TURF TURF FERTILIZINGFERTILIZINGEdited by: Vincent Mannino, County Extension

Director

Texas AgriLife Extension Service

Fertilizing Your Texas Lawn Introduction continued:

This training will teach you how to best fertilize This training will teach you how to best fertilize your lawn by considering:your lawn by considering:

Your Texas location and growing season Your Texas location and growing season Your grass species; whether cool-season or warm Your grass species; whether cool-season or warm

seasonseason Soil testing to determine fertilizer selectionSoil testing to determine fertilizer selection The maintenance level and expected “quality” The maintenance level and expected “quality” Whether in open sun or shadeWhether in open sun or shade

The Take Home Message:The Take Home Message: Being able to tell a Being able to tell a homeowner go to the garden center and pick homeowner go to the garden center and pick the right fertilizer and apply it to your lawn in the right fertilizer and apply it to your lawn in an environmentally sensitive seasonal programan environmentally sensitive seasonal program

WhatWhat do I need to know to fertilize my lawn? do I need to know to fertilize my lawn? This one question is a puzzle of many pieces!This one question is a puzzle of many pieces!

Most homeowners ask…Most homeowners ask…

1.1. Why should I fertilize my lawn? Why should I fertilize my lawn? 2.2. What do I need know about my lawn (soil What do I need know about my lawn (soil

type, grass type, shade)?type, grass type, shade)?3.3. What do I need to know about fertilizers?What do I need to know about fertilizers?4.4. How do I choose a fertilizer for my lawn? How do I choose a fertilizer for my lawn? 5.5. How much fertilizer should be applied?How much fertilizer should be applied?6.6. When should I fertilize when my lawn? When should I fertilize when my lawn? 7.7. How often should fertilizer be applied?How often should fertilizer be applied?8.8. What is this I hear about environmental What is this I hear about environmental

issues and fertilizer application?issues and fertilizer application?

Let’s try to answer these questions…Let’s try to answer these questions…

WhyWhy should I should I fertilize my lawn?fertilize my lawn?

Knowing the right “ins and outs” of Knowing the right “ins and outs” of how how to fertilize effectivelyto fertilize effectively almost always: almost always:

► Is the basic component of having a Is the basic component of having a quality lawn!quality lawn!

► Helps you apply appropriate amounts Helps you apply appropriate amounts ► Helps favor root growth and Helps favor root growth and

“unforced” leaf growth and limits “unforced” leaf growth and limits thatch buildupthatch buildup

► Uses water more efficientlyUses water more efficiently► Helps lawns better tolerate moisture Helps lawns better tolerate moisture

stress stress

WhatWhat do I need do I need know about a know about a

lawn?lawn?

A: soil type, grass A: soil type, grass type, shadetype, shade

How? How? ► You find out what nutrients in your landscape soil You find out what nutrients in your landscape soil

are either deficient or in excess.are either deficient or in excess.► Soil acidity (pH < 7.0), alkalinity (pH > 7.0) and Soil acidity (pH < 7.0), alkalinity (pH > 7.0) and

saltssalts► You are provided with a recommendationYou are provided with a recommendation► It protects from over application of Phosphorus It protects from over application of Phosphorus

and possible movement with storm-water and possible movement with storm-water ► You will know what nutrients your soil needs, if You will know what nutrients your soil needs, if

salts are a problem and fertilize salts are a problem and fertilize recommendation? recommendation?

Where can I get my soil tested?Where can I get my soil tested? ► Contact your local County Extension office.Contact your local County Extension office.► Or visit the following web site.Or visit the following web site.

http://soiltesting.tamu.eduhttp://soiltesting.tamu.edu

How can soil testing How can soil testing help? help?

► Soil test usually indicates residual N Soil test usually indicates residual N in that can contribute to plant growth in that can contribute to plant growth and and potential water contamination potential water contamination

► However, nitrogen is best applied However, nitrogen is best applied according to recommended annual according to recommended annual programs. programs.

