Around the world, about 20 species of olive trees exist. Only the Olea europaea and cultivars varieties produce edible fruit. Olive trees grow as an evergreen in subtropical and tropical regions. Their life-span has been known to top 1,000 years. The tree grows approximately 50 feet in height with a width up to 30 feet. Most varieties are self-pollinating but cross pollination can occur.
Vigorous Growth Habits
The olive tree has vigorous growth habits. If the top of the tree is destroyed by lightning, fire or mechanical means, it will rapidly regrow using its root system, according to the University of California. The wood is also highly resistant to decay and disease. The gnarled branching growth habits of the tree make it an interesting landscape specimen.
An olive tree can be grown as an ornamental landscape specimen in regions where the temperature does not dip below 12 degrees Fahrenheit, but it will not be able to easily set fruit. Green fruit gets damaged at 28 degrees Fahrenheit, but ripe fruit is slightly hardier according to the California Rare Fruit Growers.
Olive trees grow best when planted in full sunlight. They tolerate a wide range of soil conditions and will grow in a soil pH up to 8.5. They are highly wind resistant. They require watering once or twice a month if adequate rainfall is not provided. During the winter, olive trees survive with no irrigation.
Pruning rarely bothers an olive tree. It will flourish with or without it. Olive trees can be drastically pruned to maintain height and width with little effect on the overall health of the tree. The tree normally bears fruit on the previous year's growth so care must be taken not to remove those branches or the crop will be poor.
Cultivated olive trees cannot be propagated with seeds. Cutting propagation is the surest way to recreate the parent tree. Spring softwood cuttings are the most successful for propagation. Trees grown from cuttings will bear fruit when they reach four years old.
When planting an olive tree as an ornamental shade tree, care should be taken to locate the tree away from sidewalks or other concrete surfaces because the fruit easily stains the surfaces, according to the University of Oklahoma. The fruit also can also harm grass or plant life growing close to the tree.