Irrigation Check - Gardeners Tip

Annual Spring

Quick - Irrigation Check

Bulletin #TP1052

Horticultural Observations
for Healthier Landscapes

There are some things you should check into in order to make sure your plants do well this summer.

◊ Frost Damaged Plants

◊ Walk Your Landscape

◊ What to be looking for

◊ Measure Emitter Flow Rates

◊ A few commonly used drip emitters

◊ Each plant needs enough water

◊ How Many Emitters does a plant need?

◊ Warm weather planting

Frost Damaged Plants

If you have some plants that struggled this past winter from frost damage, keep you eye on them. The cold may have weakened the plants and now they need to survive some high temps. If you successfully coddled them along through the spring, bringing them back from the brink, you surely don't want to lose them now. An irrigation check should definitely be done for all these plants. Resist the temptation to over-water them when it gets hot. Keeping the soil overly wet doesn't help them at all. In fact it can be the very thing that pushes them over the edge. If one of your recovering plants begins to show excessive heat symptoms cover it with some nylon screening. Don't do summer pruning.

Walk Your Landscape

Take a walk through your landscape with a notepad and pen. Jot down any plant that looks like it may need some irrigation attention. Avoid the temptation to make repairs on the spot as you may never finish the inspection. If you plan to do an evening inspection, when the temps are nicer, make sure you have new batteries for that flashlight.
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What to be looking for

First look for emitters that don't work or are partially plugged. Emitters that are adjustable and not putting out much water are also on the list. You need to know how much water is supposed to come out of an emitter in order to know if it is performing well.

Measure Emitter Flow Rates

Run Time	Runs per day	Desired gallons	Time for 1 Tbs
5 mins.	3	1/2	7 seconds
10 mins.	3	1/2	14 seconds
60 mins.	1	1/2	28 seconds
5 mins.	3	1	3.5 seconds
10 mins.	3	1	7 seconds
60 mins.	1	1	14 seconds
100 mins.	1	1	23 seconds

Use a measuring tablespoon, and time how long till your measure fills.

Here is a good rule of thumb; each emitter should put out a minimum of ½ gallon of water on a watering day. Most should put out between 1 and 2 gallons.

If it takes longer than the listed time to fill the measuring spoon, the plant is not getting deep water.

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As you can see, if it takes 14 seconds to get a tablespoon the rate is 1gph so, a 7 second fill would indicate 2gph, etc. Three times during the day for 20 minutes each is the equivalent of 60 minutes.

A few of the more commonly used drip emitters

Pressure Compensated 0.5 to 1.0 gph autonomous	Pressure Compensated 0.5 to 2.0 gph autonomous
Non Compensated 1.0 to 4.0 gph autonomous	Adjustable 3.0 to 15.0 gph autonomous
¼" Slow Rate Dripperline 0.5 to 0.65 gph in-line	½" Slow Rate Dripperline 0.9 to 1.0 gph in-line

Flow rating information imprinted on the emitter is generally specified in "liters" not gallons, so you would divide by 4 to get an approximate gallon equivalent.

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Each plant needs enough water

Once you know how much water your emitters are putting out, you have a good chance of preventing your plants from dying of drought. Insufficient water equals shallow water, and subsequent shallow roots and summer stress. Desert type drought tolerant plants can survive on ½ gallon per emitter location, while more traditional plants will require from 1 to 2 gallons (depending on soil and amount of sun). If your results show that you not getting this, come into Star Nursery and talk with our irrigation people. There can be a number of reasons for the problem, from too many emitters causing low pressure, to a plugged emitter.
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How Many Emitters does a plant need?

The next issue to inspect is for an adequate number of emitters per plant. Again with a rule of thumb; Clay-type soils will typically have a spread of 2-4 sq. ft. (with a 1 gallon application) for each emitter. A traditional shrub, three feet in height and width would generally do well with 9 sq. ft. of watered root system. Many similarly sized desert shrubs could tolerate a root system 60% that size. Larger shrubs need larger root systems in order to tolerate our summers. If you have enough emitters putting out deep enough water, and you didn't forget to feed them, chances are that you plants will do well.

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Warm weather Planting

Now that we have our irrigation up to speed, are there some new plants we’d like to add? If so, what can we plant now that the heat is with us? First, know where you intend to plant. Is the location afternoon sun or morning sun? With afternoon shade you still have many choices that will do just fine. Use caution if the spot is blazing hot in the afternoon. Most desert type plants will tolerate being planted in these areas during the summer, but not too many traditional plants will. For tropical summer color, check out the Yellow Bells and Honeysuckles; they love the heat!

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