Most Important Part of the Test Nitrogen

(N)

Let’s talk about the nutrient most often applied Let’s talk about the nutrient most often applied - - NitrogenNitrogen

► Nitrogen (N) is the nutrient required in the largest quantity Nitrogen (N) is the nutrient required in the largest quantity and it is applied most often.and it is applied most often. Other nutrients can “come along” with the nitrogen in a Other nutrients can “come along” with the nitrogen in a

“complete” fertilizer or they can be applied separately.“complete” fertilizer or they can be applied separately.

► Typical recommendation in irrigated situationsTypical recommendation in irrigated situations suggest suggest applying up to applying up to 1 LB 1 LB of actual nitrogen per 1000 square feet of actual nitrogen per 1000 square feet per application.per application. More may lead to excessive growth or too much for the More may lead to excessive growth or too much for the

plant to use (potential leaching) plant to use (potential leaching)

► Individual applications added together make up the annual Individual applications added together make up the annual nitrogen rate applied to lawns grassesnitrogen rate applied to lawns grasses

► Grass type, lawn quality, and maintenance level are also Grass type, lawn quality, and maintenance level are also important considerations in determining how much and how important considerations in determining how much and how often you apply nitrogen fertilizeroften you apply nitrogen fertilizer

Annual Nitrogen Annual Nitrogen Recommendations Recommendations

For For Low, Medium and High Low, Medium and High

Maintenance LawnsMaintenance Lawns

Lawn Grass Type (species) LBS Nitrogen per 1000 sq. ft per year

Warm Season Grasses Low Medium High

bermudagrass (common type)

1-2 2-3 3-5

Bermudagrass (hybrid) 2-3 3-4 4-6

Buffalograss 0-1 1-2 NR*

Carpetgrass 0-1 1-2 2-3

Centipedegrass 1/2 1 2

Seashore paspalum 1-2 2-3 3-4

St. Augustinegrass (sun) 1-2 2-3 3-4

St. Augustinegrass (shade) 1/2 to 1 1-2 2-3

Zoysiagrass 1-2 2-3 3-4

ShadeShade

► Grow turf where Grow turf where you can grow turfyou can grow turf

► Grow Ground Grow Ground covers where you covers where you cannotcannot grow turf grow turf

► Fertilizer Fertilizer requirement is 1/3 requirement is 1/3 to 1/2 less for to 1/2 less for shaded sitesshaded sites

WhatWhat do I need to do I need to know about know about fertilizers. fertilizers.

Nitrogen Nitrogen recommendation is recommendation is given in pounds of given in pounds of actual nitrogen per 1000 actual nitrogen per 1000 square feet of lawn area square feet of lawn area Any fertilizer can be Any fertilizer can be used. Fertilizer may be used. Fertilizer may be selected based upon a selected based upon a number of features number of features including the grade including the grade (numbers on the bag: N-(numbers on the bag: N-PP22OO55-K-K22O) complete O) complete fertilizer or by nitrogen fertilizer or by nitrogen source (readily available source (readily available or slowly available) or slowly available) More on this laterMore on this later

It All Starts With That Bag of Fertilizer…It All Starts With That Bag of Fertilizer…

► The numbers on the The numbers on the bag are important!bag are important!

► These numbers are These numbers are referred to as the referred to as the “grade” or minimum “grade” or minimum guaranteed analysis guaranteed analysis

► The numbers in order The numbers in order represent:represent: Nitrogen % by Nitrogen % by

weightweight Phosphate (P2O5) Phosphate (P2O5)

% by weight% by weight Potash (K2O) % by Potash (K2O) % by

weightweight

How do I know what How do I know what nitrogen products are in nitrogen products are in the bag I am looking at the bag I am looking at at the Garden Center?at the Garden Center?

► Look at the other information on the bag

► It will tell you the sources of N in the container

► If slow release N sources are in the bag they will be listed.

► By the way slow release sources will cost more than readily available N sources.

Different forms of Nitrogen Fertilizer Different forms of Nitrogen Fertilizer Which Which is Which? The readily available N sources:is Which? The readily available N sources:

► Readily Available N sources -Readily Available N sources - InorganicInorganic

►ammonium nitrate►ammonium sulfate►ammonium phosphates

Organic:Organic: Urea

► Response time to grass green-up is relatively short.

► Residual activity fairly quickly converted to “available” nitrate nitrogen. MMay last only 4 to 6 weeks depending upon rainfall, irrigation and clipping return

► Under good growing conditions these products may produce high leaf growth rates = more mowing!

Different forms of Nitrogen Fertilizer Different forms of Nitrogen Fertilizer Which is Which? The slowly available sources:Which is Which? The slowly available sources:

► Slowly available nitrogen sources in lawn fertilizersSlowly available nitrogen sources in lawn fertilizers Slowly soluble: IBDU*Slowly soluble: IBDU* Slow release: Slow release:

► Sulfur coated ureasSulfur coated ureas► polymer coated ureaspolymer coated ureas

Microbial release dependent Microbial release dependent (needs warm soil temperatures): (needs warm soil temperatures): ► Urea formaldehyde, Urea formaldehyde, ► Methylene ureasMethylene ureas► Methylol ureasMethylol ureas► Natural OrganicsNatural Organics► Processed sewage sludgeProcessed sewage sludge

► Response time to grass green-up is delayed and product dependent.Response time to grass green-up is delayed and product dependent.

► Residual activity may last 8 to 10 weeks depending upon grass Residual activity may last 8 to 10 weeks depending upon grass species maintaining color, precipitation, irrigation product and species maintaining color, precipitation, irrigation product and clipping returnclipping return

► Less growth surgesLess growth surges* isobutylidene diurea

Knowing how your fertilizer will Knowing how your fertilizer will respond so you can use it properly!respond so you can use it properly!

► Nitrogen fertilizers sold can be:Nitrogen fertilizers sold can be: All readily available NAll readily available N All slowly available NAll slowly available N Or mixtures of readily Or mixtures of readily

available and slowly available available and slowly available N sourcesN sources

► Often homeowner-type fertilizers Often homeowner-type fertilizers are a mixture of readily available are a mixture of readily available N and slowly available NN and slowly available N

► Knowing what proportion of the Knowing what proportion of the nitrogen that is readily available nitrogen that is readily available and what if any is slowly and what if any is slowly available allows you to use available allows you to use nitrogen wisely!nitrogen wisely!

All readily availablenitrogen

All slowly availablenitrogen

Slowly available N

Readily available N

Comparing Nitrogen Sources in Lawn FertilizerComparing Nitrogen Sources in Lawn Fertilizer

Nitrogen Source CategoryCharacteristic Slowly

AvailableReadily

AvailableResponse timeResponse time slowslow quickquick

Burn potentialBurn potential lowlow highhigh

ApplicationApplication more seldommore seldom More frequentMore frequent

Water solubilityWater solubility lowlow highhigh

ResidualResidual greater (varies)greater (varies) shortshort

CostCost highhigh lowlow

Leaching potentialLeaching potential lowerlower highhigh

Surface runoffSurface runoff reduced potentialreduced potential higher potentialhigher potential

Note: yellow are more related to water quality issues

► Slowly available N in the fertilizer are stated on the label. ► In the fertilizer below some N is listed as “WIN” or water

insoluble nitrogen - a type of slow release nitrogen.► The percentage of the WIN nitrogen is 3.6% and is also

stated on a weight basis. Therefore, 3.6 divided by 12 as is 30% - That’s Good! The other 70% is considered readily available

nitrogen.

HowHow do I choose a do I choose a fertilizer for my fertilizer for my

lawn?lawn?

Don’t let all those fertilizers confuse Don’t let all those fertilizers confuse you!you!

22-3-4

Selecting that fertilizerSelecting that fertilizer

► In addition to N, soil test results say:In addition to N, soil test results say: If you need phosphorusIf you need phosphorus If you need potassiumIf you need potassium If you need calcium, magnesium and If you need calcium, magnesium and

other nutrients.other nutrients.► Select a fertilizer ratio to meet your soil Select a fertilizer ratio to meet your soil

needs, but to do so you will need to soil needs, but to do so you will need to soil test!test!

► Find an analysis fertilizer that supplies Find an analysis fertilizer that supplies what is recommended by soil testingwhat is recommended by soil testing

► Do not apply phosphorus if not neededDo not apply phosphorus if not needed► And, soil test will tell the pHAnd, soil test will tell the pH

Fert. FactsFert. Facts

Nitrogen sources influence cost, but also Nitrogen sources influence cost, but also turf responseturf response

Fertilizer manufacturing process will Fertilizer manufacturing process will affect costaffect cost

Consider ease of spreadingConsider ease of spreading Only buy what is needed Only buy what is needed If you have not soil tested you may use a If you have not soil tested you may use a

nitrogen only fertilizer until you can soil nitrogen only fertilizer until you can soil test (more later)test (more later)

How muchHow much fertilizer should fertilizer should

be applied?be applied?

The fertilizer bag says that it will cover The fertilizer bag says that it will cover 5,000 ft5,000 ft22 - do I need to know anything - do I need to know anything

more than that?more than that?

1. Most people do not know how many square feet of lawn they have.

2. You know “1 bag” will cover 5,000 ft2 .

3. You know what the analysis is according to the bag.

4. You do not know what nutrients the soil/plant actually need.

Only testing will tell. Extension agents, specialist, fertilizer salesman are good at GUESSING recommendations.

L

W

Length X Width = sq. ft.

Measure that lawn! Measure that lawn! You only need do it once then you have You only need do it once then you have

it!it!► 1st Step:1st Step: Measure your Measure your

lawn to find out how large lawn to find out how large the turf areas are.the turf areas are.

► The lawn area to the right The lawn area to the right would be the areas would be the areas not not taken uptaken up by the house, by the house, drive, walk, deck and drive, walk, deck and landscape beds.landscape beds.

► The total lot size is 180 Ft. The total lot size is 180 Ft. by 80 ft. = 14,400 square by 80 ft. = 14,400 square feet feet

► The lawn area will be less The lawn area will be less than the total lot size - we than the total lot size - we just need to find out how just need to find out how many square feet of lawn many square feet of lawn there is!there is!

House

Drive

Deck

80 Feet

180 f

eet

Landscape Plants

Lawn

Measure that lawn! Measure that lawn! You only need do it once then you have it!You only need do it once then you have it!

► The total lot size is 180 Ft. by The total lot size is 180 Ft. by 80 ft. = 14,400 square feet 80 ft. = 14,400 square feet

► Sketch the lot.Sketch the lot.► Break up the different lawn Break up the different lawn

areas and multiply length X areas and multiply length X width in ft.width in ft.

► Keeping a record of each Keeping a record of each section of the yard can help you section of the yard can help you “check” your fertilizer “check” your fertilizer application by section. application by section.

► Sections #1 through #5 are Sections #1 through #5 are pretty easy.pretty easy.

► Lawn in areas #6 and # 7 and Lawn in areas #6 and # 7 and to the left and right of the deck to the left and right of the deck also need to be measured.also need to be measured.

► Add up all lawn areas. This Add up all lawn areas. This example shows 8,000 square example shows 8,000 square feet of lawn. feet of lawn.

House

Drive

Deck

80 Feet

180 f

eet

Lawn

#1

#2

#3

#4

#5#6#7

#8 #9

Back to That Bag of Fertilizer and Take Home Back to That Bag of Fertilizer and Take Home Messages…Messages…

Let’s talk about the nutrient most often applied - Let’s talk about the nutrient most often applied - nitrogennitrogen

► Applying this to our example:Applying this to our example: From our example we determined the lawn was 8,000 sq. ft.From our example we determined the lawn was 8,000 sq. ft. 8,000 sq ft. divided by 1,000 sq ft means we have 8 units of 8,000 sq ft. divided by 1,000 sq ft means we have 8 units of

1000 sq ft in our lawn1000 sq ft in our lawn To apply 1 LB of N per 1,000 sq ft to our entire lawn we would To apply 1 LB of N per 1,000 sq ft to our entire lawn we would

then multiply 1 lb N by 8 units of 1000 sq ft to find out our then multiply 1 lb N by 8 units of 1000 sq ft to find out our whole lawn needs a total of 8 LBS of actual nitrogen.whole lawn needs a total of 8 LBS of actual nitrogen.

► Now we learn how to use this information to purchase the right Now we learn how to use this information to purchase the right amount of fertilizeramount of fertilizer..

How much of this fertilizer do we need? Your at the garden center How much of this fertilizer do we need? Your at the garden center looking at fertilizer packages of different N concentrations…looking at fertilizer packages of different N concentrations…

► Step 1:Step 1: Know the rate of N that Know the rate of N that should be applied per 1000 sq ft should be applied per 1000 sq ft of lawn area. We will use 1 LB N.of lawn area. We will use 1 LB N. More on this later…More on this later…

► Step 2:Step 2: Use the number for Use the number for nitrogen on the fertilizer nitrogen on the fertilizer package of choice (20% here)package of choice (20% here)

► Step 3:Step 3: Divide 20% (0.20) into 1 Divide 20% (0.20) into 1 (rate) = 5 lbs. per 1000 sq. ft. to (rate) = 5 lbs. per 1000 sq. ft. to deliver 1 LB. N.deliver 1 LB. N.

► Step 4:Step 4: Calculate the total for Calculate the total for the entire lawn. If we have 8 the entire lawn. If we have 8 units of 1000 sq ft in our lawn. If units of 1000 sq ft in our lawn. If we need 5 lbs of product for we need 5 lbs of product for each 1,000 sq ft that means each 1,000 sq ft that means that we should purchase that we should purchase 40 LBS 40 LBS of the productof the product (5 times 8) and (5 times 8) and evenly apply over the lawn! evenly apply over the lawn!

20% Nitrogen by Weight

Let’s try with another fertilizer at the same rate of Let’s try with another fertilizer at the same rate of N and the same size lawn!N and the same size lawn!

► Step 1:Step 1: 1 Lb N per 1000 sq ft is our goal 1 Lb N per 1000 sq ft is our goal► Step 2:Step 2: 12 is the % N by weight stated 12 is the % N by weight stated

on the labelon the label► Step 3:Step 3: Step 3:Step 3: Divide 12% (0.12) into Divide 12% (0.12) into

1 (rate) = 8.3 lbs. per 1000 sq. ft. 1 (rate) = 8.3 lbs. per 1000 sq. ft. ► Step 4:Step 4: On 8,000 sq ft it would be 8.3 On 8,000 sq ft it would be 8.3

Lbs of fertilizer product times 8 units Lbs of fertilizer product times 8 units of 1000 sq ft = 66.7 LBS of this fertilizer is of 1000 sq ft = 66.7 LBS of this fertilizer is needed for the whole 8,000 sq ft lawn.needed for the whole 8,000 sq ft lawn.

► Yet some P2O5 and K2O were also applied. Yet some P2O5 and K2O were also applied. The nutrient ratio here is 4 - 1 -2. So with our The nutrient ratio here is 4 - 1 -2. So with our 1 lb of N we applied 1/3 LB of P2O5 and 1/2 1 lb of N we applied 1/3 LB of P2O5 and 1/2 LB of K2OLB of K2O

► Did we need that much? Only a soil test will Did we need that much? Only a soil test will tell us that!tell us that!

