It’s Time to Fertilize

Is your lawn a bit lackluster?  After a long summer of bugs and fungus, it could be.  September is an ideal time to feed turfs, because the cool nights and warm days favor its growth and development.  Because bluegrasses naturally send out more rhizomes in fall than in summer, lawn recovery is enhanced with fall fertilization.  Tall fescue lawns will benefit as well.


Apply a slow release nitrogen product to the turf now at the rate of 0.75 lb. of actual nitrogen per 1,000 sq. ft.  To calculate the pounds of fertilizer product needed to deliver this rate, divide the pounds of nitrogen/1000 ft. desired by the first number in the fertilizer analysis expressed as a percentage. Next, simply multiply the fertilizer needed/1000 sq. ft. by the number of 1000 sq. ft. units in your lawn.  For example, if 0.75 lb. N/1000 sq. ft. if desired on a 5000 sq. ft. lawn and you are using 28-3-6 fertilizer, the first calculation is 0.75/0.28, which equals 2.67 lbs. of product per 1,000 sq. ft.  Next, multiply 2.67 lbs. times 5 to determine that 13.39 lbs. of fertilizer should be applied to the lawn.  This final calculated amount can be rounded up or down slightly to help with weighing out of the product.  A simple kitchen scale can be used to weigh out the correct amount.


Hm…what if I just set the dial on the recommended number on the lawn spreader and start walking over the lawn with the product?  If the fertilizer product makes specific recommendations for the specific brand of spreader that you are using, it’s a fairly reasonable approach.  The spreader can be out of calibration, delivering too much or too little because of wear and tear, but overall, it’s a decent way to apply the fertilizer.  However, if the fertilizer bag does not have a listing for the specific spreader being used, there is no way to know which setting should be used.


If the specific information is not on the bag, the light, medium and heavy approach should be used, with the 0.75 lb./1,000 sq. ft. recommendation above in the medium-heavy range.  Calibration of the product will begin with setting the dial to about 2/3rds of the way from light to heavy, and applying the amount for a thousand square feet to a pre-marked area of the lawn.  If there is leftover product in the spreader hopper after the application, the setting was too light.  If you run out of product before covering the 1,000 sq. ft. area, it was too heavy.  Make adjustments accordingly and re-calibrate and finish the application.

John Fech
Horticulture Extension Educator at Nebraska Extension
John Fech is a horticulturist with the University of Nebraska-Lincoln and certified arborist with the International Society of Arboriculture. The author of 2 books and over 200 popular and trade journal articles, he focuses his time on teaching effective landscape maintenance techniques, water conservation, diagnosing turf and ornamental problems and encouraging effective bilingual communication in the green industry. He works extensively with the media to extend the message of landscape sustainability, making over 100 television and radio appearances each year.
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