Arbequina (Olea europaea "Arbequina") is the olive variety grown commercially in California. Loaded with oil, it is especially prized by the olive oil industry. It's a frost-hardy, pest-resistant tree, growing to a height of 20 feet, with a 12-foot spread. Although it is hardy to zone 8 on the U.S. Department of Agriculture Hardiness Zone Map, Arbequina can be grown in containers indoors in colder areas and kept to a manageable size through pruning.
Grow Arbequina In-Ground
Water the Arbequina deeply -- to a depth of 10 inches -- once a month during the summer. In areas with particularly hot summers and little rain, you may need to water more often. The Arbequina is drought-tolerant but does better with moisture.
Top-dress the soil around the olive tree with a 3-inch layer of mulch. Place it 6 inches away from the Arbequina's trunk and spread it out 3 feet in all directions to discourage weed growth.
Feed the olive tree as soon as you see new growth in spring with 1 to 2 lbs. of ammonium nitrate, sprinkled on the soil at the dripline. Water to a depth of 10 inches after fertilizing.
Cut off any branches that grow below 3 feet. This is the only pruning required unless you want to prune for size.
Remove suckers -- small growth that appears at the base of the tree or from the soil. When small, suckers can be snapped off by hand. Use pruning shears to cut off larger suckers.
Grow Arbequina in Containers
Allow the soil in the container to dry to 2 inches before watering the Arbequina olive tree. Double that depth in the winter.
Dilute 17-6-10 fertilizer to half strength and apply it to the Arbequina olive tree every three weeks in spring and summer. Discontinue fertilization in winter. Water the soil before applying fertilizer.
Prune the Arbequina olive tree at the end of winter to keep it to the size you desire. This tree blooms on the previous season's growth and doesn't bloom on the same wood twice. It tolerates heavy pruning, so remove as much as you need to.