Lawn dying

Question: My backyard has been dying over the last few years. I water 3 times a week but it still is dying off and spreading. Could this be a pest? How do I test for this? I would like to xeriscape part of it and replant the other part. If there is a bug I need to treat for it first

responder: Joan N.  Replied June 05, 2023, 4:14 PM EDT
response: Dear Peter, I received your inquiry about your lawn. Before I can proceed, I would need a little bit more information.  I can see in the photo that one part of the area has green grass and the other not.  Have you taken a good look at your irrigation system to see if all of the sprinkler heads are reaching every area? What time of day do you water and for how long? Is the poor area facing NSE or W? Do you have pets that urinate in the area? There seems to be several colors - can you tell me if there is a ground cover weed growing there? And if so, could you provide a good close-up photo of the leaves? A few more photos of the yard might be helpful. Has there been anything spilled or sprayed there? Do you use winter de-icing material that might get pushed off into this area with the snow? Can you easily push a screwdriver into the soil in this area? Have you ever had your soil tested for percent organic matter and other soil properties? If so, how long ago? Once I receive your answers, I'll do some more sleuthing! Sincerely,

responder: The Question Asker Replied June 10, 2023, 10:15 AM EDT
response: Thanks so much for the help. Some background - we have lived here over 20 years and this area has always had problems. I removed grass and terraced over time try to help.  Answers to your questions - The sprinkler system is not perfect. I have at least one head that needs to be raised. I can do the container test to really test it. However this problem seems to be spreading on its own regardless of how much I waterWe water 3 days a week for 20 minutes in the early morning. If I water more I have been able to get improvement but at this point the weeds improve too.The area faces South, Southeast. It gets a lot of light all dayNo pets for 5 years nowThere is a weed patch that is red - spurge? Last year I cleared this area and tried to seed but the weeds took overI will provide more pictures nextThere has been nothing sprayed or spilled there. There is no deicer used in this areaI have not had the soil tested but I have been thinking that might be a good idea. I will try the screwdriver test when I go out to take more pictures

responder: The Question Asker Replied June 10, 2023, 10:34 AM EDT
response: Here are some more pictures. The screwdriver test seemed ok although the lower you go the more dense the soil. In general we are at the foot of a mountain and the soil is very rocky. My main concern is how to recover this area. We want to xeriscape a large part of this but leave some grass.

responder: The Question Asker Replied June 10, 2023, 10:38 AM EDT
response: more pics...

responder: The Question Asker Replied June 10, 2023, 10:40 AM EDT
response: more...

responder: The Question Asker Replied June 10, 2023, 10:41 AM EDT
response: more....

responder: Joan N.  Replied June 15, 2023, 1:25 PM EDT
response: Dear Peter, Thanks for the photos and for answering the questions. I think you have several things going on. However, despite what we can or cannot identify, the recommendation  will probably be the same. First of all, a nice thick lawn is the best prevention of weeds because the turf does not allow the weed seeds to touch the soil. You could still get weeds like bind weed coming up through the turf, but in that case, persistent pulling of that weed would be necessary. Second, if the irrigation system is faulty, or if it is not set to water the proper amount needed, the grass will begin to decline, or at least decline in the areas that are not getting what's needed. So the irrigation system must be set to supply the proper amount in the right areas. Without the ability to actually be there to look closely, I believe that you have a weedy grass that has seeded into the area where you have the  dead golden-colored area.  The area with the heavy covering of purslane proves the ability of weeds to take over bare soil. There are numerous types of weeds in the area that have dropped seeds over time. Even so, the decision of what to do next if you want turf grass in the area is to prepare the area for a new lawn -- either seed or sod. You will want to kill what is existing with glyphosate according to the label, then approach the situation with a plan to create what would be pleasing to you. We have many fact sheets on how to create a healthy turf environment, as well as how to reduce the turf and create a pleasing landscape that might require less water, while still including plants. Depending on what you're interested in, you can reply and I can forward information to you.  You can also use Google or another web browser to search: 'topic' site:colostate.edu. this will take you to research-based information at Colorado State University Extension. The outcome you want to achieve will take planning, time, energy and money, of course, but in the end, I hope you are pleased with the results. Sincerely,

responder: The Question Asker Replied June 17, 2023, 10:12 AM EDT
response: Thank you for taking a look. I agree much of the lawn is dead and needs to be redone. My main concern was some kind of pest that would ruin the new lawn. I don't think that is the case now and will proceed. We plan to cut the size of the old lawn roughly in half and redo the sprinklers. I think in the end the sprinklers may be the real culprit but it took years to go bad. It was an accident in slow motion I guess. One question on removing the old stuff - is it better to use a herbicide or is it better to use a rototiller or a sod-cutter ?

responder: The Question Asker Replied June 17, 2023, 10:36 AM EDT
response: While I have your attention, we plan to plant a tree in the area we will be mulching. We have been looking at native species but so not want a conifer. That leaves cottonwood, aspen, and I don't know what else. Is there a native deciduous tree you would recommend? At this point I am thinking a locus tree for drought tolerance. Any ideas?

responder: Joan N.  Replied June 19, 2023, 8:38 AM EDT
response: Good morning! I have a list of native trees researched by the Colorado Master Gardeners in El Paso County.  It lists six native trees that are not conifers and does not include aspen or cottonwood. I hope this will help you find what you are looking for. Be sure to plant it properly. Here is some information from Colorado State University to help you with that.  Best of luck!