12% N

The amounts of various types of fertilizers required to apply The amounts of various types of fertilizers required to apply certain rates of N certain rates of N per 1000 sq ftper 1000 sq ft

FertilizerFertilizer

AnalysisAnalysisPounds of actual nitrogen desired/1000 Pounds of actual nitrogen desired/1000

sq ftsq ft

1/21/2 1.01.0 1.5*1.5* 2.0*2.0*

Pounds of fertilizer to apply above N ratePounds of fertilizer to apply above N rate

6-2-0 8.38.3 16.616.6 2525 3333

10-10-10 5.05.0 10.010.0 15.015.0 20.020.0

12-4-8 4.14.1 8.38.3 12.512.5 17.017.0

16-8-8 3.13.1 6.26.2 9.49.4 12.012.0

20-0-16 2.52.5 5.05.0 7.57.5 10.010.0

23-3-7 2.12.1 4.34.3 6.56.5 8.68.6

28-0-12 1.81.8 3.63.6 5.35.3 7.27.2

31-0-0 1.61.6 3.23.2 4.84.8 6.46.4

38-0-0 1.31.3 2.62.6 3.93.9 5.25.2

46-0-0 1.11.1 2.22.2 3.23.2 4.44.4

* These rates only for use with slowly available N sources

When When should I should I fertilize when my fertilize when my

lawn?lawn?

What “growing season” zone What “growing season” zone are you in?are you in?

► When you start fertilizer When you start fertilizer application and when application and when you stop depends on you stop depends on where you are in Texaswhere you are in Texas

► It matters for both cool It matters for both cool season and warm season season and warm season grassesgrasses

► The goal is to fertilize The goal is to fertilize when the grass is when the grass is actively growing, and can actively growing, and can best use the nutrientsbest use the nutrients

► Explanation of Explanation of growing season zones growing season zones follow…follow…

Knowing the “Growing Season” in your part of Knowing the “Growing Season” in your part of Texas is the first step in knowing when to apply Texas is the first step in knowing when to apply

fertilizerfertilizer

► The length of the The length of the growing season is growing season is “roughly” the time “roughly” the time between the last chance between the last chance of frost in the spring to of frost in the spring to the first chance of frost the first chance of frost in the fall.in the fall.

► The growing season The growing season indicates temperatures indicates temperatures are warm enough for are warm enough for grass growthgrass growth

Growing Seasons as Growing Seasons as determined by Spring determined by Spring and Fall Frost Datesand Fall Frost Dates

ZonesZones Last Spring Frost

First Fall Frost

NN Jan. 30 to Feb. 14 Dec. 16 to no freeze

WW Feb. 14 to March 1 Dec. 1 to Dec. 16

SESE March 1 to March 16 Nov. 16 to Dec. 1

SS March 16 to March 31 Nov. 1 to Nov. 15

FertilizingFertilizingthe Warm Season Grasses the Warm Season Grasses

► Bermudagrass (common type)Bermudagrass (common type)► Bermudagrass (hybrid types)Bermudagrass (hybrid types)► Buffalograss (only native grass)Buffalograss (only native grass)► CarpetgrassCarpetgrass► CentipedegrassCentipedegrass► Seashore paspalumSeashore paspalum► St. Augustinegrass (sun)St. Augustinegrass (sun)► St. Augustinegrass (shade)St. Augustinegrass (shade)► ZoysiagrassZoysiagrass

First Spring First Spring ApplicationApplication

to warm season to warm season grasses about grasses about the time of last the time of last

frost!frost!

ZonesZones Last Spring Frost Begin Spring Nitrogen If Needed

11 No Freeze to Jan.30 Jan 30

22 Jan. 30 to Feb. 14 Feb 14

33 Feb. 14 to March 1 March 1

44 March 1 to March 16 March 16

55 March 16 to March 31 March 31

66 March 31 to April 15 April 1-15

77 April 15 to May 1 April 15-30

Last applicationLast application:: No later than 6 No later than 6

weeks prior to the weeks prior to the first fall freeze datefirst fall freeze date

