How to Harvest From Olive Trees
Olive trees grow naturally in the Mediterranean, but also are planted in temperate climates along the West Coast of the United States. These tall, gnarled trees produce what becomes the green and black olives we eat: the green ones are not ripe, and the black ones are ripe. Olives require careful preparation before they are ready to eat; the raw fruits are inedible without soaking and salting. Before the fruit is processed and brought to the table, the olives must be picked at the correct stage.
Spread a tarp under the olive tree. Cover the ground from the trunk out to the outermost reach of the tree's branches.
Hand pick under-ripe olives that still are in the green stage if you want green olives. Grasp the stem above the olive fruit, and twist the fruit off the branch. Place it in a collecting basket. Use a ladder to reach the upper branches of the tree.
Pick fully ripened olives for making black olives. Shake the branches of the tree so the olives fall onto the tarp. Alternately, beat the higher branches with a broom to shake the olives loose.
Pick the olives off the tarp. Place them in your collecting basket. Process the olives within 48 hours of harvest so they do not over-ripen.
Hardy Olive Trees
When dormant, olive trees tolerate temperatures down to 21 degrees Fahrenheit for short periods of time. Olive cultivars are classed as sensitive, moderate and hardy according to their cold tolerance. Many of these are used for commercial oil production and are not available widely for home planting, but Arbequina, Ascolana, Mission and Sevillano are obtainable. Arbequina is self-fertile, adaptable to different growing conditions, and bears annually rather than in alternate years. Fruit are suitable for table and oil production, with oil characterized variously as sweetly green with some peppery taste, aromatic, nutty, buttery, fruity or like ripe apple. Native to Tuscany, Italy, Ascolano is one of the four most important varieties grown commercially in California. Trees are medium-sized and bear a medium-yield crop in alternate years.
Green olives respond best to lye curing, while salt curing is preferable for black olives.
Depending on the olive variety, the under-ripe fruits may be straw or green colored.
Lye is used to process most olives at home. Lye is a caustic chemical and proper care and safety precautions must be taken to avoid injury.
- Brigham Young University: Olive Tree Horticulture
- University of Illinois Extension: Olives
- California Rare Fruit Growers: Olive
- Arbor Day Foundation: Olive, European
- Olive Production Manual; G. Steven Sibbett et al.
- University of Florida IFAS Extension: Potential for Producing Olives
- The Flavors of Olive Oil; Deborah Krasner
- Olive Tree Growers: Olive Tree Varieties