June 2015
To promote optimal growth and production of your citrus tree,
use the chart to determine the correct amount of fertilizer to apply.
Steps To Use This Fertilizer Chart:
1 . On the left edge of the chart, find a description of the
tree you wish to fertilize. Since commercial citrus fertilizer
application recommendations are based either on tree height,
trunk diameter or the area of the ground covered by the
canopy, ranges of all three measurements are included in
the tree descriptions. The total pounds of actual nitrogen
recommended by the University of Arizona for a tree for one
year are found in the column directly to the right. Since
no fertilizer is 100% nitrogen, use the chart to determine the
amount of a specific type of fertilizer needed by your citrus
tree.
2. Look at the top edge of the chart for the percent
nitrogen which your fertilizer contains. Remember that
every container of fertilizer has 3 numbers written on it.
The first number indicates the % nitrogen, the second the %
phosphorus as available phosphate (P2O5), and the third the
% potassium as available potash (K2O). For example: 9-6-4
has 9% nitrogen, 6% phosphorus and 4% potassium – see
illustration.
3. The intersection of the row describing your tree, and the
column indicating % nitrogen of your fertilizer, is the
recommended range of pounds of that particular type of
fertilizer to use during the entire year for oranges, tangerines
and other exotic citrus. For grapefruit and pummelo, apply
½ of this amount annually, and for lemons and limes, apply
about 10% more than the amount in the chart annually.
4. For oranges, tangerines, and grapefruit, apply ⅓ of the
recommended range of fertilizer in January-February, ⅓ in
March-April and ⅓ in May-June.
5. For lemons and limes, apply ⅓ of the recommended range
of fertilizer in January-February, ⅓ in March-April and ⅓ in
August-September.
Example 1:
You have a small, 2-foot tall lemon tree, and a bag of citrus
food (13-10-4) which has 13% nitrogen. Find the row for a
az1671
Citrus Fertilization Chart for Arizona
Glenn Wright
Fertilizer does no good in a heap, but a little spread
around works miracles all over.
-Richard Brinsley Sheridan - Irish Playwright
Steps at a Glance
1. Select the row from the chart which most closely describes your
tree.
2.Select the chart column that matches the first number on your
fertilizer product (the percent nitrogen of the fertilizer).
3. The box where the row and column intersect is the recommended
range of fertilizer to apply annually. Grapefruit will require 50% less,
and lemons 10% more than this amount.
4. For oranges, tangerines, and grapefruit, apply ⅓ of the total
fertilizer from Step 3 in January-February, ⅓ in March-April and ⅓
in May-June.
5. For lemons and limes, apply ⅓ of the total from Step 3 in January-
February, ⅓ in March-April and ⅓ in August-September.
Illustration Credit: Christiana Wright.
small tree. Then, find the
column for 13% nitrogen.
They meet at the number
1.9 to 3.8. Because the tree
is a lemon, add about 10%
to the total (2.10 to 4.2
lbs.). Since the tree height
is at the low end of the
range, apply 2.10 lbs. of the
citrus food during the year.
Apply ⅓ (about 0.7 lbs.)
during January-February,
⅓ in March-April, and ⅓ in
August-September.
Example 2:
You have a large, 10 foot tall adult grapefruit tree, whose canopy
covers about 100 square feet of the ground surface and you have
citrus fertilizer with 6 % nitrogen (6 is the first of the three numbers
on the bag). The row for this tree and the column for 6% nitrogen
join at the numbers 20.80 to 25.00. Mature grapefruit trees require
only half of the amounts listed in the table.
Therefore, this tree will require about 10.4 to 12.50 lbs. of
fertilizer annually. Apply about 3.5 to 4.0 lbs. (⅓ of the total)
during January- February, ⅓ in March-April and ⅓ in May-June.
Adapted from and replaces
Chott, G., Chard, C., Bradley, L., 1998. Fetilizing Citrus Chart.
University of Arizona Bulletin MC91. Tucson, AZ.
2The University of Arizona Cooperative Extension
Oranges, tangerines, tangelos,
and other exotic citrus. For
grapefruit, pummelo, lemons
and limes, see note below.
