How Much Water Does It Take to Grow Pecans?

Northern pecans are a crop that has been grown with success in Kansas. While the varieties adapted to the cooler temperatures of Kansas do not yield as prolifically as their Southern counterparts, the flavor is believed by some to be far superior.

A common question that beginning pecan growers have is about irrigation. Just how much water does a pecan tree need?

Factors affecting pecan water consumption include:

• Tree size.
• Maturity.
• Stage of nut development.
• Air temperature.

Average Pecan Water Needs

As previously mentioned, the rate at which a pecan uses water varies with maturity. A young tree may not use any more than a gallon of water per day. At peak consumption, mature pecans may use as much as 350 gallons of water per day. Their needs are highest in August and September, when the nuts are filling out.

Depending on variety and weather, pecans need to receive the equivalent of 30 to 50 inches of rain per year for a good harvest. A water shortfall can adversely affect nut quantity, shape, and size.

The depth at which water is present in the soil is also of importance, as pecans typically pull from the top 32 inches of soil. They can pull water from further down if necessary for survival, but if they are stressed enough to draw down this deep they typically will not produce a good crop of nuts.

Irrigating Pecans

Given the fact that the wettest part of Kansas, the Ozark Plateau in the far southeastern corner of the state, receives an average of 40 inches of water per year, it follows that pecans in Kansas will sometimes require irrigation if they are to produce a large, high-quality crop.

Unless your soil is exceptionally poorly drained, you are not likely to overwater a pecan tree. A more limiting factor will probably be the amount of water available to you for irrigation purposes. Therefore, irrigate wisely. You want your trees to develop a deep, healthy root system for greater resilience in hot, dry weather.

Observe the following guidelines:

• Never water more than once a week.
• Water down to about three feet to stimulate root growth, but no farther to avoid wasting water.
• Keep weeds away from young trees to reduce competition for moisture resources.

Many pecan growers use drip irrigation to water their trees, as it can deliver moisture to the root zone effectively. If this type of irrigation system is used, moisture sensors are recommended to ensure that the soil is receiving moisture at the ideal depth.

Helpful Resource

30-Year Normals
This map will help you achieve an idea of the precipitation you can expect on average in your area.