It’s that time of year again. The harsh realities of winter will soon recede into memory. As the snow melts, and the cold weather gives way to warmer days, the emergence of spring offers the promise of renewal and hope eternal.
Dormant trees and vegetation go from stark to budding; blossoms give way to newly formed leaves. Lawns that lay dormant from the winter freeze are ready to wake up. For the landscape professional, it’s time to spring into action and help nurture that brown unsightly patch of land in front of a client’s house back into a beautiful thriving lush green lawn.
It almost goes without saying that the key to any thriving lawn is nutrition. That’s why it’s imperative that the first treatment when preparing a lawn’s transition from dormancy contain the right mix of fertilizer and pre-emergent weed control. The fertilizer is essential in supplying the lawn with the food it needs to grow; the pre-emergent herbicide helps stop weeds before they can grow.
Since factors like climate and weather conditions affect when a lawn emerges from its dormant stage, we will be as broad as possible when describing the procedures and timetable for achieving and maintaining a healthy lawn.
The science of soil and plant management (agronomy) is rather complex; to master its principles takes years of study and education. But there are some essential basics that can be universally applied and easily understood. Let’s start with the main ingredients found in most fertilizers.
At least 17 elements are needed for proper plant growth; some like carbon, hydrogen and oxygen are found in air and water, others come from the soil. Nitrogen (N), phosphorous (P) and potassium (K) are the three major nutrients used by a lawn in the greatest quantities. When the soil cannot supply these essential elements, a properly balanced fertilizer can make all the difference between a healthy looking lawn and one that’s on life support.
When choosing a fertilizer, the product information that you need to be most concerned about is the N-P-K analysis. This series of three numbers and letters is a fertilizer’s guaranteed analysis required by the Department of Agriculture, and is prominently displayed on the product label.
Each number represents by weight the percentage of that nutrient found in the fertilizer. For example, if a label states that the analysis is 16-6-8, 16% of the fertilizer is made up of nitrogen, 6% is phosphorous, and 8% is potassium. The balance of the fertilizer is the carrier, which helps deliver the nutrients to the lawn’s root system. These three essential nutrients affect a lawn’s development in different ways.
Nitrogen contributes to a lawn’s growth and helps make it greener.
Too little or too much nitrogen can cause major problems. Not enough will
cause slow growth and a thin turf. Too much can lead to excessive shoot
and leaf growth, while reducing root growth. Nitrogen moves through the
soil quickly and is fast depleted.
Phosphorous provides stimulation for the development of seedlings and the root system. It helps promote early root growth and plant vigor. Since phosphorus tends to bind tightly with soil particles, it moves very little in the soil. Soils rich in this nutrient rarely need it added through a fertilizer.
Potassium helps promote the lawn’s disease and drought tolerance. A lack of this nutrient leads to an increase of turfgrass disease and a reduced tolerance to environmental stress. Potassium also moves very little in the soil, although in certain soils, it can move below the root system.
If you’re not sure of the N-P-K ratio you should be using, there are several resources at your disposal. “Every state has university extension services; their job is to pass on technical research to the public,” says Bill Hoopes, of Scotts LawnService, in Marysville, Ohio. “The extension service can recommend the ratio of N-P-K that’s used in your area. You do not need to design bags of fertilizer.”
Another good source of information says Hoopes is your local fertilizer distributor. “Just ask him ‘what have you got for spring turf fertilization?’ They’re pre-blended products for sale by commercial distributors in every city in this country.”
If you’re still in doubt after consulting with your local state extension service or fertilizer distributor, testing by a soil fertility laboratory will provide you with a conclusive analysis of a soil’s nutrients. Once you’ve tested the soil, you really don’t need to test every lawn you’re working on because soils do not vary significantly from one lawn to the next within a tight geographic location.
After determining the N-P-K ratio, your next decision will involve whether or not you need to use just straight fertilizer, or one that’s blended with herbicides. For the spring application, there’s a good chance you’ll need to use a fertilizer that’s mixed with a pre-emergent herbicide. That’s because spring is when crabgrass rears its ugly head.
