(Editor's Note: This article was originally published on September 19, 2008. Your comments are welcome, but please be aware that authors of previously published articles may not be able to promptly respond to new questions or comments.)
As white walls are to musem paintings, so a green lawn is to your perennial beds. Although many gardeners treat the lawn as just something to comfort the bare feet of summer, a nice lawn is also the backdrop that makes your flowerbeds "pop." Some maintenance this fall will go a long way towards getting your cool-season lawn in good shape for spring. Before you start spending the big bucks, refresh yourself on the basics of fall lawn care.
Fertilizer- How much and what kind?
Your fescue/bluegrass blend lawn needs energy (fertilizer) in the fall. These cool-season grasses are coming out of summer dormancy and are ready and willing to grow in the cooler weather of autumn. At the same time, the soil has used up the natural pool of nitrogen that it was drawing from in spring and early summer. Before you go to the garden center, though, you need to estimate the area you'll be covering, in square feet. Try this table:
Size of your lot
Area in square feet
Now you're off to the garden center to buy a bag or two of turf fertilizer. It's usually sold in smaller bags to treat about 5,000 square feet, or larger ones that cover 15,000 square feet. Be sure you're buying something labeled for lawns. Most are made to deliver what your grass can reasonably use when you follow the label directions. The best kind for fall will say winterizer and slow-release nitrogen on the label. Don't get starter lawn fertilizer unless you are putting down seed.
Find the "analysis" somewhere on the bag to be sure you have the right kind of fertilizer--
High (Nitrogen)-- Low (Phosphorus)--Medium (Potassium)
Fertilizer- conventional or organic?
Conventional- Standard, name brand fertilizers, unless specified otherwise, are conventional (chemical-based). They cost about ten to fifteen dollars per 5,000 square foot application. Conventional fertilizers are economical and can be designed for slow release, though not all are. Weed killer can be included in a conventional fertilizer (see weed killer section below).
Organic fertilizers- Organic (or all natural) fertilizers will be prominently labeled organic or natural. They cost more than conventional; spend around twenty dollars and up for the same size application. All are slow-release and made by blending materials from plant or animal origin with minerals. Double check the bag application size- these can be bulkier and a big bag may cover only as much area as a smaller bag of conventional fertilizer.
Fertilizer - when and how to spread it
One treatment of quality, slow-release fertilizer in September is a reliable recommendation. If you have the time, and really want to boost your grass growth, wait at least a month and make another application. If you can't get to the lawn treatment until Thanksgiving, do it then but no later.
A broadcast spreader gives good overall coverage of the lawn. Use a low (light) setting and make more than one pass. Move the spreader to the sidewalk or driveway while filling it, and sweep up any spilled fertilizer so you can toss it back in the spreader. Water the lawn after you've fertilized.Herbicides (weed killers)
The weeds that grew over the summer have already set seed and will die or go dormant in winter. If you have too many weeds to ignore, you can use "broadleaf weed" herbicides in early September to kill warm weather weeds while they're still actively growing. All broadleaf weed killers are chemical. Expect to spend around twenty dollars per 5,000 square feet of coverage. Pre-emergent herbicides are used, in late fall, to prevent weeds like chickweed that sprout over the winter and make a big show in early spring. If crabgrass is your biggest weed problem, do not use pre-emergent herbicide now--wait until early spring.
As with fertilizer, you can choose either a chemical or an organic pre-emergent herbicide. A 5,000 square foot application of chemical pre-emergent is running about ten dollars, the same size treatment of organic pre-emergent is priced at just over a hundred dollars here. Good to note, though, is that organic (corn gluten meal) pre-emergent gives a good nitrogen dose. Herbicides should be used only if really needed, and extra attention to the lawn now will beef up the turfgrass and prevent those weeds from dominating. Follow label directions on herbicides.
pH adjustment (lime)
Lime is used to make an acid soil more alkaline, which helps plants use nutrients effectively. Lime is cheap, but why waste money? Don't add lime unless you have had a soil test and know that you need to. If you need lime, use the recommendation from your soil test, and water it in with the fertilizer.
Insecticides and grub control
Bags of bug killers may well be lying around at the garden center, but this is not the right time of year to use them. Don't buy any.
Again, these may be in stock at the store, but turf fungus is a minimal concern in fall. Skip the fungicides.
You've been mowing your lawn all spring and summer with the mower height at 2½ to 3 inches. (Haven't you?) Keep it there. And you leave your clippings on the lawn, because that recycles nutrients and adds to the soil structure. Keep mowing as the grass needs it. When leaves start to fall, you can mow-mulch those too. A light scattering of leaves will chop up nicely and disappear. When the leaves come down fast, put the bagger back on the mower and pick up those clippings. They make a great compost starter, a layer in a new lasagne bed, or a fluffy mulch in planted areas. Between mowings, don't let tree leaves lay on the lawn too long, especially when you've had rain. A patch of wet leaves will quickly smother the turfgrass. That leaves a hole for weeds to sprout.
Water right after applying lawn treatments, but then irrigate only as needed. The turf won't need as much addded water as it did over the summer. On the other hand, if the weather is dry, set up the sprinkler so the grass can soak up what you have put down.
Adding organic material
A thin layer of homegrown or commercial compost, one-quarter to one-half inch in depth, could be spread over and raked into the lawn. This adds slow-release nitrogen, organic matter for good soil texture, and microorganisms for soil health. A bag of compost from the garden center will be pretty cheap at about five bucks but will only cover about a five-foot by five-foot area.Soil testing
I haven't yet mentioned soil testing. It's my guess that you already know you should test, but really want to get the lawn treatments done right now, today if possible, and just won't wait for test results. This article is meant to give you good reasonable guidelines for fall lawn treatments. However, lots of factors affect how much fertilizer and other treatments your lawn will want. A soil test tells you more precisely what your grass needs. It also may tell you what you DON'T need to buy, and that could save you a few greenbacks. Fall is probably a less busy time of year for the state labs than spring. If you want more details about soil testing, read the very informative "Don't Guess, Soil Test" by Paul Rodman or the equally instructive "Understanding Soil Testing" by Darius Van d'Rhys.
This is a beginner's guide to doing your own basic lawn maintenance in the fall. I have tried to present guidelines for those lawn tasks which are recommended for the average homeowner. Turf grass maintenance can be much more involved than this; many people devote their entire careers to turf science. The state university nearest to where you live most likely has plenty of helpful publications that will explain lawn care in more detail. Several of them are linked below in the reference section.
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Endnotes and references
 Goatley, Michael Jr. and Shawn Askew, Fall Lawn Care, Virginia Polytechnic Institute and State University
 Robson, David, Fall Lawn Care Guide, University of Illinois
 Northeastern Integrated Pest Mangement Center and North Central Integrated Pest Management Center, Growing Green Lawns,
 Kowalski, Thomas, Late Summer and Fall Lawn Care, Cornell University
 McDonald, David K., Ecologically Sound Lawn Care for the Pacific Northwest, Seattle Public Utilities
Here's a link to a University of Maryland publication discussing soil testing which includes a list of regional soil testing labs in the Northeast/ Mid-Atlantic area.