The olive tree, Olea europaea, is a classic Mediterranean tree that we might associate more with holidays than our own back garden. However, they make good street trees and garden trees in the UK, with attractive pale green, evergreen leaves, slow growing habit and compact size. They can be grown in borders but make good container plants, too. There are now many cultivars to choose from that tolerate cooler temperatures, although a sunny, sheltered location will get the best results. You might even be lucky enough to get your own crop of olives – perhaps not enough for a bottle of olive oil, but certainly enough to cure and serve up as an appetiser.
Learn more about growing olive trees, below.
Where to grow olive trees
Olives are Mediterranean plants so thrive in conditions closest to the hot, dry climate of their native habitat. Choose the sunniest and most sheltered spot available – a south-facing spot with a brick wall behind it will work well.
How to plant olive trees
If you’re growing your olive tree in a border, dig a hole and add mycorrhizal fungi to help the tree establish quickly. If you have heavy soil then add plenty of grit to aid drainage. If growing in a container or raised bed, prepare a soil-based mix of compost and grit, with added organic matter and nutrients.
Most olive trees are supplied pot grown, so they can be planted at any time of the year, unless the soil is frozen.
It’s possible to grow an olive tree from seed, but this is a long process and when grown, your plant will revert to a wild variety, rather than its parent cultivar. You need heat to get seeds to germinate – sow undercover in a propagator in spring.
Caring for olive trees
Olive trees may be drought tolerant, but they need to be kept well-watered, as dry spells during early spring can affect flowering and fruiting. They also need feeding regularly with a liquid feed every two weeks during the growing season.
In severe winter weather, protect border-grown trees with horticultural fleece and a winter mulch around the base of the tree. For pot-grown trees, wrap the container with a layer of bubble wrap or horticultural fleece to protect the roots from freezing temperatures.
Olive trees are slow growing and do not need much pruning other than to keep to the desired size and shape. Prune in late spring to mid-summer, to remove dead, diseased or dying branches. Thin branches to allow more light into the centre. Although evergreen, olives do shed leaves, mostly in late spring as older leaves make way for new growth.
Harvesting and storing olives
Your olive tree may never fruit, but if it does it will take at least four years for the tree to be mature enough. Harvest the olives in late autumn.
If you’ve ever eaten an olive straight from the tree you will understand why they need to be cured. They are extremely bitter to taste. To make them palatable, soak them in a brine solution for up to six weeks (you will need to change the water regularly).
Olives trees: problem solving
Olives can be affected by extremely cold weather, below -10°C. This can cause damage to the foliage and bark. However, plants should recover, although they might suffer in terms of fruit production the following season.
Extreme wet can cause leaves to drop and may weaken the tree. This can allow other diseases, such as verticillium wilt or phytopthora root rot, to take hold. Olive trees can also be affected by honey fungus, so don’t plant in areas where this disease has been found.
Olive scab is a fungal disease that causes spots on the leaves, excessive loss of foliage and poor fruit production.
How to propagate olive trees
Olive trees can be propagated by taking semi-ripe cuttings in summer or hardwood cuttings in winter.
Olive tree varieties to try
- Olea europaea ‘Arbequina’ – a Spanish variety from Catalonia, small but vigorous, with good tolerance of frost and poorer soils.
- Olea europaea ‘Cipressino’ – a southern Italian variety, from Puglia, this has a good, upright habit and compact growth and a good choice for smaller gardens or pots. It is hardy and good for coastal gardens.
- Olea europaea ‘Frantoio’ – a classic Tuscan olive tree, self-fertile and the source of many bottles of olive oil. Easy to grow in the UK and a good choice if you want a reliable fruiting tree
- Olea europaea ‘Hojiblanca’ – a cold-tolerant Spanish variety from Andalucia, with an arching habit and leaves with pale undersides.
- Olea europaea ‘Leccino’ – a reliable Italian variety that does very well in the UK climate.
- Olea europaea ‘Pendolino’ – this compact, Tuscan olive tree, has a weeping form and is good for smaller spaces. It needs to be planted with other pollinating olives to produce fruit.