Lbs. of
Actual
Nitrogen
Required
for the Year
% N in Fertilizer
(F number written on fertilizer container – See illustration)
4% 5% 6% 8% 10% 13% 16%
21%*
(A
S )
46%*
(U )
N Planted T
Y may apply of
after tree is established and
growth has emerged
None to
0.13 lb.
None to
3.0 lbs.
None to
2.5 lbs.
None to
2.0 lbs.
None to
1.5 lbs.
None to
1.2 lbs.
None to
0.9 lb.
None to
0.75 lb.
None to
0.6 lb.
None to
0.25 lb.
S T
2 3 feet tall, up to 1.25” trunk
and up to 9 sq. ft. of
area covered by the canopy
0.25 to 0.50
lb.
6.25 to
12.50
lbs.
5.00 to
10.00
lbs.
4.20 to
8.40 lbs.
3.10 to
6.25 lbs.
2.50 to
5.00 lbs.
1.90 to
3.80 lbs.
1.60 to
3.20 lbs.
1.20 to
2.40 lbs.
0.50 to
1.10 lbs.
M T **
4 8 feet tall, 1.25” to 4.0” trunk
and from 16 to 64 sq. ft. of
area covered by the canopy
0.75 to 1.00
lb.
18.75 to
25.00
lbs.
15.00 to
20.00
lbs.
12.50 to
16.75
lbs.
9.40 to
12.50
lbs.
7.50 to
10.00
lbs.
5.80 to
7.70 lbs.
4.70 to
6.50 lbs.
3.60 to
4.80 lbs.
1.60 to
2.20 lbs.
L T
10 tall or more, 6 to 10” trunk
and more than 64 sq. ft. of
area covered by the canopy
1.25 to 1.50
lbs.
31.25 to
37.50
lbs.
25.00 to
30.00
lbs.
20.80 to
25.00
lbs.
15.60 to
18.75
lbs.
12.50 to
15.00
lbs.
9.60 to
11.50
lbs.
7.80 to
9.40 lbs.
6.00 to
7.10 lbs.
2.70 to
3.30 lbs.
Annual Fertilizer Requirements for Citrus Trees
• Fororanges,tangerines,andgrapefruit,apply
⅓
of the total in January-February,
⅓
in March-April and
⅓
in May-June.
• Forlemonsandlimes,apply
⅓
of the total in January-February,
⅓
in March-April and
⅓
in August-September.
Note: For grapefruit and pummelo trees small adult or larger: use ½ of the amounts shown. For lemons and limes, use about 10% more than the amounts shown.
* Application of 21-0-0 or 46-0-0 fertilizer will require additional applications of other nutrients, as
these fertilizers only contain nitrogen. Urea (46-0-0) is especially concentrated.
** Trees in containers should be fertilized according to this chart, but usually grow no taller than a
medium-sized tree.
• Toconvertfromdecimaltoounces,multiplythedecimalportionofthenumberby16.Example:
For 6.25 lbs. fertilizer, multiply .25 x 16 = 4 ounces, giving 6 lbs. 4 oz.
• Measureaccuratelybeforeapplyingandalwaysincorporatefertilizersinthesoilandfollowwith
irrigation.
3
The University of Arizona Cooperative Extension
The UniversiTy of ArizonA
College of AgriCUlTUre And life sCienCes
TUCson, ArizonA 85721
glenn WrighT
Associate Extension Specialist – Citrus and Date Palms
ConTACT:
glenn WrighT
This information has been reviewed by University faculty.
extension.arizona.edu/pubs/az1671-2015.pdf
Originally published: 1998
Other titles from Arizona Cooperative Extension can be found at:
extension.arizona.edu/pubs
COLLEGE OF AGRICULTURE & LIFE SCIENCES
Cooperative
Extension
Any products, services or organizations that are mentioned, shown or indirectly implied in this publication
do not imply endorsement by The University of Arizona.
Issued in furtherance of Cooperative Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, Jeffrey C. Silvertooth,
Associate Dean & Director, Extension & Economic Development, College of Agriculture Life Sciences, The University of Arizona.
The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin,
age, disability, veteran status, or sexual orientation in its programs and activities.
