Thursday, October 28, 2010

Are your sprinkler system valve boxes too deep?

They should be even with the surface of the ground so you don’t fall in the hole or have problems when mowing.

If your valve boxes are like the one shown in this photo, you should consider correcting the problem before you fall into the hole and break a leg. Valve boxes that are too deep will eventually be covered up with soil and sod making it difficult to find the irrigation valves when you have a problem with those zones.

The valve box can be dug up and reset at ground level. When you do this the valve will still be at the same depth in the ground. Raising the box usually allows soil to seep into the box and cover the valve. If the valve box is only an inch too deep, raising the box should not cause too much of a problem later on as long as the valve is still protected inside the box.

When you have to raise the box more than an inch, soil and other debris will most likely filter under the box and cover up the valve(s) from the sides. This can create problems with the operation of the valve(s) and will hamper any repairs that need to be done later.

Valve boxes are designed with cutouts at the bottom. These are the areas where the pipe enters and exits the box. When these cutouts are removed and the the box placed over the pipe, the valve will be properly protected and placed above the soil at the base of the box. Putting a layer of gravel in the bottom of the box helps keep soil from filter under the sides of the valve box.

Three and six inch extensions are available for valve boxes for your local box store, hardware store and irrigation supply company. This photo  shows a three inch extension placed on a standard size valve box. The item on the left of the photo is a 6 inch extension for a jumbo size valve box.  The lid fits into the recessed area of the extension.

Instead of raising the box, consider placing an extension on top of the box. You may need to dig up the box and set it deeper in order to do that. Be sure the valve box is parallel with the slope of the soil.

The more secure the irrigation valve(s) are ensconced inside the valve box the better. Valves that are covered with mud and other debris are problems waiting to happen.

If you don't feel comfortable correcting valve boxes that are too deep, lawn care, landscape or irrigation installation professionals can do this for you.

Monday, October 25, 2010

Harvest your apples before the temperature drops below 30 degrees F.

Cold temperature injury of apples results in the formation of ice crystals in the spaces between the cells.  When this occurs the cells may die.  A common symptom of freeze damage is seen in the photo below.  This photo is courtesy of Washington State University.

The temperature at which apples suffer freeze damage ranges from 27.3 to 29.4 F depending on variety for an average of 28.4 F. I would suggest apples be harvested and stored in a frost proof area if the temperature is forecast to go below 30 degrees F. 

If you are unable to pick the fruit when temperatures below 30 F. are forecast, as may occur with later ripening varieties, wait until the apples have thawed before harvesting and/or handling.  This will limit the extend of the damage.

Tuesday, October 19, 2010

Misting in Action

Misting of irrigation sprinklers is due to excessive pressure at the nozzles.

 Irrigation nozzles are designed for a specific range of pressures.  Pop-up spray nozzles as are used at the Red Cross facility shown in this video are designed for pressures between 15 to 30 psi depending on spacing.

This video was taken Tuesday morning when the air was still .  You can tell from the lack of movement of the leaves, wind was not responsible for the misting. 

I'm quite sure this Red Cross office in Grand Junction could use help purchasing and installing the needed pressure regulators to correct this problem.  Installing pressure regulators will reduce their utility bills and conserve water that is now going to waste.

There is a specific procedure you need to follow when installing and adjusting the pressure regulator.  Check out Mark Austin's video at for a short demo. Your irrigation professional should have the necessary Schrader valve and be able to install pressure regulators for you if you can't figure this out yourself.  Pressure regulators need to be installed when the system is still pressurized. So do this before you have your system winterized or first thing in the spring when the system is turned back on.
Hunter and Rainbird pressure regulators are adjusted the same way.  Keep in mind you need to buy the pressure regulator that fits the valve.  A Rainbird pressure regulator will not fit a Hunter valve or vice versa.

Sunday, October 17, 2010

Cheatgrass control should be accomplished this fall. Don't wait!

Downy Brome, Bromus tectorum, known as cheatgrass, is a weedy grass that germinates in the fall, goes dormant in the winter, begins growth again in the spring and will complete growth next summer.
The long sharp awns on the seed penetrate the skin and ears of cats, dogs and other animals. When the plant dries the chances for fire is very likely.

This grass is soft and hairy on the upper and lower side of the leaves. When you pull a leaf down and look at the point where the leaf touches the stem, you will see a membrane (the ligule)  that is very thin and hairy or toothed as seen in the photo below.  The  photo is courtesy of

This weedy grass should be sprayed now if at all possible. Glysphosate is a great herbicide with systemic properties killing roots along with leaves and stems.  However, this herbicide is likely to kill plants you don't want killed if the spray gets on those plants. If you use glyphosate, use it carefully.  Safer chemicals to use include fluazifop-P-butyl and sethoxydim. Fluazifop-P-butyl and sethoxydim are also systemic and will kill roots and rhizomes.

Fluazifop-P-butyl sis old as Ornamec 170 and Ornamec Over-The-Top.  These products can be used in and around ground-covers, shrubs and trees  in landscape beds, container yards and grower nursery fields without damaging broadleaf plants.  Over 500 plants are listed on the label over which this product can be sprayed. Other Fluazifop-P-butyl products registered for use in Colorado in 2010 include Green Light Bermudagrass Killer and Ortho's Grass B Gone Garden Grass Killer.

Sethoxydim is effective on annual and perennial grasses to include turfgrasses.  This material is not effective on sedges. Sethoxydim is sold as Bonide Grass Beater Over-the-Top Grass Killer Concentrate (13% sethoxydim), Ferti-lome Over-the-Top II (18%), Hi-Yield Grass Killer Post-emergence Grass Herbicide (18%), and Poast Herbicide (18%). . Not all of these products are labeled for landscaped areas so read the label.   Treatment of reed canarygrass, a major weed along irrigation ditches significantly reduced seeding and biomass production of this grass, especially when the dead grass was mowed down prior to the next year's application of Sethoxydim.

Products used for burn-down only.  These are not systemic and will not kill the roots.

Scythe is a pelargonic acid and similar fatty acid combination that burns back the top of the plant.  Since cheatgrass is an annual, it has no below ground buds from which to recover.  When used on perennial weeds, you can expect the plant to recover from its below ground buds.  There is no systemic activity with Scythe. This product is not approved for organic production.

BurnOut II is a blend of lemon juice, clove oil and citric acid and provides non-selective control of herbaceous broadleaf and grass weeds. This product is a contact kill and has no root activity. BurnOut II is approved for organic production by OMRI.

Weed-Aside, an ammoniated soap of fatty acids, has no root activity and thus does not kill the roots of perennial weeds. It is quite effective on annual weeds such as cheatgrass.  While this is said to be organic, I can not find any agency that has certified Weed-Aside as approved for organic production.

The smaller the grass is when it is sprayed the more effective the treatment.  Don't wait until next summer to try and control cheatgrass.  Treat and kill it now!

Wednesday, October 13, 2010

Change in Job Responsibilities

Greetings from Grand Junction, Colorado

My job responsibilities have been revised and I will now devote 80% of my time to the commercial industry.  20% of my time will be devoted to the Tri River Area Master Gardener Program.

Susan Rose and the Tri River Area Master Gardeners will be handling all homeowner questions. The Master Gardener desk number is 970 244-1836. We have not yet revised Susan's job responsibilities but should have those changes in place by the end of October. 

Questions from the commerical green industry can be addressed to or 970 240-1840.