Trees are notoriously difficult to irrigate. That’s because the watering needs of trees change greatly over their lifespans. Starting with a root zone of just a few square feet and growing to cover several hundred feet, a tree’s irrigation footprint changes dramatically as it matures.

With that growth comes a wandering irrigation application zone and the potential for tree damage if not properly managed. It’s the responsibility of an irrigation designer to develop a solution that adjusts to the watering needs of a tree as it grows.

The goal of any irrigation design is to apply water efficiently to a targeted area so soils and plants can absorb it effectively with no runoff. This is a straightforward approach for a newly planted landscapes.

With trees, however, we need to think further into the future. Often, the irrigation solution must be modified over a tree’s life to ensure continual delivery efficiency and adequate irrigation management.

How can we approach an irrigation design for newly planted trees that accommodates future growth? Consider these three approaches:

• Hydrozone trees separately from surrounding plants. Trees have vastly different water requirements compared to shrubs and groundcovers. Design tree irrigation on different hydrozones and valves to ensure maximum management success.
   
• Design a system with built-in flexibility. Trees have different watering needs over time. Choose irrigation products that can be modified or retrofitted to provide a variety of application solutions. 
   
• Combine several irrigation application solutions for trees. Depending on its life stage, a tree may require different watering solutions — subsurface irrigation, bubblers, micro irrigation, sprays, and more. Design a system that provides multiple solutions for maximum flexibility, including various valves and application devices.

Trees provide tremendous green infrastructure value in any landscape project. Ensure that landscape and irrigation managers successfully promote tree health and growth by designing an irrigation system that accommodates tree irrigation needs now and well into the future.

To learn more about best-in-class Hunter tree irrigation solutions, review our Irrigating Trees Design Guide.