Your Questions

I’ve heard of a “rain switch”, do they work and where can I get one if they are effective?

I don’t have a lot of time to fiddle with my irrigation system.  It seems to work ok, but I need to save money where I can on my utilities.  Is there something quick and easy I can do?

Every time the sprinklers come on water runs down the gutter at the bottom of the hill. Our neighbors said we should rip out the sprinklers and put in drip irrigation, do we have to do that?

I want to plant some spreading groundcovers on the slope behind my house, what is the best way to irrigate them?

We moved into a house with a Toro ECx timer. The book that comes with it is confusing… can you help me set it up?

I have an automatic irrigation system and the irrigation is coming on every day.  Is this right, how do I know how often to irrigate?

Our gardener “fixed” our irrigation system last week, and now there is a different kind of pop-up sprayer in the lawn.  Is this right; does this make a difference?

How do I know when I have the right amount of sprinklers?

John's Answers

Billy A.  from Temecula, California writes

“…I want to plant some spreading groundcovers on the slope behind my house, what is the best way to irrigate them?”

Irrigation Essential's Response:

Billy,
Great question—the trick to irrigation on slopes is to put the water on slowly so it won’t run off.  You can easily imagine a very gentle rainfall, perfectly soaking that slope – as well as imagining a heavy rainfall immediately running off and creating erosion in the process.  This answer has a hardware component, scheduling component and a soil component.

Hardware

Different irrigation heads have different “precipitation rates”, or rates they apply water.  Different soils have different intake rates, or “infiltration rates”.  The goal is to match these as best you can.  The safest bet is to put water on as slowly as possible.  Rotors, multi-stream rotors, or mini-sprinklers have the lowest “precipitation rates”.  Rotors shoot a fixed stream, and slowly rotate over the arc you can set.  Multi-stream rotors shoot light, “fingers” of spray.  The major manufacturers all make decent rotors.  We like the Hunter products – they have a “family” of rotors for all size areas, and an excellent track record with this type of hardware.  The most common type of irrigation hardware – the pop-up fixed spray head, and impact heads are not good choices for this application!

Soil and Scheduling 

Heavy, clay like soil is the most problematic soil type to irrigate on a slope.  Turn the system on and note the time on your watch.  Observe closely for signs of run-off.  When you see water beginning to run-off, look at your watch and stop irrigating!  Take a couple minutes off that run time, and make that the maximum length you irrigate that slope.  With a soil probe (mail order for a soil probe: http://www.gemplers.com or http://www.benmeadows.com) or shovel see how far the water penetrated.  You may need to irrigate again (add one or more additional cycles), after the first cycle soaks in --remember you are trying to replenish a root zone. 

Avoid Run Off – Cycle and Soak!

So for slopes – avoid run-off, then cycle and soak.  As a default number, use a 1-hour soak time. Email us back if you are having trouble programming multiple “start times” on your irrigation controller.

Soil Biology and Horticultural Practices help manage water use!

You can use less water, and have a healthier landscape by building your soil.  Please see our article “Living Soil” for more detail on soil building.  Also, key horticulture basics:

• Reduce erosion and control weeds -- use mulch over bare soil areas
• Use organic fertilizers, and eliminate the use of pesticides!  The water that migrates off your landscape takes trace elements of whatever you have applied with it!

Where to Purchase Irrigation Hardware

When it comes time to purchase irrigation hardware, go to an irrigation supply store not a big box hardware store.  In your area we recommend Ewing Irrigation at 27562 Commerce Center Drive.  Their phone is 951.506.9530.

Delivery Systems • Posted on 02/23/2009 •   Permalink

Many times, seemingly simple questions have answers that span several disciplines (design theory, installation practices, horticulture and soil science issues), and can become burdensome for someone to try to take in all at once.

To facilitate understanding, we group our information in three broad categories: 

System Management — Irrigation scheduling.  Hitting the “moving target” of plant water need as it changes throughout the growing season.

Delivery System — Spray heads, rotors, emitters, etc.  We try to explain the principles behind how they function, and make sense out of the many look-alike products on the market.

Soil Biology — Living soils and horticultural practices play a very significant role in how effective irrigation can be, and the viability of the landscape.  Think of growing roots, not plants!  Healthy roots will ensure a beautiful garden!