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S D SU D EPA R T M EN T O F
P L A N T S C I EN C E
O C T O B E R 2 013
Fertilizing South Dakota Lawns –
A 10-Point Checklist for Cool Season Grasses
David Chalmers | Professor & SDSU Extension Turfgrass Associate
Home consumers often orient their thinking about
lawn fertilizer applications to begin in the spring. Yet,
late season is the best time to fertilize cool-season
grasses. Consider planning lawn fertilizer applications
to begin in the late August to early October period.
Spring fertilizer application timing and the rate of
nitrogen to apply is influenced by what was or was
not applied during September and early October. This
checklist can help you make decisions on fertilizing
your lawn so that it will be healthy and attractive yet
minimize the damage to the environment.
 1. Determine the amount of work and money
you want to spend on managing your lawn.
Management levels are broadly defined as:
• Low: the minimum level of management required
to maintain turf density. This varies with grass
types and use.
• Moderate: the level required for enhanced density,
visual appearance and quality.
• High: the level needed for lawn areas that are
highly visible or must withstand and recover from
high traffic or use.
 2. Measure your lawn and refer to its size when
buying lawn care products. Lawn care products
are usually recommended and applied in measured
amounts per 1,000 square feet. If you know the size of
your lawn, you are less likely to buy and apply too little
or too much fertilizer. Start by measuring each section
of your lawn in square feet. Then add up the sections
to arrive at the total size of the lawn in square feet.
(Figure 1)
 3. Test the soil every 3 to 4 years. The soil
test will not provide an annual recommendation for
F i g u re 1. T h i s l a w n h a s b e e n d i v i d e d i n t o n i ne
s e c t i o n s s o t h a t t h e s q u a re f o o t a g e c a n b e c a lcula t e d
nitrogen application. Nitrogen is the nutrient used in
the greatest amount by lawn grasses. This publication
will guide you to apply measured amounts of nitrogen
fertilizer that would benefit your lawn. Annual nitrogen
fertilizer rates are described in Table 1. Soil tests enable
you to know if any other nutrients might be deficient in
the soil. Soil test reports provide recommendations for
applying fertilizer nutrients that are deficient.
 4. Choose a fertilizer products based upon soil
test recommendations. If you do not have a current
soil test, apply nitrogen using a fertilizer analysis
ratio (the three numbers that appear on the fertilizer
package represent N:P 205 :K 20) that is four to six parts
nitrogen (N), one part phosphorus (expressed as
available phosphoric acid, or P205 ) and two to four parts
potassium (expressed as soluble potash, or K 20).
 5. Match the annual nitrogen application
program to your grass type, lawn management
level and inputs. The level of management (low to
moderate to high) is based on the annual nitrogen
needs of the type of grass (Table 1) and the
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expectations for lawn quality. In South Dakota, coolseason lawn grasses include Kentucky bluegrass,
fineleaf fescues (creeping red, hard and chewings
fescue), and possibly tall fescue. The nitrogen
requirements differ for each type. The annual amount
of nitrogen lawns need is best split into single
applications of 1 pound of nitrogen or less per 1,000
square feet. Fertilizer products may state how much
area the bag of fertilizer will treat (e.g.; 5,000 sq.
ft.) Manufacturer statements on the amount of area
treated often equate to applying 3/4 to 1 lb of actual
nitrogen per 1,000 square feet.
Table 1. Annual nitrogen rates for South Dakota coolseason lawns by management level and grass type.
Ranges of Lawn Management
Annual N Rates
Low
Cool-season lawn alone
or mixed
Kentucky bluegrass
Moderate
High
lbs nitrogen applied per 1,000
sq. ft. per year
2
3
4
2
2-3
3-4
Fine fescue
1
2
NR*
Tall Fescue
2
3
4
Kentucky bluegrass +
fine fescue
*NR = not recommended
 6. Know how much total lawn fertilizer is
needed for any single application by using Table 2.
Lawn fertilizer is applied so that no more than 1 lb of
actual nitrogen is applied per 1,000 sq. ft. in any one
application.
• Find the fertilizer analyses in the first column.
• Select an application of 1/2 to 1 pound of nitrogen
fertilizer per 1,000 square feet of lawn. Nitrogen
favors green color, turf density and top growth
(clippings).
• Find the number of pounds of the fertilizer product
to buy for each 1,000 square feet of lawn area
in the row opposite the nitrogen analysis in your
fertilizer.
Note: The fertilizer analyses listed in Table 2 leaves
phosphate (P 205 ) and potash (K 20) blank. The P205 and
K 20 needs are best determined by a soil test.
