Olives are the silver leafed foundation of the Mediterranean garden palette. Native to the Mediterranean basin, the Olive has been in cultivation for thousands of years and has looked fantastic in every one of them. We use olive trees in the landscape because they are sculptural, slow growing, evergreen beauties - and versatile enough to be a focal point, repeated as a screening element, or as an allée directing flow through the garden. These trees elevate any garden space and somehow still only improve with age as the canopy fills and the trunks gnarl and twist and curl and wrap. Add to this the fact that they are almost infinitely harvestable, and but for the sake of variety it is hard to know why we even bother using any other tree. You can bring in the branches as a base for a wreath or as part of a bouquet, use the leaves for a vitamin c rich medicinal tea (it’s not particularly tasty, but it is good for you), and then there are the olives that can be cured or pressed. The reasons to have an olive are apparent, so all that’s left to decide is where to put it/them (fruit drops and creates a mess if you aren’t going to harvest) and what type do you want (allergies?). Aesthetically speaking, most olive trees look the same so the variety to plant should be determined by what you want out of your olive tree. We will break them down into three categories:
No pollen, non-fruiting
It is widely accepted that Olive trees produce a lot of pollen and that many people are allergic to it. The 'Swan Hill' variety of Olive is generally the go-to variety for allergy sufferers. Discovered in 1961 in Victoria, Australia, the Swan Hill Olive was a non-fruiting variety thought to be valuable to ornamental landscapes where falling fruit was thought messy and frowned upon. It was then brought to the United States where it was patented in 1972 by Swan Hill Nurseries LLC. In the 80s, peer reviewed studies showed that the Swan Hill Olive did not produce pollen. The Swan Hill patent has since been bought again by Devil Mountain Nursery.
"Fruitless"
The most commonly grown fruitless olive trees are 'Wilsonii' and 'Majestic Beauty'. The main difference between these and the 'Swan Hill' are that these produce pollen. As a result, it is not uncommon for these trees to produce a light set of fruit (hence the quotation marks around 'fruitless'). If you suffer allergies, these are probably not the ticket, but if you just want a tree that doesn't make a mess on your paved surfaces, then these are an excellent choice and less expensive than the Swan Hill. 'Skylark' is a fruitless variety known for being more dwarf in stature for smaller spaces.
Fruiting
Olives have been in cultivation for thousands of years so there are hundreds of varieties of fruiting olives to choose from. Given that these articles we write are generally geared towards home gardeners, we are going to focus primarily on those varieties that are good for both curing and pressing (we will leave the lamp oil harvesting to another substack). Most olives bear in alternating heavy and light years, therefore, you will not always have enough olives in a harvest to press for oil. That means that some years you will be curing your olives instead. Varieties that we think are particularly good for both eating and pressing are 'Frantoio', 'Manzanillo', 'Mission', and 'Arbequina'. When selecting Olives for fruit production, you always want to check the resources from your local grower to see what the best pollinator is for the varieties you desire. If you are really limited on space and can only accommodate one or two trees, the 'Arbequina' is the way to go because it is self-fertile (although even these will produce better with a pollinator). 'Leccino' and 'Favolosa' are the only varieties of Olive that are resistant to the Xylella bacteria, so if you are looking for your trees to be unaffected by the Mediterranean bacterial outbreak you can plant these varieties and prepare for the impending Olivepocalypse. It is worth noting that a lot of the specialty varieties are often not available in sizes larger than a 15g container, so for immediate impact in the landscape, 'Mission' and 'Manzanillo' are often available larger and have an instant impact.
Now the only thing standing (flying?) between you and your delicious olives is the olive fruit fly. Originally from Eastern Africa, the olive fruit fly is a nuisance to commercial and home orchards alike. To control infestations, remove old fruit from the tree at the end of the season. Organic pest control methods involve the use of GF-120 Naturalyte Fruit Fly Bait (Spinosad), which kills the adult flies and sprays of kaolin clay or prophylactic neem oil applications which act as a deterrent.
For more on how to cure and press olives, stay tuned!