Lawnfertilizers.com - An Informational Site From Seedland.com
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Lawn Grasses grow the best on a nutrient ratio of 3 parts nitrogen, 1 part phosphorus, and 2 parts of potassium. (12-4-8). While this is an ideal ratio you
may not be able to find the exact ratio in a lawn fertilizer. We would suggest that you try to use a fertilizer that has a close ratio match. A soil test would be the optimum way to determine what type of fertilizer, if
any, that you need. Also be aware that fertilizer applications may affect soil pH. Soil tests are not exclusively used to determine nitrogen amounts due to the many climatic,
chemical and biological factors that affect the amount of nitrogen in the soil at any given time. Nitrogen results are thus based on research results from field experiments to
determine the optimum application rate for turf or lawn grass.
The high nitrogen level in a fertilizer gives lawn grass fast shoot development and makes for a deeper green color. The phosphorus provides nutrition for good root development, and
the potassium helps the roots build an immune system against diseases. The amounts of each ingredient will be different for various products, but the ratios needed by your lawn grass will
remain basically the same over time.
To use a fertilizer ratio calculations worksheet, please see this PDF document.
Make sure the lawn fertilizer you apply has complete nutrients in the bag and not just Nitrogen, Phosphate and Potash (N-P-K). Plants often
need micronutrients such as iron, manganese, zinc and boron to meet essential growth requirements. A soil test can help make determine what elements need to be applied. Often iron is in
critical shortage for alkaline soils and is a needed element for many warm season grasses. Seedland sells Pennington Lawn Fertilizer that
includes other trace elements that may be needed for your lawn such as iron.
established lawns are fertilized with a weed & feed
to control weeds and feed your lawn grass at the same time. Over time as your weed problem is reduced, you can usually switch to a
fertilizer without the chemical control of a weed &
feed. It is important that you read the directions on the container of weed and feed products and clearly determine that the
product is suitable for your grass species. Never apply a weed and feed product to a new lawn, instead use a product such as
Pennington Lawn & Grass Plug Starter sold online by Seedland.
New Lawn Starter Fertilizer
New lawn starter fertilizer should be your choice when planting seed or grass plugs in a new lawn. With an analysis of 18-24-6 you will get the
phosphorous needed to establish a good root system and potassium to protect this new root system. The nitrogen contained in this fertilizer will assist with grass leaf or shoot development
while ensuring a nice green color. This fertilizer also contains these additional elements - Boron, Iron, Zinc, Copper, and Manganese.
Calculating Fertilizer Ratios*
If your soil test report recommends applying 1.5 lb of nitrogen, 0.5 lb of phosphate, and 0.5 lb of potash per 1000 sq ft, you should apply a fertilizer with a ratio of 3-1-1 since you need three times as much nitrogen as phosphate and three times as much nitrogen as potash. The simplest method of determining a ratio is to divide the weights of nitrogen, phosphate, and potash by the lowest weight of the three.
You can also determine fertilizer ratios from fertilizer numbers by dividing the percentage of nitrogen, phosphate, and potash by the lowest percentage of the three nutrients.
*Courtesy of Penn State AG Sciences Department
Yearly Fertilizer Rates For Grass Lawns
See the chart below to determine how much fertilizer to use on your particular lawn grass species per year.
Please note that if you have planted a lawn grass mixture (multiple grass types) year long fertilization rates must be applied by establishing which grass species is the dominant grass and fertilize according to the needs of that
Most all charts will give the rates in pounds of nitrogen per 1000 square feet for the growing season (year). We recommend a soil test to determine the additional, if
any, nutrient needs of your lawn
Lawn Grass Fertilization Rate Chart By Species
Lbs / 1000 sq. ft. of N per year.
|BAHIA GRASS -
Pensacola & Argentine
|BERMUDA - Hybrids &
|FESCUE - Tall
|FESCUE - Fine -
Creeping - Chewings
|RYE ANNUAL & PERENNIAL
Calculating Fertilizer Rates For Lawn Grass
From the chart above of "lbs. per 1000 sq. ft" of
Nitrogen you can calculate the amount of fertilizer you actually
need during a year. For example, if you have bluegrass under average
maintenance you would need 3 lbs. of N yearly according to the
Calculate Actual Fertilizer
Application For 1 Complete Year
Total Fertilizer For Multiple Applications
The first number in a fertilizer analysis is the nitrogen percentage. A bag of 25-4-6 fertilizer has 25% Nitrogen per bag. Divide this N amount into the lbs. per 1000 rate from the
chart above. In this case divide 3 by .25 = 12 (use decimal conversion on the percentage i.e.: 25% = .25 )
This means that 1000 sq. ft. of your lawn would require 12 lbs. of this analysis of fertilizer in a YEARS time. This rate would provide a mid-range of maintenance (average) on a Bluegrass
lawn. Thus under a mid-range maintenance plan, you would fertilize twice a year. Therefore you need to apply 6 lbs. of actual fertilizer per application twice a year per 1000 sq. ft. of
your lawn --- A 18 lb. bag of lawn fertilizer, such as the one we sell, covers 5000 sq. ft.
Calculate Amount Of Fertilizer
Per Application - For Each 1,000 Sq. Ft.
Divide your fertilizer nitrogen analysis ( the first number) into 100. If the
analysis is 27% Nitrogen. 100 divided by 27 = 3.71.
That means you would need to apply 3.71 lbs. per 1000 sq. ft. to
apply an actual rate of 1 LB of Nitrogen per application.
High Input Grasses
Grasses being highly maintained such as for golf courses and athletic
fields will need more fertilization according to the intensive
upkeep that is required to promote the fastest and thickest growth
possible. Hybrid varieties such as these are the most care intensive of
the grasses used for turf purposes. Fertilization programs
based on weekly, bi-weekly or monthly applications are often
required to maintain the grasses at optimum growth.
Make sure the lawn fertilizer you apply has complete
nutrients in the bag and not just Nitrogen, Phosphate and Potash
(N-P-K). Plants often need micronutrients such as iron,
manganese, zinc and boron to meet essential growth
requirements. A soil test can help make determine what
elements need to be applied. Often iron is in critical
shortage for alkaline soils and is a needed element for many warm
Applying or Spreading Fertilizer
The best way and easiest way
to distribute fertilizer is with a hand held spreader for small
areas and a lawn drop spreader for larger areas. This evenly
distributes the coverage needed. Avoid applying fertilizers by hand.
Many larger lawns are fertilized with a push broadcast spreader such as the one pictured at right. You should calibrate your spreader using the manufactures
instructions included in new spreaders
Even distribution is the main goal you should
work toward in lawn fertilization. Any overlapping
should be 100 % to avoid uneven coloring, growth and/or
burning. Always fertilize when the grass is dry. Fertilizers are
applied to the grasses according to the growing
season. The warm season grasses receive more fertilizer on the average than the cool season grasses. Cool season grass must prepare food storage for the winter and don’t need the
excess growth that nitrogen brings in creating excess foliage above ground for their root system to support.
a beautiful tomorrow!®