ZonesZones First Fall Frost Late season ending point for Nitrogen

11 No freeze Nov 1

22 Dec. 16 to no freeze Nov 1

33 Dec. 1 to Dec. 16 Oct 15

44 Nov. 16 to Dec. 1 Oct 1

55 Nov. 1 to Nov. 15 Sept 15

66 Same as Zone 5 Sept 15

77 Oct. 15 to Nov. 1 Sept 1

Consider when, how often and how much in Consider when, how often and how much in putting together an annual nitrogen fertilizer putting together an annual nitrogen fertilizer

program for Texas lawnsprogram for Texas lawns

► Soil testSoil test in winter to determine in winter to determine need for complete need for complete (P, K, Ca, (P, K, Ca, Mg)Mg) fertilizers fertilizers

► ProjectProject a total amount of N to a total amount of N to apply per 1000 sq. ft/year. apply per 1000 sq. ft/year. see see table to follow…table to follow…

► Consider Consider use,climate, soil type use,climate, soil type and growing season and growing season Charts to Charts to follow…follow…

► Schedule N applications during Schedule N applications during the growing seasons:the growing seasons: timing & timing & rate in LBS per 1000 Sq Ft rate in LBS per 1000 Sq Ft

Annual Nitrogen Recommendations For Annual Nitrogen Recommendations For Texas LawnsTexas Lawns

Lawn Grass Type (species)

LBS Nitrogen per 1000 sq. ft per year

Warm Season Grasses Low Medium High

Bermudagrass (common type)

1-2 2-3 3-5

Bermudagrass (hybrid types)

2-3 3-4 4-6

Bahiagrass 1-2 2-3 3-4

Buffalograss 0-1 1-2 NR*

Carpetgrass 0-1 1-2 2-3

Centipedegrass 1/2 1 2

Seashore paspalum 1-2 2-3 3-4

St. Augustinegrass (sun) 1-2 2-3 3-4

St. Augustinegrass (shade) 1/2 to 1 1-2 2-3

Zoysiagrass 1-2 2-3 3-4

How oftenHow often should should fertilizer be fertilizer be

applied?applied?

How often should fertilizer be applied to Warm How often should fertilizer be applied to Warm season grasses?season grasses?

POST- GREENUP EARLYSEASON (ES)

NI TROGEN PERI OD

LATE GROWI NGSEASON (LS)

NI TROGEN PERI ODTexasZone

J an. Feb. Mar. Apr. May J un. J ul. Aug Sept Oct Nov Dec

1234567

SupplementalN

I f Needed

Using the chart on Annual Nitrogen Recommendations For Texas Lawns:Annual Nitrogen Recommendations For Texas Lawns:-It would be appropriate to apply low annual rates of nitrogen once in the spring, and -It would be appropriate to apply low annual rates of nitrogen once in the spring, and

if needed again in the fall. if needed again in the fall. -Split fertilizer applications are recommended. -Split fertilizer applications are recommended. -This may require 1 to 2 applications to apply 1 to 2 LBS of nitrogen per 1000 ft-This may require 1 to 2 applications to apply 1 to 2 LBS of nitrogen per 1000 ft22/year./year.-Medium and high annual applications will likely require additional applications during the-Medium and high annual applications will likely require additional applications during the

growing season. growing season. -Supplemental N if needed should be when rain is evident or irrigation can be supplied.-Supplemental N if needed should be when rain is evident or irrigation can be supplied..

What is this I hear What is this I hear about about environmental environmental issues (water)issues (water) and and

fertilizer application?fertilizer application?

Environmental Concerns in lawn fertilizationEnvironmental Concerns in lawn fertilization

► Nitrate leaching into groundwater

► Nitrate runoff in stormwater► Phosphorus stormwater

runoff into surface waters fate from over application,

poor timing, not using soil tests to determine need for phosphorus in your fertilizer

Take Home Message: When the grass plant is actively growing it is very effective in taking up nitrogen applied at reasonable rates!

AvoidAvoidMisapplication!Misapplication!

Keep fertilizer off hard Keep fertilizer off hard surfaces (reduces direct surfaces (reduces direct fertilizer runoff into fertilizer runoff into water resources)water resources)

Not a good thing for the lawn!