Celebrating the Mighty Olive Tree
Both adored and controversial, this desert-loving tree provides beauty, shade and fruit.
One of the earth’s most ancient plants, the olive tree (Olea Europa) dates back millennia, originating, scientists estimate, 20 million to 40 million years ago in the geographic region of the Mediterranean Basin. The species is remarkably hardy and long-living—located in a tiny village in Greece, one specimen, known as the Olive Tree of Vouves, is believed to be at least 2,000 years old and is still producing fruit. In various cultures, the tree is a symbol of wisdom, fertility, power and purity; its branches are a widely recognized emblem of peace.
Arizona’s desert climate is favorable to the olive tree’s fruits, which mature in the summer heat and are generally harvestable beginning in October. While many love the tree’s craggy, twisted branches and silver-green foliage, others are put off by the plant’s spring pollen and fall fruiting. “Olives are dioecious, meaning there are separate pollen-producing (males) and fruit-producing (female) plants,” explains horticulturist Kelly Murray Young. “The pollen generated by the male trees can be an issue for individuals with respiratory issues.”
Since 1986, a Phoenix city ordinance has declared selling and planting male olive trees a public nuisance, citing “large amounts of allergenic, airborne pollens that are noxious and contribute to human disease and health problems.”
Along with the pollen-related health concerns, many olives grown in Arizona landscapes fall to the ground, creating additional hazards. “They stain sidewalks and shoes, and the pits can act like ball bearings underfoot, making walking surfaces dangerous,” Young says.
Perry Rea, owner of Queen Creek Olive Mill in Mesa is, understandably, a staunch supporter of the species. “I think that the olive tree gets a bad rap here in Arizona,” he says, maintaining that the embargo is extreme. “The windborne pollen is heavy but only travels about 100 feet and lasts just two weeks per year. There’s a lot of pollen in Arizona from pine trees, citrus and noxious weeds. The planting ban really hasn’t solved anything.
“I believe that olive trees are a gift from heaven,” Rea continues. “They have such a long life and you can do so much with them. There’s the fruit, of course, but they’re also a beautiful, versatile landscape accent. You can grow them in bonsai form, manicure them into topiaries or let them go wild. They are also great shade providers.”
In addition to the tree’s Mediterranean aesthetic, they have the added benefit of requiring minimal care and upkeep. Treat them like any other fruit-bearing tree, Rea advises. “The maintenance is basic: irrigate, fertilize and prune on the same schedule as citrus trees.” If left untended, the species will take on its natural bushy form, which can be mitigated by removing any suckers and shoots that pop up. “There’s an old saying in Italy that if a bird can fly though your olive tree, you have pruned it correctly,” he says, adding that keeping trees at a height of about 10 feet will facilitate harvesting.
For gardeners who would like to minimize their trees’ fruit production, Rea offers a simple alternative to spray sterilants, which can be harmful to the environment. “By blasting the blooms with water and washing off the pollen, you can reduce a tree’s fruiting by as much as 80%.”
FROM TREE TO TABLE
Of the hundreds of known cultivars, the Mission (Oleo Europaea ‘Mission’) and Manzanillo (O. Europaea ‘Manzanillo’) are the two most common fruiting varieties found around the Valley. “If you’ve got a fruit-producing olive tree in your backyard, most likely it’s one or the other,” Rea says, noting that worldwide, the Manzanillo olive is most frequently used for curing.
Fruit picked from the tree will have a very strong, bitter taste. “Any olive you find is edible, but in order to be palatable, they must be cured,” says Rae. “The process is relatively simple. You just need fully ripe fruit, a little time and patience.”
While the idea of making oil from your own tree might be a romantic notion, the procedure is likely more laborious than most home gardeners realize. At least 500 pounds of fruit are required to make about 20 gallons of oil. “You can’t get that from one or two trees,” says Rea. “Curing the fruit is far simpler than pressing for oil.”
Operation Olive Rescue
In the early 1960s, when a stretch of Camelback Road was being widened, Paolo Soleri noticed a number of mature olive trees lining the street that were destined for the wood chipper. After a conversation with his project foreman, the architect was granted 48 hours to rescue as many trees as he wished. Enlisting the help of a trio of apprentices who worked all night by the light of Soleri’s Volkswagen van and through the following day, six sizable trees were transported back to the Soleri’s Paradise Valley design studios and primary residence by means of a borrowed truck with a small boom crane.
Sixty years later, the six transplants are thriving, have produced fruit every year since they were relocated, and have spawned more than 40 offspring residing at both Cosanti and Arcosanti in Mayer. “It’s a great story, and speaks of Paolo’s frugality and love of nature,” says Cosanti Foundation director of marketing and communications Kelly Bird. “We have some grainy film footage of Paolo—wearing only a swimsuit and flip flops—following behind the truck on foot, trying to lift the dragging branches to protect them from damage.
“There is a reverence for those trees among our staff,” Bird continues. “They are very much a part of our identity. It makes me smile to see visitors touch the branches and leaves and ask questions about them—and then go home with a bottle of olive oil made from the fruit of those same trees Paolo rescued long ago.”
HOLD THE FRUIT
For homeowners who would like to bring the olive tree’s Mediterranean aesthetic to their landscape without the accompanying fruit drop, consider these nonfruiting, nonpollinating varieties:
- Swan Hill (Olea europaea ‘Swan Hill’): This tree thrives in full sun
to partial shade and is an excellent choice for shading a patio.
30’H by 30’W.
- Wilsonii (O. europaea ‘Wilsonii’): This cultivar of the Manzanillo can live for hundreds of years. 25’H by 25’W.
- Majestic Beauty (O. europaea ‘Monher’): Elegant and hardy, this variety has a wide shade canopy. 30’H by 25’W.
- Little Ollie (O. europaea ‘Montra’): Ideal as a potted specimen, for lining walkways or as a sheared hedge. 6’H by 6’W.