Crabgrass is an annual weed that germinates when the ground temperature reaches 60 degrees Fahrenheit. Fertilizer mixed with a pre-emergent herbicide prevents that from happening, but it is ineffective once germination takes place.
The advantage to using a fertilizer mixed with an herbicide is that it reduces the labor involved in lawn maintenance. But great care should be used when applying these products. Fertilizer use should always be a scheduled part of lawn care maintenance, but herbicides should only be used when specific weed problems occur. The application of herbicides and pesticides in your area may require certification. You should check on the local and state regulations.
The first application of fertilizer in the spring will have a lasting effect on how the lawn prospers into the summer months. “That first treatment, no matter where you live,” says Vic Yeandel of TruGreen in Memphis, Tennessee, “is really about bringing the lawn out of dormancy and dealing with potential weed problems.”
Just as important as when you apply the fertilizer is how you apply the product. “It’s critically important that you apply it properly,” says Hoopes. “It doesn’t matter how high the quality of the product you buy if you do not apply it right. A lot of people don’t understand this and are not very skillful at fertilizer application.”
Using a properly calibrated professional rotary spreader ensures that you apply the fertilizer at the correct rate. The spreader should have come with a calibration gauge, but if not, there’s a simple way to check that it’s working properly. You take a measured amount of fertilizer to cover a predictable number of square feet, run it through the spreader, and see if it’s being applied accurately. If not, make the proper adjustments necessary to lay down the right amount of product.
You also want to make sure that when applying the fertilizer mix, you properly overlap from one pass to the next to avoid streaking the lawn. Otherwise it will end up looking like the American flag! You also need to be very thorough when making the bordering pass around curbs and driveways, because that’s where the turf usually is thinnest and where the weeds and crabgrass come in first.
An important consideration is whether to use a quick release or slow release fertilizer. A quick release fertilizer supplies nitrogen to the soil soon after application and produces a rapid response in turf growth and color. A slow release fertilizer depends on the soil process to gradually release the nitrogen. The rate of release is affected by soil temperature, moisture and activity of soil micro-organisms. Generally speaking, slow release fertilizers can be applied at a higher rate with a lower leaf burn potential.
“If you’re using a completely water soluble, or quick releasing fertilizer,” says Hoopes, “then all the nitrogen is going to be released into the turf in a few days. In addition, you run the risk that the grass will grow like crazy, and go through what we call ‘luxury consumption and surge growth.’ You’re growing the blades at a very rapid rate, which will cause excess mowing, and over time can thin out the root system.”
Unless you need that quick growth spurt, it’s probably best to use a fertilizer with a blend of quick and slow release properties that release nitrogen predictably over a period of weeks. While that first application of fertilizer is important, it is only the beginning of the work that’s ahead of you as a landscape maintenance professional.
“When you talk about the preparation and transition of a client’s landscape from the dormancy stages to spring,” says Yeandel, “it’s really about the right mix of fertilization and weed control. After that, additional treatments are necessary.”
“Throughout the year, different application techniques are used,” says Yeandel. “In the summer, with less moisture, granular fertilizer can be really good because the moisture at lower levels can evenly disperse fertilization or weed controls. Different grass types, different regions of the country, as well as different weather patterns determine the necessity of what application is used.”
Ultimately, it’s not just about the application techniques, but also knowing what you’re doing. On an average, experts recommend a six application program throughout the year, with each application differing in methodology, chemistry, fertilization and weed control, depending upon the weather conditions and time of year.
“What I’m concerned about are people who get into this business and portray themselves as lawn care professionals when they’re not,” says Hoopes. “If they want to do this, they should join the Professional Landcare Network (PLANET). They should involve themselves in training, take one of their certification courses, and then go out and do it.”“The people who present themselves as experts and are not, give the industry a bad name. There’s more to this than just throwing some fertilizer around. We do not want amateurs in this business. If we do anything to harm the environment, we are dead ducks. The environment is too important.”