Sam Bauer, Extension Turfgrass Educator
There's no question that the fall drought has taken a major toll on many of the turfed landscapes in Minnesota. If you failed to maintain turf health through supplemental watering from August to October, you most likely have yet to make a damage assessment of your lawn. During the summer months we talk a lot about letting our lawns go dormant during a drought and waiting for rain to replenish soil moisture. This is nothing new. However, the duration of the fall drought has pushed our lawns to the limit, probably passed the limit in many cases. There are two main concerns: 1) how long can turf stay alive in a dormant state?, 2) will drought stressed turf properly harden off and survive the winter?
How long can turf stay alive in a dormant state?
There are no clear answers to this question and it really depends on many factors, including: turf species, traffic, management practices, and site conditions. We commonly hear that Kentucky bluegrass can survive for up to 2 months under drought dormancy, but there is no definite time frame due to all of the variables. From my experience, as long as the crown of the turf did not completely dry out, it should still be alive. I've been encouraging home owners to utilize the last part of the growing season (October) by watering to bring the lawn out of drought dormancy before winter. If you've done this, you should have a good idea just how bad the damage is.
Will a drought stressed lawn survive the winter?
Probably not, and chances are that it may be dead already if you didn't provide at least some supplemental watering to keep the crown from drying out. Turf species will play a very important role here. Perennial ryegrass will be the least tolerant of drought conditions and cold temperatures. You can check to see if your lawn is alive by taking a small sample indoors. Water it and place it on a window sill. You should see some growth in two weeks time.
Last chores of the season
By now you should have completed your last watering, mowing, and fertilization of the season. If you did not keep up with watering this fall and fear the worst, dormant seeding in mid-November will be a great option. For that I would like to direct you to a couple of links. The first link is a great discussion previously published in the Yard and Garden News by Bob Mugaas, retired Extension Turfgrass Educator. Bob discusses the most important factors for dormant seeding, including: choosing the right seed, seed to soil contact, and post seeding management. The second link is from the Virtual Field Day that we held this fall. In it, Dr. Eric Watkins professor of Turfgrass Breeding and Genetics discusses your turfgrass species options for Minnesota lawns. I encourage you to consider all of the species characteristics when choosing the turf seed for your lawn.
On the horizon: In search of a more sustainable grass
These are exciting times for sustainable lawn care in Minnesota. A $2.1 million dollar USDA grant was recently awarded to the University of Minnesota's Turfgrass Program for the improvement of fine fescues. Dr. Eric Watkins, a professor at the University of Minnesota, is the principle investigator on this project, which is a collaboration with Rutgers University and the University of Wisconsin-Madison. Intentions for this research include changing consumer habits, as well as improving the genetics of these low maintenance species. Please follow the links below for more information: