Olive Trees
By Jutta Tho*rner UCCE Master Gardener
“Plants we Love”
Olive
Olea europaea
Size of Tree:10-40 feet high.
Bloom description and season: small white to cream flowers in loose clusters in the axils of the leaves. Bloom time is in the spring.
Pruning needs: mature trees 4 years and older can be pruned in late spring or summer to increase olive production.
Exposure: full sun.
Water needs: drought tolerant.
Humans have grown olive trees for thousands of years. The oldest known olive tree is 1500 years old, but the average life span is 500 years. Olive trees are loved for their fruits, eaten fresh or brined and pressed into oil. But not all olive trees bear olives. So called “fruitless” olive trees are sterile and function as beautiful ornamental trees in a landscape setting. With many varietals of olive trees to choose from, you can narrow it down to fruitless, olives for brine and oil producing. To decide between different varietals, a trip to a tasting room or deli can determine quickly which type will fancy your palate. Then, confirm that your growing and climate conditions will accommodate the tree's specific needs. If space restrictions are a concern, you can choose a dwarf tree, or grow a compatible variety in a pot. You can even care for a potted olive tree indoors. The tree's lifespan in a pot is about 10 years. Olive trees have a high tolerance for drought and do well in CA's Mediterranean climate – sunny dry summers and mild winters. Trees can survive long periods without water, but they will drop olives during times of drought. For established trees, deep watering once per month is sufficient during the summer months.
If you are planning on harvesting the olives for consumption, look out for the olive fruit fly. Trapping in sticky traps and an organically approved spray might be needed to avoid a complete destruction of your harvest. Check out these popular trees for olive oil or for brining olives: Alfonso, Amfissa, Arbequina, Beldi, Castelvetrano, Gordal, Kalamata, Manzanilla, Mission, Nicoise.
Underutilized benefits of olive trees include the use of branches in flower arrangements and using dried leaves to make a healthy tea.
