Olive trees are one of the world’s oldest cultivated trees, dating back to ancient Greece. They’re tough, drought-hardy and famous for their delicious, plump fruit, which can be picked, pickled and enjoyed – no wonder these beauties are still popular today.
By growing olive trees, you will not only add stunning silver foliage to your garden, you’ll also have an evergreen tree that is great for topiary, hedges or even espalier. Find out how to grow an olive tree in Australia and how to care for the tree so that it produces delicious olives for years to come.
Where do olive trees grow best?
Olive trees are native to the Mediterranean, so they thrive in a climate where the summer is long, hot and dry and the winter is cool (they’re quite frost-tolerant). Not suited to the tropics, they will grow well in temperate climates and even along coastal areas.
Plant olive trees in full sun where the plant will receive at least six hours of direct sunlight. Place it in a position that is protected from strong winds or stake well.
How to fertilise olive trees
These trees can survive on poor, low-nutrient soils, provided they are well-drained. However, they will produce better fruit if planted in well-drained, fertile soil. If you’re growing in pots, use a top-quality potting mix.
Fertilise olive trees in early spring and late summer with a well-balanced fertiliser, such as Yates Dynamic Lifter Advanced For Fruit & Citrus or Osmocote Plus Organics Fruit & Citrus, which feeds the plant and enriches the soil, too.
Growing olive trees in pots
While a fully grown olive tree can reach more than 6 metres in height, young olive trees will happily thrive in a pot. Just be sure to select a large container and fill it with a nutrient-rich potting mix. You can also grow olive trees indoors, provided that they are placed in a position that receives at least six hours of direct sunlight per day.
To care for a potted indoor olive tree, top up the pot with fresh soil every couple of years and water the tree lightly but regularly.
Caring for olive trees
Watering
Water new olive trees regularly until they’re well established. Mature trees are very drought tolerant but will produce better fruit if watered well.
Pruning
To encourage growth, prune out suckers and low branches during winter, and remove the tips of stems that have grown too long. Remove dead or damaged limbs and those that cross over each other.
Harvesting
Once the tree is four or five years old, it will start to bear fruit. Harvesting generally takes place from mid-autumn to early winter. For green olives, pick your fruit when it turns from dark green to light green, or you can wait for them to turn black, but still firm, for black olives. They can be picked by hand or, for the more serious pickers, spread a sheet or tarpaulin on the ground underneath the tree, then shake the tree vigorously to free the fruit.
Pests and diseases
Keep an eye out for olive lace bugs. These are native Australian critters that suck sap from the underside of the leaves – they can completely defoliate the tree and eventually kill it. If seen, thoroughly spray the underside of the leaves with a product such as Eco-oil or pyrethrum.
Peacock spot, a widespread fungal disease, can also affect the leaves and strip the tree of its foliage. It causes sooty blotches to form on the leaves in winter, which develop into greenish-black circular spots.
To control the disease, infected trees should be thoroughly sprayed in late autumn with a copper fungicide such as Yates Fungus Fighter Copper Fungicide. If the problem is severe, spray again in early winter.
5 types of olive trees Australia
Check out these well-known olive cultivars – their fruit can be pickled or pressed into oil.
Kalamata
They produce juicy, sweet olives that are harvested once they turn black. Recognisable by their unique torpedo shape, they are ideal for cooking or eating on their own. This variety is self-fertile, but fruiting may improve if cross-pollinated with Frantoio. Height: 8m
Frantoio
Frantoio olives are usually used to make a fruity, aromatic oil. When pickled, these olives have a pleasant nutty flavour. Frantoio is a self-fertile variety that consistently produces heavy yields. Height: 8m
Manzanillo
One of Spain’s finest varieties. It’s considered the world’s best dual-purpose cultivar as its olives can be pickled when they’re green or black, and are also used to produce oil that is exported internationally. This variety is self-fertile, but may benefit from cross-pollination with Frantoio and Arbequina. Height: 5m
Picual
A medium-sized tree originating from Spain. It bears fruit early in the season that’s best picked when ripe. This variety is self-fertile but may benefit from cross-pollination with Arbequina. Height: 6m
Arbequina
Bears olives that are traditionally used for oil production, but they can also be pickled green or black. This variety is self-fertile and fruits early in the season. Height: 4-5m