Table 2. Pounds of fert ilizer product s to
needed to apply rates of ½ , ¾ and 1 pound
of nit rogen per 1,0 0 0 square feet of lawn
area.
Fertilizer Bag Reads
1/2 lb N
3/4 lb N
1 lb N
6-?-?
8.3
12.5
16.6
8-?-?
6.2
9.4
12.5
10-?-?
5.0
7.5
10.0
15-?-?
3.3
5.0
6.6
20-?-?
2.5
3.7
5.0
21-?-?
2.4
3.6
4.8
29-?-?
1.7
2.5
3.4
 7. Know how to determine the right amount
of fertilizer to buy no matter what the analysis
(numbers on the bag). Using a 40-pound bag of 164-8 as an example, you can determine the percentage
and pounds of each nutrient supplied in that 40-pound
bag by multiplying 40 pounds by the percentage in
decimals (0.16, 0.04, and 0.08):
• Nitrogen (N) = 16% (40 x 0.16 = 6.4 lbs of N is
supplied)
• Phosphorus (P 205 ) = 4% (40 x 0.04 = 1.6 lbs of
P205 is supplied)
• Potassium (K 20) = 8% (40 x 0.08 = 3.2 lbs of K 20
is supplied).
At the 1-pound rate of nitrogen applied per 1,000
square feet, the 40 lbs of fertilizer in the bag could treat
6,400 square feet of lawn. At that rate 0.25 lb of P 205
and 0.5 lb of K 20 per 1,000 sq. ft. would be applied
along with the nitrogen. Use Table 2 to help match the
amount of nitrogen in the fertilizer to the target rate of
N to apply per 1,000 square feet of lawn.
 8. Know when to first apply fertilizer late in the
growing season and/or spring. Make the first spring
application of fertilizer after the second or third mowing
of lawn grass (not weeds). At this time, the grass is
actively growing and can readily use applied nitrogen.
This application may be delayed further if fertilizer
was applied in September or October. See Table 3 for
timing seasonal fertilizer application, application priority
and nitrogen rates for cool-season grass lawns based
upon lawn management level.
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 9. Know when to consider if additional fertilizer
is needed above what is normally applied. Space
any supplemental nitrogen applications at least 30
days apart. Newly established, previously neglected
or higher maintenance lawns can benefit from such
applications.
•
 10. Know when to apply the late season fertilizer
in the August 25 to October 10 late season time
frame. Late season is the best time to fertilize. Yet,
turfgrasses need good soil moisture from rainfall or
irrigation to make the most of the fertilizer. Late season
nitrogen fertilizer applications allow for good fall and
spring growth, increases in turf density and green
color. With late season nitrogen fertilizer applications,
the timing of the spring fertilizer application can often
be delayed until after the normal spring growth surge.
This can help reduce spring mowing that results from
too much early spring nitrogen fertilizer. The suggested
dates by which to apply your last fertilizer application
are listed in Table 3.
Nitrogen Fertilizer Sources:
There are two categories of nitrogen sources: quickly
available and slowly available. The source of nitrogen
influences how quickly nitrogen can be used and how
the grass responds to it. Quickly available nitrogen
fertilizers are water-soluble and can be readily used
by the plant, resulting in faster green-up. They are
also susceptible to leaching and have a relatively
short period of response of 4 to 6 weeks. Quickly
available sources include urea, ammonium sulfate and
ammonium phosphates. These sources are typically
less expensive forms of nitrogen, and this will be
reflected in fertilizer costs at the garden center.
Other Things To Consider
Application Tips
• Don’t fill the spreader with fertilizer while on the
lawn as spills can burn the grass.
• Always be moving when you open the spreader
gate to apply fertilizer.
• Do not apply fertilizer to sidewalks, driveways or
curbs. If the fertilizer gets on hard surfaces, sweep
or use a powered blower—don’t hose—it back into
the grass. This will prevent runoff.
•
Irrigate fertilizer applications with a normal
irrigation cycle so the nutrients enter the soil to
prevent runoff.
Lower nitrogen rates are appropriate not only for
low-maintenance lawns, but also for lawns in
environmentally sensitive sites
Any slowly available portion of the total nitrogen in
the fertilizer releases nitrogen over extended periods
of time and can be beneficial. If slow-release nitrogen
sources are in a fertilizer, they will be listed on the
label and they cost more than readily available N
sources. For home consumer markets slowly available
N sources can be absent or up to 20 to 30% of
the N in the fertilizer. They most often include urea
formaldehyde (UF), methylene urea, sulfur-coated urea
(SCU) and polymer-coated urea.
