The ‘O’ in my A-Z of garden trees is a tree that has grown in popularity in the UK in recent years, though is a little tender. I have an olive tree growing in a pot in the courtyard here at Old School Garden. It’s a couple of years old and though producing fruit, these have not yet developed into anything edible….

Common name: Olive

Native areas:  found in much of  Africa and the Mediterranean basin, the arabian peninsula, southern asia and has been naturalised in many other places.

Olive characteristics from the Kohler Medicinal Pflanzen

Historical notes: The olive tree as we know it today had its origin approximately 6,000 -7,000 years ago in the region corresponding to ancient Persia and Mesopotamia. It later spread from these countries to nearby territories corresponding to present-day Syria and Israel.

Olive oil has long been considered sacred. The olive branch was often a symbol of abundance, glory and peace. The leafy branches of the olive tree were ritually offered to deities and powerful figures as emblems of benediction and purification, and they were used to crown the victors of friendly games and bloody wars. Today, olive oil is still used in many religious ceremonies.

 Features: Olives grow very slowly, and over many years the trunk can attain a considerable diameter. One was recorded as exceeding 10 m (33 ft) in girth. Olive is an evergreen tree or shrub. It is short and squat, and rarely exceeds 8–15 m (26–49 ft) in height, and are generally confined to much more limited dimensions by frequent pruning. The yellow or light greenish-brown wood is often finely veined with a darker tint; being very hard and close-grained, it is valued by woodworkers. 

A gnarled old olive- picture by Roberta S.

Olive flowers and foliage- picture by Sputnikcccp

olive fruits- picture by Nick Fraser

Uses:  As a small tree with a rounded form, the olive can take on an attractively gnarled appearance as it develops and is a good choice for small gardens. It has small, but attractive leathery grey-green leaves and small,  fragrant white flowers. They can be grown as half standards pruned to the classical Tuscan shape, or as full standards as well as more natural forms. They can benefit from a severe biannual prune in April, but as the fruit develops at the tips of the previous year’s growth you’ll sacrifice one year’s crop. These look especially good in teracotta pots and in Mediterranean style gardens.

An Olive Tree in a garden setting

Growing conditions:  If you have a protected city garden or live in a mild area, olives can be grown outdoors as long as you give them a sunny position and plant them in well-drained soil, for example, against a warm wall would be ideal.  In cold or northern regions winter protection in a conservatory for example, will be required.

Once established they are extremely drought-tolerant, but plants will do better if watered regularly in dry spells during the growing seasons. To encourage strong growth, it’s a good idea to feed each spring with a general fertiliser, such as Vitax Q4. Olives naturally shed their older leaves in spring (April in the UK) as new growth begins.

Olives are not entirely hardy in the UK, and will be damaged by temperatures below -10°C (14°F). So, in colder areas of the country, you can grow olives in large (60cm, 24ins) diameter and depth) containers. Plant in a well-drained mix of compost, such as loam-based John Innes No 3 with 20 percent by volume added horticultural grit. You can place containers outdoors in summer and then move into a cold conservatory, porch or greenhouse over winter.

Olives ready to eat- Picture by K’m

Although they can cope with dry periods, olives in containers need regular watering and feeding to produce fruit. During the growing season keep the compost moist and feed with a balanced liquid fertiliser such as Phostrogen or seaweed, every month. In winter, you can reduce watering, but don’t let the compost dry out completely.

Olive trees can live for several centuries and can remain productive for as long if they are pruned correctly and regularly. 

The Olive Tree of Jerusalem mural

Further information:

Wikipedia

RHS- Olea europaea

Barcham trees directory- Olea europaea

‘The Olive Branches Out’- Daily Telegraph

Old School Gardener