September Lawn Care

By John Wilson, Extension Educator

Last week we flipped the calendar over to a new month, and September can be the most important month to get your bluegrass and tall fescue lawns back in good condition after the stressful months this summer, although this year wasn’t as bad as many. I had to mow my lawn every four to five days in August which is unheard of. Normally it’s about every eight to 10 days! I guess Mother Nature thought I could use the exercise.

There are some lawns with brown patches from disease problems this summer. Some of those will fill in as temperatures cool in September, but if they don’t, rake up as much dead plant material as you can, then overseed thin areas by mid-September to give new grass a chance to germinate and get established this fall. Remember to keep the top inch of soil moist, but not too wet, after seeding or overseeding if you don’t get timely rains. One nice thing about seeding in the fall is you generally won’t have the weed competition you do when seeding or overseeding in the spring.

If you haven’t fertilized yet this fall, apply about 3/4 to 1 pound of actual nitrogen per 1000 square feet of turf now, and apply a similar amount toward the end of October. That last fertilization in late October is the most important one you make all year so don’t forget to do that about Halloween-time. This will also give you a slower, more uniform green-up next spring rather than the fast flush of growth you get if you fertilize too early. Avoiding the rapid flush of growth in the spring can also reduce the chance of disease and drought injury later in the growing season.

If you have a thatch buildup, over ½ inch of thatch, power rake your lawn by mid-September. This will give the turf a chance to recover after this operation. Rake up and compost or dispose of the dead plant material after power raking. If the thatch in your lawn is not that thick, consider core aerating rather than power raking. It isn’t as hard on the turf and will improve root growth and water infiltration.

If you have problems with perennial broadleaf weeds such as dandelions, ground ivy or white clover, mid-September to mid-October are the best times to apply broadleaf weed killers. The plants are busy making food and sending it to the roots for next year’s growth. Herbicides applied then will also be translocated to the weed roots, giving you better control. If you wait until after a light frost, you can also reduce the potential for injury to ornamental plants.

If you had your mowing height raised for the summer, leave it at this height this fall rather than lowering it as was once recommended. As lawns start to grow faster in the fall, remember to mow more frequently so you don’t remove more than 1/3 of the total height of the grass. Removing more than that with one cutting will cause unnecessary stress on the turf.

As leaves start to fall, don’t let these accumulate because they can smother areas of grass if allowed to become too deep… especially if you get some rain that packs them down. Mow your lawn and mulch in the leaves before they become too deep. If you luck out and the wind is from the right direction, the leaves may blow off your lawn and onto your neighbor’s lawn… reducing the amount of mowing or raking you’ll need to do.

Besides fertilizing your lawns one last time in late October, the other thing you need to remember is to water your lawn well later this fall, but before the ground freezes, if you don’t get timely rains. This will help your turf go into the winter in a healthier condition and reduce the chance of winterkill.

Following these steps can help your lawns recover from the stress of summer, go into winter in a healthy condition, and reduce problems next year. For more information on fall lawn care, contact your local Nebraska Extension office.