Preparing for fall lawn care

By Katie Winslow, U of M Extension

The rain over the past week has helped to green up many of the lawns that had gone dormant over our summer heat and drought. As we head into September, it is time to start thinking about our fall lawn care. This year, perhaps more than ever, what you do this fall will have a great impact on the health of your lawn next Spring.

Hopefully, you held off on mowing your lawn while it was dormant. Mowing dormant lawns can result in stress and die-back of the grass. As your lawn comes out of dormancy this fall, greens up, and begins growing, you will need to mow again. Remember that your lawn should be at least 4 inches tall, and green prior to mowing after dormancy. Then you can continue to mow throughout the fall until your grass stops growing.

Early September is the best time of the year to plant grass seed if needed. The grass seed will germinate readily, and the cooler soil will encourage it to develop a good root system that will carry it through the winter. You will need to water the grass seed on a regular basis to ensure germination. Seeding now allows for grass to establish better than in the Spring when grass seed must compete with germinating weed seeds.

If you wish to eliminate weeds, fall is the time to control perennial broad-leafed weeds such as common dandelion, creeping charlie, and plantain. The drought this summer did cause some of these common perennial weeds to die off. Be sure to do a lawn assessment prior to deciding if treatment is needed this year. You may also see weeds that have thrived during the drought but may not return next spring depending on weather conditions. Perennial weeds move the sugars produced in the leaves to underground roots or rhizomes for the winter and to fuel next year’s growth during the fall months. This movement of sugars continues as long as the plants are not killed by frost and 50-75% of their leaves are still green and actively growing. Herbicides that are systemic and move within the plant are carried with the sugars to effectively kill the plants at the root in the fall. Although the death of weeds may not be obvious in the fall, most of them will not come back next spring. Spot spraying or hand-pulling is generally better than covering the entire lawn. Take caution when using chemicals and always read and follow the label.

For an improved lawn in the spring, use the autumn months to take care of seeding and weed control. For a full lawn care calendar, you can visit http://www.extension.umn.edu. If you have questions or would like more information about fall lawn care or any other horticultural questions, please reach out to your local Extension Educator. Residents in Stearns, Benton, and Morrison Counties can call (320) 255-6169 ext. 1 or email wins0115@umn.edu.