Turf Magazine - September, 2011
Fert and Other Fall Turf Tips
What you do now will have a big impact next spring on the lawns you maintain
Are you ready for winter? More to the point, are your customers' lawns ready for this coming winter? Conditions have been tough on lawns in many parts of the U.S. and Canada this season, and many of these lawns will require early fall TLC.
You want your customers to enjoy the sight of uniformly green, weed-free lawns in spring 2012, right? Happy customers tend to remain customers, and customer retention is huge in these ultracompetitive times.
COURTESY OF SPORTS TURF MANAGERS ASSOCIATION.
Fall fertilization, weed control, aerification, reseeding and resodding are the primary cultural practices used to prepare lawns for winter's colder temperatures and shorter days. Be advised, of course, that one size does not fit all in turfgrass management.
For example, some of you maintain warm-season turfgrass, some cool-season turfgrass, and many of you care for both. Warm and cool-season grasses require significantly different management regimens, including preparation for winter. That presents a dilemma for those of you with many different types of turfgrass to maintain.
Why it takes a pro
Complicating the situation even more, individual species of either category require different levels of care. For example, the amount of nitrogen needed to keep Kentucky bluegrass green and healthy is greater than the amount of nitrogen required by fine-leaf fescues. Both species, of course, are commonly found on lawns across the northern half of the U.S.
Another variable that affects your fall turf program is weather. Conditions often differ markedly from year to year, regardless of where you provide services. This summer's heat and dry weather devastated nonirrigated lawns across Texas and in many regions east of the Mississippi. It will take more than fall fertilization and an application of a winter weed control to restore these lawns. In fact, these lawns (or portions of them) may need to be renovated, including reseeding or resodding.
Don't leave the leaves
Then, of course, there are tree leaves, and what to do with them?
The answer is simple: remove them. Property owners realize you can't grow healthy turfgrass under a mat of tree leaves. Turfgrass, like all living plants, needs oxygen to survive. Also, allowing tree leaves to remain on turfgrass may adversely affect the effectiveness of your application of herbicides necessary for winter weed control. Clients appreciate fall leaf pick up as part of your fall property services, and they'll pay for it.
These are all reasons why homeowners are often overwhelmed when attempting to keep the turfgrass on their properties healthy and attractive. If they're serious about having fine turf, most property owners will eventually turn to a professional like you who understands the challenges of turfgrass management and how to deal with them.
OK, let's get to some general information about preparing turfgrass for winter. Consider it the starting point from which to fine-tune your late-summer and autumn fertilization and weed-control programs.
Stimulate cool-season grasses
This summer's heat and dry conditions caused cool-season turf to thin in many regions of the country. Your task, starting now, is to provide the nutrients necessary to revive the turfgrass. As summer wanes, cooler temperatures arrive, lawns get more moisture, and the grass will start to grow again. Continue mowing - you don't want growth to get out of hand requiring you to bag clippings.
Eventually, of course, falling temperatures and shorter daylight hours will significantly slow plant growth. Research has shown that shoot growth of Kentucky bluegrass slows dramatically as the soil temperature approaches 55 degrees Fahrenheit, but roots continue growing to 40 degrees. As roots continue to grow, they take up nutrients to aid in the production of stored carbohydrates, the energy source that helps turfgrass survive the winter and green up and thicken in the spring.
Many turf pros make two fertilizer applications to prepare turfgrass for winter. They schedule one in late August or September to aid in recovery from drought and heat stress, and another in October or November.
Fertilizing turfgrass in the late fall keeps it greener than unfertilized turfgrass during the winter, and speeds spring green-up by two to six weeks. The enhanced rate of spring greening occurs without stimulating excessive shoot growth, in fact, far short of what takes place with early spring fertilization.
Keep soil moist
Lawn care companies typically turn to nitrogen sources that aren't dependent upon microbial activity to effect nitrogen release - urea, sulfur-coated urea, IDBU and ammonium sulfate, for example. Some companies feel that delivering half the nitrogen source in a slow-release form guarantees that some nutrients remain available for a longer period in the soil for plant uptake.
Regardless, turfgrass requires moisture in the fall, first, to release the nitrogen for plant uptake and, second, to keep the plant growing and healthy as it heads into winter.
The timing of these applications depends largely on geography and climate. The further north you are, the earlier in the season you need to apply fertilizers and herbicides before the ground freezes. It's not advisable to apply products on frozen ground, which increases the likelihood of chemical runoff. Besides, it's unlikely plants will be able to take up the products. Check with you local extension service. It will advise you on optimum dates to make applications in your part of the country.
(Note: In December 2010, New Jersey enacted a law aimed at lessening pollution in its waterways that bans homeowners from applying lawn fertilizers from November 15 to March 1, but allows certified professionals to make applications from March 1 to December 1.)
The amount and timing of fertilizer applications depends on the region where the warm-season grass (St. Augustine, centipede, zoysia or bermudagrass) is growing. If it's in a region where it stays green through the winter, an early fall boost of fertilizer will cause the grass to continue growing and thicken. But, don't overdo it, especially on sandy soils where there's risk of leaching.
In areas were warm-season lawns are regularly subjected to freezing temperatures and go dormant during winter, be even stingier with the nitrogen, and opt for a fertilizer that contains lower ratios of nitrogen to potassium. Potassium is generally believed to promote winter hardiness and disease resistance in turf. You want the turfgrass to continue growing, but not excessively.
Some experts say that if you can only fertilize cool-season turfgrass once a year, fall is the time to do it. Warm-season turfgrasses, which grow best in the summer sunshine and heat, generally do best when fertilized soon after spring greening.
The wider view
To that point, look at your turfgrass fertilization program in the context of your overall turfgrass management program.
Do you conduct or offer soil testing to determine the nutrient needs of lawns under your care? How intensively managed are the properties under your care? How many are irrigated? Almost certainly some require more maintenance than others. And some may require more remedial care, such as aerification or renovation, this fall than others.
Do you mow and maintain these properties? How about leaf removal? These services will have a bearing on how you approach these lawns in terms of chemical services and especially fertilization.
Are the clippings left on the properties that you service bagged and removed? In addition to avoiding the considerable expense of bagging and removing turfgrass clippings, leaving them where they lay after mowing returns nitrogen to the soil.
All of these factors, along with fall fertilization and weed control, enter into the larger challenge of providing your customers a beautiful, green carpet of soft turfgrass from season to season and, hopefully, year to year.
Ron Hall is editor-in-chief of Turf magazine.