How to Grow Olives – A Guide to Growing Olives
Olives are a mediterranean evergreen tree. Although they can reach a height of 9–12m (28–40 feet), they are extremely slow growing and, with pruning, are suitable for a small garden or growing in a large container.
They may produce fruit after mild summers in mild regions of the country. Once well established, olives are tolerant of drought.
Olives are not entirely hardy in the UK. If you live in a colder area of the country, try growing your tree in a large container. The tree can be moved outdoors during the summer and kept indoors, at as low a temperature as possible, but above freezing, during the winter.
- Olives may be grown outdoors if you can provide them with a sheltered, sunny position in well-drained soil – against a sunny wall is an ideal place.
- Plant into a gritty, well-drained soil. If planting into a container, use a John Innes no. 3 compost with added grit. Water well and mulch. Keep the area around the roots clear of vegetation.
- Container grown olives will need regular watering and feeding in order to produce fruit.
- Don’t over pot your olive tree – move up into a pot only slight larger than the existing one.
- Top dress with a slow release fertilizer two-three times over the growing season. During the summer, feed once a month with a multi-purpose liquid fertiliser.
- Don’t feed during the winter and reduce the watering, although don’t let the olive dry out completely.
- If you have planted your olive tree outdoors, straight into the soil, keep it well watered during the first two years or so of its life in order that it establishes well, and follow the feeding advice above.
- Pinch out the growing tips once the tree reaches about 1.5m (5 feet). Prune out dead or diseased branches in spring and thin out the centre of the tree to allow light and air to circulate. Do not prune during the autumn or winter.
- Fruit is produced at the tips of the previous year’s growth, so don’t over prune or you won’t see any fruit.
- If you’re fortunate enough to have a heavy crop, thin out the olives to three–four per foot of branch about three weeks after flowering.
- Olives turn from green to black as they ripen – they can be harvested at either stage, October–December.
Pests and Problems with Olives
- Although they are resistant to drought, olives need regular watering and feeding in order to produce fruit.
- Olives will not tolerate long spells of extremely cold weather and will suffer frost damage including leaf drop and dieback. Wrap your tree with horticultural fleece to protect from temperatures below -5ºC. Protect the roots from freezing by insulating the pot with fleece or, better still, bubble wrap and/or a thick layer of hessian. A tree growing outside can be protected with horticultural fleece in the same way – place a really good layer of mulch around its base.
- Red spider mite and whitefly can affect olives grown under cover.
Varieties of Olive
- Olives are self-fertile and one tree will produce some fruit under the right growing conditions. However, growing two different varieties will improve pollination and increase the yield.
- Make sure you purchase an olive tree suited to the UK climate.
- As well as being delicious, olives are full of antioxidants.
- Even when black and ripe, olives are bitter if eaten straight from the tree – shop bought olives are usually cured.
- To process olives, make a couple of lengthways cuts through to the stone in each olive (don’t mix green and black olives during the initial soaking period).
- Place the olives in sterilised jars and cover with water. Drain the olives and change the water each day for a week.
- After this period, drain the olives again. Make up a brine solution and pour sufficient into each jar to cover the olives. Add a layer of olive oil to each jar to keep out the air.
- Store the olives in a cool, dark place. They should be ready to eat after about five weeks and will store for up to six months. You can marinate them after the initial five weeks.