Olives are a good choice for the small garden in regions where summers are long, hot, and dry. Olives are attractive for their billowing habit, gray-green foliage, and gnarled branching patterns.
Olives are easy to care for. They require little water once established, little pruning, and have few serious pests or diseases.
All olives must be cured before they can be eaten. That said olives can be harvested from unripe (green) to ripe (black).
Where to Plant Olive Trees
Olives grow best in full sun in regions with Mediterranean-type climates, long, hot, dry summers with some winter cold. Long summers are necessary to ripen olives, at least six months of frost-free weather is best. Olives, depending upon variety, require 200 to 500 hours of freezing weather to set sufficient blossoms for a full harvest. Olives are damaged by temperatures below 12°F; the fruit can not withstand temperatures below 28°F.
Soil. Olives grow well in a wide range of soils, from sandy to loam to clay. The soil must be well drained. Olives are generally shallow-rooted plants.
Most olives are cultivated varieties, so seeds from these cultivars will revert to the original variety. That means hardwood cuttings are the preferred method of propagation. Use 2-year-old hardwood shoots taken in winter or semi-ripe cutting taken in spring or summer. Cuttings usually require four years to begin fruiting.
Pollination. Olives are self-fruitful. Climate and the tendency of olives–like other fruits–to bear more heavily every other year are the likely reasons for a small crop.
Olive Tree Care
Watering. Young olives will become established more quickly if they receive regular water. Mature olives generally are drought tolerant, but water during flowering and fruit formation will enhance the harvest.
Feeding. Olives are best fed with an annual application of garden compost or well-rotted manure around their trunks. Avoid nitrogen-rich amendments which boost green growth, not fruit growth.
Pruning. Olives that are regularly pruned will perform the best. Prune out sucker and lower branches to encourage a vase-shaped, open-centered tree. Three to five main scaffold branches work best. Olives produce fruit on 1-year-oild branches so clip out stem tips to encourage the number of fruiting laterals. Keep olives pruned to a manageable harvest height.
Pests and diseases. Olives have few pest and disease problems apart from birds that eat ripe fruit. Keeping trees healthy and pruned will reduce risk of disease and insects.
Olives come to harvest in late autumn and winter about six months after flowering. Olives can be harvest green, unripe, or black, ripe. Olives can not be eaten directly from the tree; they contain a bitter alkaloid. Fresh olives can be crushed to make oil. Olives for table consumption must be cured before they can be eaten. Black olives can be cured by brining: ripe black olives are soaked in a salt solution for at least 3 weeks or in water that is changed daily for 7 to 10 days. The olives are then heated in boiling water, drained and cooled; this process is repeated three times after which vinegar and salt (and other spices) are added to pickle the fruit. Green or near-ripe olives are cured via soaking in a series of lye solutions; they are then washed with clean water and transferred to a mild salt solution.
Also of interest: