Irrigation Systems; system details, layouts, and brand recommendations.

Week 2 of a 3 part blog series, to introduce you to all things irrigation. Including irrigation system details, layouts, and brand recommendations along with irrigation fun facts and handy tips and tricks!

Week 2: Irrigation system brands, system details and layout examples.

During our last post Introduction to Irrigation Systems, we went over a few basics of watering your garden with irrigation systems. This week we’ll cover more in-depth examples of types of irrigation systems, provide visual examples of what an irrigation system in your garden may look like, define irrigation system vocabulary and self-installation notes, and provide irrigation system brand recommendations. Let’s start with irrigation brands!

Which brand should I buy?

Garden Girl’s suggested Irrigation System brands for the homeowner installation: Rainbird or Hunter Irrigation

In Garden Girl’s experience, Hunter irrigation holds up better than Rainbird over a 15 year period. Please note that both of these companies have excellent videos to help visual learners learn how to install a system.

Download your FREE Irrigation Quick Reference Guide

Here are a couple of examples of a Rainbird system overall layout before we nerd out on the components:

Layout: Start with the longest side. Create parallel rows to fill the area. Identify supply and exhaust header locations, and connect the lines. Use returns or branches to follow curved edges.

• Slopes: Lay inline tubing perpendicular to the slope (parallel to contours). In flat areas, lay tubing in straight lines, accommodating curved edges by returning or branching lines.

• Edges: Hardscape edges and limits of planting are subject to wind, radiant heat, reflected sunlight, and other factors that increase evaporation and plant water needs. Place perimeter lines close to edges, typically ¼ of the regular on center spacing, but not greater than 4".

Two more examples of irrigation systems in planting beds with notated components. Pictured left (Rainbird System) Pictured right (Hunter System).

Below is an example of a vegetable bed irrigation layout.

Here is an example of a Hunter drip system in a planting bed.

Let’s talk about the components of an inline drip system.

Controller: A controller is the “brain” of every irrigation system. Wall mount or in-valve-box battery controllers are ideal.

Zone Control Kit: Every successful inline drip irrigation zone starts with three items: zone control, filtration, and pressure regulation.

Valve: A remote control valve is typically used to automatically activate inline drip systems. Alternatively, a manual valve or even hose bib may be used for non-automatic systems. Each hydrozone should be irrigated by a separate valve. Hydrozones are areas with specific conditions that affect irrigation, including plant type, spacing, density, microclimate, exposure, and slope.

Please follow all local requirements to prevent backflow and back-siphonage. Filter Filtration must be provided for all inline drip systems, regardless of water supply type. Potable water contains suspended particulates which may clog inline emitters. Filters also help reduce biological contaminants. For large or distributed systems, consider a disk filter near the point of connection. This provides a single, easily maintained item in an accessible location. Use screen filters at each drip valve as a secondary level of protection in case any debris enters the irrigation system downstream of the primary filter. Use a filter with a minimum filtration level of 120 microns (approximately 120 mesh, or 0.125 mm). Inline Drip Tubing Inline drip tubing consists of tubing laid in parallel rows. This creates a grid of emitters evenly spaced throughout the entire irrigated area.

Pressure Regulation: All of the Hunter inline drip products feature built-in pressure compensation, allowing an inlet pressure of 15-50 PSI. For mainline pressures exceeding 50 PSI, use a pressure regulator downstream of the valve and filter

Depending on the type of system you buy you will purchase the appropriate Laterals, Supply Header, Barbed Fittings, AVR valve, exhaust header, Flush Valves, and PLD Cap

*Note: Flush valves s are required on every inline drip system and must be located to provide an outlet from every point in each zone. Regular flushing not only removes debris and particles from the tubing, but the high volume of turbulent water during flushing also helps dislodge biological growth. Flush valves can be either automatic or manual. The Hunter PLD barbed valve is an affordable option to flush the system. FLUSH VALVE Manual or automatic EX exhaust header serves to equalize pressure and flow between runs of inline drip tubing and provide an outlet path for flushing. The exhaust header does not need to be sized to equal the supply header but must be able to accommodate the flow rate of the flush valve, without exceeding 5 FPS.

Layout: Typical zone layout consists of supply header(s) and exhaust header(s) with parallel lines of inline drip tubing between. These may be either center-feed or end-feed configurations. Zone design and line layout follow these basic principles:

Maximum length: To adequately supply all emitters, do not exceed the maximum run shown in the tables below. Remember to add the length of all branched runs. • Line spacing: Spacing should not be greater than shown in the tables below, but maybe reduced as required to equally space lines within a zone or provide additional coverage.

Note: Increased spacing on the EMITTER FLOW RATE – 1.0 GPH lower third of slopes is an exception to this guideline.

Hunter’s graphic for Emitter Rates

Spacing for Soil types

For Installation please follow the manufacturer’s instructions.

• Keep all pipes and fittings clear of dirt and debris, protect exposed ends by taping or plugging while assembling other components • Flush the system thoroughly prior to installing the last connections on every header • Install all inline drip products at an even depth throughout each zone • Use loop-type galvanized fabric staples or pins to keep tubing or mat in place • Verify the location of each air/vacuum relief valve in field, ensuring one is installed at each localized high point

Leak Testing Prior to backfill, the installed areas should be tested for leaks. Every zone should be operated for 20-30 minutes and observed. Wetting patterns should be regularly sized and evenly spaced. If using an Eco-Mat distribute equally. If any leaks are observed, they must be repaired. If this test is not possible prior to backfilling, it should still be conducted prior to planting. Run each valve until wetted areas appear at the surface and follow the same procedure above.