trunks with clouds of foliage above. It will tolerate clay soils, and thrives in deep, well-drained soils. A little bit of summer water, especially inland, will keep it looking gorgeous.
The intensity of acacia bloom in midwinter always comes as a jolt. The invasive Acacia dealbata, ubiquitous in suburban areas of the Bay Area and elsewhere in California, produces acid-yellow masses of flowers starting sometimes as early as December. (On the French Riviera it’s celebrated as “mimosa.”) You see similar flowers on the common San Francisco street tree, Acacia baileyana, offset by feathery, purple-grey leaves. The color grabs attention like a visual siren.
The hairy wattle (you wonder why we stick to botanical Latin?), Acacia vestita, is another of our favorites, planted at the front gate of the nursery.
By contrast with Acacia boormanii’s fluid, cloud-like form, Acacia vestita’s shape is unmistakable. Its weeping, ropy branchlets hang nearly to the ground, especially in youth. They bear silky blue-grey phyllodes in the shape of tiny, pointed, gibbous moons that contrast beautifully with the apple green skin of the branches and trunk. Growing quickly to 12 to 15 feet in height and width, it looks a bit like a green Mr. Snuffleupagus from Sesame Street. Okay–it’s a lot prettier than that, but there is a resemblance. Like most Australian acacias, it’s drought-tolerant and requires no fertilizer and will tolerate temperatures into the low 20s Fahrenheit.
Splashes of fragrant winter gold emerging now feel like that moment when a free dessert comes compliments of the chef. On top of a perfect meal, we didn’t expect or need it, but boy is it delicious.