I was just reading another article about fall lawn care from the University of Minnesota Extension and they suggest renovating your lawn if you have between 20 and 40% weeds.
Well, considering my “lawn”, and I use the term loosely, is likely closer to 60 to 70% weeds, I may have to take heed. Granted, this has, once again, been a tough year on turf. Most of us had crisp lawns but we just recently had an inch and a half of rain. Will that be enough? No, likely not. If you want to save your lawn, you need to water it.
You can aerate after your lawn’s health has been restored. The U of M extension says don’t dethatch or use a vertical mower if your lawn is not healthy. This process tears turfgrass leaves and crowns, and should only be conducted when the lawn is healthy. Of course, don’t spray herbicides on a brown lawn. Systemic and contact herbicides used for weed control are more effective when weeds are actively growing. Choose fertilizer sources with at least half of the nitrogen component present in the slow release form. High rates of quick release nitrogen fertilizers can have negative effects on drought-stressed turf. There is also a greater potential for environmental loss of nitrogen when the lawn is not actively growing.
Raise the mowing height and mow less frequently to encourage turfgrass recovery. You can spot seed and fertilize thin, weak areas with a high-quality turfgrass seed mixture. It’s best to buy seed from your local nursery and ask them what they recommend for your sun/shade conditions and the type of traffic that’s normally on your lawn.
Of course, performing a soil test to determine fertilizer requirements of phosphorus and potassium is always a good idea. You can use a kit from a nursery or mail a sample into the U of M. I’ll have links and also more information on my website, Garden Bite. For further information, click on this link to the University of Minnesota Extension website called "Lawn Renovation". Be sure to check out videos from this year's season of Dig In Minnesota.