Table 3 . Annua l ni t rogen fert i l i zer program s b a s e d u p o n l awn ma n a ge me n t l e ve l .
Ra t es a nd pr ior it y t i mi n g o f N a p p l i c a t i o n ( l b s o f N p e r 10 0 0 s q . ft . ) a s
p a r t o f t h e a n n u a l N p r o g r a m*
To t al an n u al
N in lbs per
1 , 0 0 0 sq . ft .
1s t
2nd
3rd
4th#
Aug 25 t o Sept
10
Se p t 2 5 t o O c t
10
May 1 t o 15
( A ft e r 3 r d
mow i n g )
Ju n e 1 t o Ju n e
15
Low In pu t
¾ to 1
½ to 1 Apply
her e o r May 1- 15
½ to 1 Apply
here or Sept. 25
t o O c t 10
none
1 ¼ to 2
Mo de rate Inp ut
¾ to 1
¾ to 1
½ to 1
none
2 to 3
Hig h In pu t
¾ to 1
¾ to 1
¾ to 1
If Needed
2 ¼ to 4
L awn Man ag ement
Leve l
* Warm er p ortio ns of Sout h Da kot a would beg i n fe r t i l i zi n g e a r l i e r i n t h e s p r i n g a n d l a t e r i n t h e l a t e s e a s o n p e r i o d .
Coo ler Sou th Dakot a loc a t ions would fer t ilize l a t e r i n t h e s p r i n g a n d b e g i n e a r l i e r i n t h e l a t e s e a s o n p e r i od .
# A late sprin g (June) fer t ilizer a pplic a t ion m ay b e n e e d e d fo r n ew l y s e e d e d l aw n s o r a r e a s t h a t n e e d t o r e cove r
from excessive u s e or ot her da m a ge.
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Shade: Grasses growing in moderate to heavily
shaded areas require only 1/2 to 2 ⁄3 as much nitrogen
as grasses growing in full sun.
Recycling grass clippings: When you recycle
clippings on site significant amounts of nitrogen,
phosphorus and potassium are returned to the lawn.
Recycling clippings enables you to apply less fertilizer
to keep your grass healthy.
Watersheds and nutrient management: At-risk
watersheds are areas that are especially vulnerable to
water quality problems. Special care must be taken to
manage nutrients so that you reduce the potential loss
of phosphorus (from runoff) and nitrogen (from runoff
and leaching into the groundwater).
•
For a section of lawn that measures 2,000
square feet, place 22 pounds of 9-?-? fertilizer
in the spreader.
• The only tools you need to weigh the fertilizer
in “measured amounts” are a bathroom scale
and a large bucket.
5. Cut back the spreader setting to the smallest
opening that still enables a good distribution
pattern from your spreader.
6. Apply the measured amount of fertilizer, using the
spreader to apply it in one direction and then the
next at right angles, repeating until the measured
amount of fertilizer is gone. Although this may take
three or four passes, it is easy to do and applies
the fertilizer uniformly, in “measured amounts.”
New lawns: Lawns that are newly established or
recovering from damage will benefit from properly
timed applications of nitrogen until the ground cover
and density have reached a desirable level. New lawns
will likely require a bit more nitrogen fertilizer the first
year or so after planting.
Working with fertilizer spreaders: Fertilizer products
will suggest settings on fertilizer spreaders that apply
the fertilizer at the manufacturer’s recommended rate.
This works best when the company that makes the
fertilizer also makes the spreader. If a different rate of
N is desired you might want to follow these steps. It is
an alternative way to manage spreading the fertilizer at
your desired rate.
1. Measure each section of your lawn in square feet.
2. Calculate the amount of the selected fertilizer
product you wish to apply per 1,000 square feet.
(Refer to Table 2)
3. Weigh out only the amount of fertilizer needed for
a section of lawn.
4. Example:
• A 9-?-? fertilizer would need 11 pounds of
fertilizer to apply 1 pound of actual nitrogen per
1,000 square feet.
Summary
Proper and timely fertilization can be good for your
lawn and the environment. Take this measured
approach to lawn fertilization and enjoy the results!
References and acknowledgment
This material was adapted from “Fertilizing Texas
Lawns: 10-Point Checklist for Warm-Season Grasses”
produced by Texas A&M AgriLife Extension Service.
Chalmers, D. R., and J. McAfee. 2010. Texas A&M
AgriLife Extension Service publication number E-436.
South Dakota State University, South Dakota counties, and U.S. Department of Agriculture cooperating. South
Dakota State University is an Affirmative Action/Equal Opportunity Employer and offers all benefits, services,
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Publication: 06-2002-2013
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