Mediterranean Trees

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.....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. 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 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/24") 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 Horticultural Grit. You can place containers outdoors in Summer then into a cold conservatory, porch or greenhouse over Winter.

Olives grow very slowly, so don't require much pruning at all. If needed, in late Spring or early Summer, remove dead, diseased or dying branches. At the same time, thin out branches to allow light into the centre of the tree and remove any branches that spoil the shape. Avoid pruning too hard as this will result in the over-production of non-fruiting water shoots.

Container-grown plants may need additional Summer pruning to keep their size in check. When plants in containers get to about 1.5m (5ft), pinch out the tips to encourage branching.

In order to initiate flowers and fruit, Olive trees need a two-month period of cold weather (with temperatures below 10°C (50°F)). They also need a fluctuation between day and night time temperatures. Plants kept indoors are therefore unlikely to flower.

Very dry soil conditions can also inhibit flowering, even if the tree is able to tolerate such conditions. Watering during dry spells between February and May is therefore crucial for fruit production. Prolonged cold weather (below 7.5°C/45°F) can also inhibit fruit production.

Growing more than one cultivar will increase cross-pollination and improve yield, although even a single tree should produce some fruit.....Olives being 'self-fertile'.

Fruit is produced at the tips of the previous years growth, so excessive pruning will also prevent fruiting. Thinning of the crop is recommended, reducing the fruit numbers to 3 or 4 per 30cm (1ft) of branch within three weeks of flowering, in order to ensure that the crop will ripen and not drop prematurely.

Ripe black Olives can be picked and eaten raw, but taste quite different from commercially sold Olives, which are usually picked unripe and green, or black and ripe, but are then cured to produce an edible product.