Story by Brian Barth
Olives are a rare edible with aesthetic qualities that are second to none. It’s hard for an olive tree not to be good-looking. Those satiny smooth leaves have silvery undersides that make the trees shimmer in the wind. (The silver is actually a layer of fuzz, formed by special structures called trichomes, that helps prevent water loss.) The tree’s branching pattern is supple and symmetrical in youth, aging gracefully into a sparse, gnarled form with age. A mature olive tree, should you be so lucky as to inherit one, has an iconic presence that makes it an automatic centerpiece in the landscape.
A number of sterile Olea europaea cultivars have been developed to allow those gardeners who find the fruit a nuisance to still enjoy the visual qualities of the species. It is true, olives leave a purple-black stain wherever they fall, but this drawback disappears when the tree is properly located in the landscape. Site fruiting olives away from patios, sidewalks, driveways and other surfaces. They pair perfectly with a groundcover of clumping grasses or perennial herbs, like rosemary and lavender. Full-size varieties may eventually reach 40 feet in height, though even when ancient—olive trees can live for hundreds, even thousands of years—they cast only light shade.
Like figs, grapes, pomegranates and their other geo-cultural cousins hailing from the Mediterranean Basin, olives prefer dryish, lean soil and a long, hot summer to ripen to perfection. Give them a south-facing exposure in a xeriscape planting; once established they need irrigation only during periods of prolonged drought. Olives are evergreen, and the smaller cultivars, such as ‘Arbequina’, ‘Arbosana’, ‘Koroneiki’, and ‘Picual’, are easily maintained as a head-high privacy screen. ‘Pendolino’, with its weeping willow-like branches, is one of the most striking varieties. Olive cultivars can be self-pollinating or self-unfertile, but they all are considered more fruitful when planted in a mixed grove.
A single tree usually produces more than enough olives for a family to enjoy throughout the year. The self-pollinating ‘Mission’, the classic California courtyard olive, is a good choice if you’re planting just one—and it can even make you self-sufficient in olive oil. A healthy full-size tree produces anywhere from 15 to 500 pounds of fruit in a year, depending on the weather and a host of other factors, of which 15 to 30 percent is oil. Roughly speaking, you need about 15 pounds of fruit for a gallon of oil. The challenge, of course, is getting the oil out of the fruit. Home-scale oil presses are available, but expensive. If you live in an olive-producing region, contact your local commercial presses—they often have a day set aside for hobbyist growers to bring in their olives.
It is also important to note that olives have a fairly limited growing region. Cold hardiness varies by cultivar, ranging from 10˚ to 20˚ (F), though flowers and fruit are both damaged around 28˚ or 30˚. However, the smaller cultivars can be grown in a large tub and brought indoors for winter. Olives thrive and produce fruit better than most plants when their roots are confined. You’ll have to harvest your olives green as they don’t reach their fully ripened state until late fall. Happily, that’s a fully acceptable, and common, approach.
How to cure olives
Olives are rich in bitter alkaloids, making the fruit inedible in its natural state—one reason gardeners hesitate to plant fruiting varieties. Stories about lye baths and complex sequences of stirring, heating and cooling tend to scare people away from “curing” their own olives, which is a shame, because it is a fundamentally simple process. Curing olives with lye produces the least bitter olives in the shortest amount of time, but there are much simpler methods with equally delicious results. Soaking the fruit in water, changed daily, for a couple weeks is the easiest option. You then soak them in a brine of salt, vinegar and herbs and leave them in the refrigerator to snack on. Many variations on this basic process are available online; start with this University of California publication.
Image credit: Jacques Pault/Shutterstock