Lawn restoration

Question: Our lawn has several problems- patch spots, moss and rings. I’ve included photos and would like to know how to correct these. We do have a lawn care company. For the last three seasons they have applied four weed and feed applications May-Sept. They are expensive and unfortunately the problem areas just seem to get worse. Not better.

responder: Steve Miles  Master Gardener, Hennepin County MN (I answer using human intelligence, not AI)  Replied June 05, 2024, 10:33 AM EDT
response: Thank you for writing. The second picture, looks like nitrogen burn. The hall mark is the dark green grass with a place where the grass looks dried up.  https://extension.umd.edu/resource/fertilizer-injury-lawns/ Here are some tips on repair. https://blog.davey.com/grass-turning-yellow-after-fertilizing-here-s-how-to-repair/  Grass does not need this much care. All weed killers are at least somewhat toxic to grass.  Unless you have a nutrient problem as indicated by a soil test, it is extremely unlikely you need four applications per year.  In fact, applying fertilizer in mid summer is a particular problem because the grass is not growing as much in the heat.   Set the mower height to 4-4.5 inches. Stop further applications by the lawn service. Get a soil test and write back to me. https://soiltest.cfans.umn.edu/testing-services/lawn-garden

responder: The Question Asker Replied June 05, 2024, 2:29 PM EDT
response: Thanks for your prompt reply. I will speak with the person who is applying weed and feed about the nitrogen burn. And maybe just contract for the fall. What about the moss that is replacing grass in a lot of areas? I sent a photo in the first email. Also is the patchy area nitrogen burn too? Someone passing by said it could be grubs. One further question. We have an irrigation system. A lawn care service here said to water at night every other day for 20 minutes at each zone. We have 9 zones which means the pump runs from 11:00 pm  till 2:00 am (3 hours). On the UofM site I read that it’s better to water less often and a   Longer cycle. What do you think?From Barbs I-phone On Jun 5, 2024, at 9:33 AM, Ask Extension <<personal data hidden>> wrote:﻿

responder: Steve Miles  Master Gardener, Hennepin County MN (I answer using human intelligence, not AI)  Replied June 05, 2024, 3:36 PM EDT
response: Thank you for writing back. You are watering far too much. Put a rain gauge ($3 at hardware stores) out to measure your zones according to U guidelines.  https://extension.umn.edu/how/water-wisely-start-your-own-backyard#:~:text=If%20watering%20is%20required%2C%20it,minus%20any%20rainfall)%20per%20week. Moss loves wet environment. The other problem with this much water is that the grass roots stay on the surface rather than diving for water.  This results in a looser sod structure which is welcoming for weeds.

responder: Steve Miles  Master Gardener, Hennepin County MN (I answer using human intelligence, not AI)  Replied June 05, 2024, 3:41 PM EDT
response: Thank you for writing back. You are watering far too much. Put a rain gauge ($3 at hardware stores) out to measure your zones according to U guidelines.  https://extension.umn.edu/how/water-wisely-start-your-own-backyard#:~:text=If%20watering%20is%20required%2C%20it,minus%20any%20rainfall)%20per%20week. Moss loves wet environment. The other problem with this much water is that the grass roots stay on the surface rather than diving for water.  This results in a looser sod structure which is welcoming for weeds.

responder: The Question Asker Replied June 05, 2024, 9:07 PM EDT
response: Great reply! Thanks for your advice and I feel like we are on a path to a healthier lawn.From Barbs I-phone On Jun 5, 2024, at 2:41 PM, Ask Extension <<personal data hidden>> wrote:﻿

responder: Steve Miles  Master Gardener, Hennepin County MN (I answer using human intelligence, not AI)  Replied June 05, 2024, 10:48 PM EDT
response: Get the soil test.  You are going to have to live with your lawn this summer.   Then it will have to be renovated. https://extension.umn.edu/lawn-care/renovating-lawn-quality-and-sustainability In late August or mid September it is going to need to be reseeded with 60% fescues.  No more herbicides.  Mow high.  Send me the soil test results.