How to Grow an Olive Tree

The olive is not a demanding plant — what it really asks for is the right place and patience. A tree planted in the wrong spot will not bear, however carefully it is tended.

Climate

The olive wants a Mediterranean climate: mild wet winters, hot dry summers. Two limits matter:

• Cold. A mature tree can survive a brief -7 °C, but prolonged hard frost kills branches and young trees outright. Olives do not grow where winters are severe.
• Chill requirement. The olive needs a spell of winter cool in order to flower. In hot climates with no winter the tree lives but sets no fruit.

Soil

The olive does well in stony, calcareous, poor soil. The real requirement is drainage: in heavy, water-holding clay the roots suffocate and the tree rots. That is why it favours sloping ground.

It tolerates a wide pH range (6-8 causes no trouble). It does not want heavy feeding; excess nitrogen makes leaves, not fruit.

Planting

Saplings go in in spring or autumn, avoiding winter frost and the peak of summer heat. Dig the hole twice the width of the root ball; gravel at the base helps drainage. Traditional groves space trees 6-7 metres apart; intensive planting is closer.

⚠ A single tree may not fruit. Some olive varieties are self-sterile, and many bear markedly better with cross-pollination. Planting at least two different varieties matters for yield.

Watering

The olive withstands drought, but it will not crop heavily without water either. The critical periods are flowering and fruit set. Young saplings are watered regularly for the first two years; an established tree needs support only through long droughts. Overwatering dilutes the fruit and lowers oil content.

Pruning

Pruning an olive serves three purposes:

1. Letting light in. Fruit forms on branches that see the sun. The centre of the tree is opened out; the classic aim is a crown "a bird could fly through".

2. Renewal. The olive fruits on the previous year's growth, so clearing old wood encourages new shoots.

3. Evening out alternate bearing. Regular pruning softens the heavy-year / light-year swing.

Prune in late winter or early spring, once the danger of frost has passed. Suckers from the base are removed throughout the year.

When does it fruit?

First fruit usually appears three to five years after planting, and economic yield takes seven to ten. In return the tree lives for centuries and still crops in its hundredth year. Whoever plants an olive tree rarely sees all of its fruit — which is where much of the plant's cultural meaning comes from. More in the history of the olive tree.

Olives in pots

The olive will live in a pot and is common as an ornamental. It then needs a wide, deep container, very good drainage and protection from winter cold. No serious harvest should be expected from a pot.