To help your tree maximize its fruit production, water it throughout the summer’s dry season. Since soils and microclimates vary widely, there is no set amount of water or frequency of watering per week that works for all locations. There are guidelines that can be followed, however, that will help in the development of an appropriate irrigation program. 

Olives are shallow rooted trees. While they do have some deep roots that reach down for stability, the majority of the actively feeding roots are closer to the soil’s surface, making deep watering unnecessary. Watering a few times per week with shorter duration is typically preferable than one long drink per week. A shovel or soil probe can be used to determine how many hours it takes to reach the depth of the deepest active roots and irrigation durations can be timed to reach that depth. Most orchards have more than one soil type and often the irrigation program is a compromise that has to satisfy many varying soil compositions.

When establishing a young orchard, information for watering according to crop development can be disregarded. In the first few years, the goal is to increase the canopy as much as possible, by judicious watering through the warm season. The vegetative growth in the initial years will help increase fruit production in the following years. A producing orchard’s water requirements will fluctuate throughout the season, according to the physiological stage of the fruit. 

It is important to make sure the trees are quite hydrated during bloom. The flowers necessitate a great deal of moisture to remain viable, as dry, desiccated pollen will not be fertile. Often during bloom there is still actively growing, green grass on the orchard floor which can look deceptively lush. This grass is using up water from the soil too, so it is crucial to provide enough water for the trees to feed their own copious blossoms. As each spring will be different, the soil’s moisture level as the buds are forming and during the blooming period should be carefully monitored.   

Like many drupe fruits, olives size up in a double-sigmoid pattern. After fruit set, the fruit grows very quickly via cell division and cell enlargement. Then there is very little change in fruit size as the pit matures and hardens. The last stage of growth is all cell enlargement as the fruit matures and finally accumulates its oil. The first stage of fruit growth (cell division and enlargement) requires a good deal of water from the tree. This period is a good time to keep the trees nicely watered. Pit hardening requires less moisture from the tree and irrigation can be less frequent in this period. The last stage requires more water again as the fruit sizes up and accumulates its oil.

A few weeks before harvest, irrigation should be reduced. Overwatered fruit is hard to mill, and being plumped up with water (and not oil), will cost more if the charge is by the ton! On the other hand, extracting oil from dry fruit is equally difficult; if the fruit is shriveling, it is too dry. Most mills prefer a moisture level between 52% and 54%. In addition to the fruit’s hydration level, the tips of the branches will indicate the stress level of the trees: turgid, erect leaf tips indicate a tree with sufficient water reserves but wilted, flagging tips are symptoms of drought stress. Butte County Farm Advisor Joe Connell's extensive research into olive orchard irrigation management is another excellent resource.

For specific advice regarding your olive trees' irrigation requirements visit our Consultations page for more information.

  1. Olio Nuovo Olive Oil - Case (375mL)

    Olio Nuovo Olive Oil - Case (375mL)

    Steeped in the Italian tradition of creating a "New Oil," our 2018 bottling can be summed in one word - GREEN. Phenomenal notes of green olive, raw artichoke, freshly cut grass, and the herbaceous flavors of bitter greens and green tea. There's an ever so slight hint of cinnamon from the Leccino olive that enthralls us. Balanced with just a bit of bitterness so you know it is Olio Nuovo with a pungency in the throat that reminds you why old traditions are good to keep. learn more »
  2. Farmers Market Gift Set

    Farmer's Market

    This gift set has our McEvoy Ranch Market Tote bag with long handles to comfortably take you to your favorite farmers' market. Can be used for trips to the bookstore, yoga studio, or whatever you'd like! Of course, the extra bonus is our AbFab Certified Organic Extra Virgin Traditional Blend Olive Oil. We recommend you take that out of the bag and use it! learn more »
  3. Olive Orchard Gift Set

    Olive Orchard

    This gift set comes with a 375ml bottle of our Tradtional Blend Certified Organic Extra Virgin olive oil, a jar of Citrus Olives (100% slow-cured Sevillano olives with fresh lemons), plus a gorgeous olive wood serving dish made in France that has a spot for the pits. For extra delight, a matching olive pick is included. learn more »
  4. Citrus Orchard Gift Set

    Citrus Orchard

    This lemon-themed gift set includes a 375ml bottle of our Lemon Olive Oil (done in the traditional Agrumato method of simultaneously crushing olives with organic lemons), a jar of Lemon Marmalade, Citrus Olives for an easy appetizer, and a hand juicer crafted from olive wood for those moments when life gives you lemons...and you make lemonade. learn more »