Water and Your Olive Trees


Water and Your Olive Trees

A Brief Guide for Watering Olive Trees

Your olive trees’ water requirements may vary dramatically from one tree to the next. But we’ll provide some very broad watering guidelines here, as well as where to find details so that you can conduct your own research to determine optimal water delivery to your tree(s).

During the growing season (May to October in Sonoma, California) water demands from olive trees increase while the amount of precipitation drops to nearly zero in this geographic area. But rainfall isn’t the only factor that plays a role in assisting olive trees to grow. The type of soil the tree is growing in plays an important role in the amount of water retention available. Also the amount of sunlight hours plays a critical role in expanding or decreasing water needs, as well as temperature.

Overall, olive trees are fairly drought tolerant. But they cannot survive or thrive without water. And if your olive tree(s) are fruit-bearing, when the tree’s water needs remain unmet, it will reduce fruit output.

olive branch in rain

Quick Answers

Olive Tree Watering Rules of Thumb

In general, start with these broad rules:

  • 1

    If your tree’s top 2 inches of soil are bone dry, it’s time to water! For newly planted trees, this often means weekly watering. But for trees established a few years, monthly watering may be more than adequate.

  • 2

    Use a moisture meter to aid you in determining how quickly water is taken up by your tree.

  • 3

    Good drainage is critical to healthy development of your olive trees, planted in ground or in pots. They intensely dislike standing in water.

  • 4

    Any browning or dropping of leaves may be an indication of an imbalance in water consumption.

Water Calculations

Calculating Olive Tree Water Needs

First, let’s take a brief look at the factors affecting water needs:

Water spewing from irrigation hose

With so many factors affecting water needs of olive trees, it’s impossible to give you one simple formula for calculating your trees’ needs. But we can provide the tools for you to make educated guesses. (And you can always phone us with your specific tree care inquiries at 707.343.6958.)

Fruiting 15 gallon olive trees
Swan Hill Olives® fruitless olive trees in 24 inch boxes
Rows of olive trees in boxes for sale
Ancient Olive Tree

General Olive Tree Water Needs by Tree Size & Age

Second, given the above factors influencing individual tree water needs, here are broad guides to begin your own testing to find the ideal water delivery amounts:

Age Size Roots Water Needs
0-1 year old olive tree 1 gallon container (before planting) 2-3 foot diameter, approx. 1 feet deep Approx. 2 gallons/week and may be as little as 1 gallon/week for under 1 y.o. tree.
5 y.o. olive tree 10 foot diameter, 2 feet deep 150 gallons/per watering
10 y.o. olive tree 16 foot diameter, 2.5 feet deep 416 gallons/per watering

You likely noticed how generalized and vague our table is. That is because there are too many variables to provide a definitive formula for water delivery to your olive tree.

The key takeaways from this table are that very young trees may be overwhelmed by too much water while becoming established. However, once established and growing larger every year, the water requirement increases exponentially. But that doesn’t mean you need to water as frequently. Perhaps you’ll need to provide more water less frequently than during the establishment period.

Water Requirements for Fruiting & Non Fruiting Olive Trees

In short, when a fruiting olive tree experiences drought conditions, the first thing to respond is a reduction in fruit production. Plants are not dissimilar to mammals and other life forms; they reduce production of nutrients for offspring when stressed. If you have nonfruiting olive trees, a lack of water will likely reduce growth.

If you are responsible for fruiting olive trees to produce the best crop possible, you will likely wish to study a number of guides for ensure your trees receive irrigation at the appropriate time for the best quality and quantity of crop. Additional resources to study are linked below.

Lastly, you should know that different olive tree cultivars respond differently to drought conditions and a lack of water. This is due to the fact that over many generations of development, each cultivar has developed different survival techniques to thrive in the specific growing conditions where it lives. Therefore, it’s extremely important to know which cultivars thrive (or not) in your specific climate conditions. If your cultivars are not ideally suited to your climate conditions, you may wish to transplant them elsewhere to thrive and/or replant with cultivars ideally suited for your climate.


Olive tree water requirements vary dramatically due to a variety of factors that provide more variables than we can distill to a simple formula. Our guide above is highly generalized. Soils are often a mix of layers, perhaps sand on top, with a clay layer two feet below. It is critical to know and understand all of the growing conditions to help you determine the ideal amount of water to deliver to your trees. We are happy to provide advice on watering and irrigation tips for your trees.

Of utmost importance is your ongoing observation of how your trees respond to the amount of water each receives. (Document frequency and amount of water delivered to help you hone your skills. Use a log!) Additionally, use available technology tools to help your decision-making. Know the annual sunlight hours received by your trees, average temperature, low and high temps, your soil & drainage composition.

How much rainfall in inches have your trees received during the winter dormant season?

The more your know about your trees’ growing conditions, the better we can diagnose and aid you with recommended improvements in care.


We strongly recommend reviewing the details outlined in some of these articles to aid you in understanding the water requirements for your home or commercial olive trees:

How can we help you?

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