Example of How to Determine How Much Fertilizer to Use

Step 1: Calculate the Area of the Property

This is what a typical home landscape basemap may look like:

1.) Break the property into easily measurable pieces.

Large rectangle:

67' X 130'

=

8,710 ft^2

Triangle:

130'	45'		87'
-85'	-25'		-67'
45'	20'	= Leg 1	20'	= Leg 2

½ (20' X 20')

=

200 ft^2

Small "square":

20' X 25'

=

500 ft^2

2.) Add the pieces together.

8,710 ft^2
+200 ft^2
+500 ft^2
9,410 ft^2	E This is the total area of the property.

This is what a typical home landscape may look like:

Step 2: Calculate the Area of All Areas Not Covered by Lawn

1.) Measure the area (Length X Width) of all spaces not covered by lawn.

See column one and two of table.

2.) Add those totals together.

See column three of table.

Step 3: Figure the Area of Lawn to be Covered With Fertilizer

Subtract the area of the property from the area not to be covered by lawn:

Property	è	9,410.0 ft^2
Not Covered by Lawn	è	-4,857.5 ft^2
		4,552.5 ft^2	=	4,550 ft^2

Therefore, I have 4,550 square feet of lawn to fertilize.

Since all University recommendations are per 1,000 square feet, I need to multiply the recommendation by 4.5.

4,550	=	4.5
1,000

Step 4: Calculate the Amount of Fertilizer Needed

How much N should I use to maintain this lawn?

(How much fertilizer do I need to add 1 pound of actual Nitrogen to my lawn?)

Lawn size	=	4,550 ft^2
Fertilizer formulation	=	24-2-12
Application rate	=	1 pound of actual N per 1000 ft^2

formula:

Total Fertilizer needed =	N application rate in lb/1000 ft^2	X	Lawn size in ft^2
	N content of fertilizer as a decimal		1000

solve:

1	X	4,550	=	4.55	=	18.96 lb of 24-2-12
.24		1,000		.24

Return to Bay-Wise Program Homepage