How often to water olive trees in California

In July, established olive trees in loam need a deep watering about every 20 days in the Central Valley, about every 27 days on the south coast and about every 22 days in the South Inland zone. Sandy soil holds less water, so waterings come closer together. Clay stretches them. Check the soil before each watering and skip one after a soaking rain.

In July in the Central Valley, established olive trees need about 2.7 gallons a day under a 10 foot canopy and about 11 gallons a day under a 20 foot canopy. Give it in deep waterings spread days apart rather than a little every day, so the whole root zone gets wet.

Yes. WUCOLS rates olive trees separately for each of the six California climate zones: low water in the North-Central Coastal zone, low water in the Central Valley zone, low water in the South Coastal zone, low water in the South Inland zone, low water in the High and Intermediate Desert zone, low water in the Low Desert zone. The monthly table above shows how the same rating translates into different gallon amounts as reference evapotranspiration changes.

Yes, and it is the most common mistake with landscape olives. Roots sitting in wet soil suffocate and invite root rot: leaves yellow and drop, growth stalls, and branches can die back even though the tree is getting plenty of water. Let the soil dry well between deep soakings and fix any drainage problem before adding more water.

Keep the root ball evenly moist through the first summer while roots grow into the surrounding soil. Check the top of the root zone in warm weather and soak deeply whenever it dries. From the second growing season, stretch the intervals and water a wider ring, until the established tree needs only occasional deep soakings in the warm months.

Drip suits olives well. Place emitters in a ring near the drip line rather than against the trunk, then add emitters and move the ring outward as the canopy grows. Run the system long enough to wet the soil deep into the root zone, then let it dry before the next cycle. Short frequent runs keep roots shallow and the surface damp, which olives dislike.

Usually not if it is in the ground. Winter rain covers the cool season in most of the state, and the tree slows down then and takes up little water. Step in only during a long dry warm spell, and keep checking containers, which dry out even in winter.

Check the soil first. Yellow leaves over damp ground point to overwatering or poor drainage, the top cause of olive decline in gardens. Olives also shed some of their oldest inner leaves naturally, mostly in spring, so a light drop on an otherwise healthy tree is normal. A thirsty tree looks different: dull gray, folded leaves above soil that is dry deep down.

Yes. Drought stress around bloom and fruit set makes a tree drop fruit, and dry midsummer soil leads to small, shriveled olives. Deep soakings through the heat improve fruit size on fruiting varieties. If you grow a fruitless landscape cultivar, the tree can stay drier, since fruit quality is not a concern and the tree itself handles drought well.