Fertilization

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Certain maintenance requirements are necessary for the best quality lawns. Basic chores for having a quality lawn include proper fertilizing, watering, mowing, and controlling weeds, diseases, and pests.  These are our specialties at AMJ.

Fertilization – Why?  How Much?  When?

Fertilization does more to improve poor quality turf and maintain good quality turf than any other single lawn turf management practice. Grass is a plant which normally need nitrogen, phosphorus (phosphate), and potassium (potash) in greater amounts than can be supplied naturally from soil. The only way to determine how much phosphate (P 2 O 5 ) and potash (K 2 O) is required by turf is from a soil test. It’s only $60 and is required by Maryland law every three years.

Fertilization - Manage Your Lawn

The quality of turf depends on color, density, and absence of insects and disease. Color has long been overrated as a standard for a quality lawn. Over fertilizing to get dark green color generally leads to problems. Sod density and absence of insects and diseases are just as important as turf color, and controlling these leads to darker, thicker lawns naturally.

Several applications of fertilizer may be necessary to apply the total amount recommended by the soil test report. For example, if the soil test report recommends 100 pounds of lime per 1,000 square feet, you should split the amount into two applications, each using 50 pounds per 1,000 square feet. Winter is a great time for lime. It breaks down slowly and there is less chance it will wash away in a storm.

Soil acidity varies according to soil type. A soil test shows the soil acidity level, commonly referred to as “soil pH.” The degree of soil acidity is indicated by pH numbers ranging from 1 to 14.

Maintaining a proper pH for your lawn grass is important, because soil pH determines how the soil nutrients are used. Fertilizers work much better when you keep the proper pH.

Nutrients Are Needed

The major nutrients needed for quality lawns are nitrogen, phosphorus, potassium, and iron. All are needed for quality turf, but some are more important than others. Grasses use nitrogen more than any other nutrient; however, the State of Maryland has banned the use of Nitrogen as we do our part to protect the environment.   2014 was the first year where the fertilizer manufacturers have made the necessary changes to comply.

Some soils in Maryland indicate a need for phosphorus. However, many soils will have enough phosphorus for most lawn grasses. Soil testing can identify the existing levels of phosphorus in your soil. Don’t add phosphorus unless the soil test shows the need.

Potassium is also called potash. Most soils in Maryland need it. Potassium is important for proper maturity of turfgrasses. In addition, it helps prevent winter injury and susceptibility to disease.

An important nutrient often overlooked is iron, which is necessary for proper growth and color. In soils with a high pH, iron is often lacking (turf looks yellow-green, similar to lack of nitrogen). You can correct an iron deficiency with granular or foliar fertilizer products. Popular materials to add include iron sulfate, chelated iron, and specialty fertilizers with iron added.

Turfgrasses use various amounts of the different nutrients and the soil test is the only way to know how to customize the blend for your yard.

When should you start fertilizing your lawn?

Ideally, we should not apply the fertilizer until the turfgrass is actively growing and can readily use the nutrients. Arguments that support this theory include not encouraging weed growth, reducing loss of nutrients to erosion, and not encouraging rapid, succulent growth that can be damaged by a cold snap or requires multiple mowings each week until it uses up the nutrients.  Remember, the goal is a dense, lush lawn that protects itself from disease and weeds not the tallest lawn in town. 

There is a problem with early fertilization because if the weather gets into a repeated cycle of temperatures warm enough to start top growth, but too short to provide carbohydrates to the young roots. The young leaves can be destroyed by the cold during this cycle trying to enjoy the fertilizer but and all of the carbohydrates stored over the winter will get used up in this process causing the roots to die from lack of food. 

Our preference is to provide a slow release Winter Fertilizer which not only provides the carbs needed for the plant to survive and continue growing roots but also store enough energy until pre-emergent controls can be applied in Spring.  The benefit is that your lawn has a nice growth spurt in the Spring and color comes back without the excessive height produced by Spring Fertilizations.

This option makes it possible to use “weed and feed” formulations since the pre-emergent fertilizers need to be out before germination of the weed seeds. We can achieve an even distribution of preemerge weed control most easily with these herbicide-carrying fertilizers.

Slow-release fertilizers offer the best of both worlds. The fertilizer is made available over an extended period of time and will help prevent flushes of rapid growth but will supply additional nutrition for the turfgrass to maintain a consistent state of health.

Liming

Most turfgrasses prefer a soil pH ranging from 6.0 to 7.0. If the soil is too acid for proper turfgrass growth, lime may be applied. Lime should be applied in accordance with a soil test recommendation. The lime requirement should be met by applying ground agricultural limestone. Fall applications are preferred as rain, snow, and freezing/thawing of the soil during the winter aid in working the limestone into the soil. Late winter is also a good time to apply lime.

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