Q. I have some problems with my lawn and I sent you some pictures. I am a recent transplant here from Chicago and I am not sure how to manage this lawn and get it flush, green and thicker. The lawn has bare spots and the tree in the center of the lawn has roots on the surface of the soil. How should I repair this lawn? How do you manage a lawn here? Is this lawn savable? Was the tree planted too shallow? What is this green net in the lawn I found? I remember you said to apply fertilizer to a lawn around Thanksgiving. But during that time it was cold and the fertilizer bag says to water frequently.
From the look of the lawn it appears to be tall fescue. Make sure the irrigation sprinklers, pop-ups, rise 4 inches above the lawn. Some pop-up sprinklers are 2 inch, 3 inch and 4 inch. With tall fescue it is important that these are 4 inch since the lawn will be mowed at 2 inches or higher. 2 inch pop-ups are not adequate and you must replace them with 4 inch pop-ups. The pop-ups operate on a spring. You have to pull will pop up with your hands to measure the height or turn the irrigation system on.
Head to head coverage |
Next, when the irrigation system is on the water from one sprinkler should be thrown all the way to a neighboring sprinkler to get head to head coverage. 100% coverage or head-to-head is very important for sprinkler system to operate efficiently in the desert. Thirdly, when the sprinkler system is operating you should see droplets coming from the sprinkler and it should not be fogging or misting. If you see fogging or misting the from the sprinklers this is an indication that the pressure of the system is most likely too high.
Pressure regulator |
A pressure regulator would then be installed on your irrigation system to lower the pressure within the manufacturer’s suggested operating pressure which is usually somewhere around 40 or 45 PSI. Or you can replace the nozzles of the sprinkler pop-ups with pressure regulated nozzles. This may be a less expensive option for you since the nozzles are relatively inexpensive. The nozzle unscrews from the top of the pop-up. If the pressure of your system is 60 or 70 PSI you will definitely see some fogging if these are the older type nozzles. You should make sure that the nozzles are matched. This means that they all come from the same manufacturer with the same specifications or model.
Small triangular piece of lawn in upper right that makes the lawn difficult to irrigate without water running into the street, over watering the lawn or under watering the small triangular piece |
Depressions in lawn around sprinkler due to a line trimmer instead of replacing the two inch popup with a four inch popup |
It is also possible if the tree creates a lot of dense shade underneath it that the lawn will begin to thin due to a lack of light. In this case, the usual recommendation is to begin to remove lower limbs and thin the canopy of the tree to admit more light for the lawn. An option you might consider if you want the lawn to remain is to remove the tree. Another option if you want the tree to remain, is to remove the lawn and revert the landscape to a desert themed landscape.
Plastic netting on a roll of tall fescue sod. |
General maintenance of a tall fescue lawn would be fertilizing on Labor Day, Memorial Day, Fourth of July and Thanksgiving. If you are mowing with a mulching mower and returning the clippings back to the lawn and then you can skip your Fourth of July application. The fertilizer that you use should be high in nitrogen, low in phosphorus and moderate in potassium. These represent the three numbers on the fertilizer bag. If you were to make a ratio of these numbers by taking the lowest number and dividing it into the other two the ratio should be 3:1:2 or 4:1:2. Examples might be 21-7-14; 15-5-10; 20-5-10, etc. These numbers do not have to be precise but they should generally be in those ratios.