OC414
$0.20
Michigan State University ExtensionOakland County
Fertilizing Fruit
Trees
We are frequently asked what is the best fertilizer to use on tree fruits and when is the
best time to apply fertilizers.
ings. Stone fruits are generally grown on
light soils and are therefore more likely to be
deficient in potassium than apple or pears.
It is safe to say that all plant materials utilize
the following elements in one form or another and at varying rates: nitrogen, phosphorus, potassium, magnesium, calcium, zinc,
manganese, iron, copper, boron, aluminum,
and molybdenum.
Of these, nitrogen,
phosphorus, and potassium are the most
important with nitrogen frequently being the
only fertilizer element required on an annual
basis for fruit trees.
Fertilizers should be applied in late fall or in
the early spring. Late fertilizer applications
(after mid-June) encourage vigorous terminal growth which may inhibit hardening off in
the fall with subsequent winter damage to
fruit trees under extreme low temperatures.
Apply fertilizers in a band around the drip
line (outer most spread of the branches) of
trees. As trees age, the drip line expands.
While fruit trees have a wide tolerance to soil
acidity, the application of dolomitic limestone
will correct both calcium and magnesium deficiencies if soil tests or leaf analysis reveals
that such an application is warranted. Don’t
apply lime without having the soil tested.
Fertilizer applications should be based upon a
knowledge of the fruit’s nutrient needs as it
relates to terminal growth and soils in which
the fruit is being grown. A good general
“rule of thumb” is that peach trees should
make about 12-18” of annual growth and
that apple trees about 8-12” of annual
growth. Any amounts less than this indicates that the tree is not receiving sufficient
amounts of nitrogen, and that nitrogen applications should be increased.
Greater
amounts of annual new growth indicate that
too much fertilizer has been applied or that
the soil is very “rich” in nitrogen.
Potassium is second only to nitrogen in nutritional requirements for Michigan fruit plant-
Fertilization applications are not recommended the year that young fruit trees are planted.
A general guide for the application of nitrogen, phosphorus, and potassium follows:
Nitrogen
Nitrogen needs may be met by use of one
the following three forms:
1. Ammonium Nitrate (33-0-0), 3lbs. Of Ammonium Nitrate equals 1 lb. actual nitrogen
2. Ammonium Sulfate (20-01-0), 5 lbs. of
Ammonium Sulfate equals 1lb. Actual nitrogen
3. Urea (45-0-0), requires slightly more
than 2lbs. Of either of these carriers to
equal 1lb. Of nitrogen
Apply nitrogen to young fruit trees at a rate
of 1/4-1/2 lb. of actual nitrogen per tree per
year of age. Young trees should produce
more new growth than older trees, 24-30” of
growth is desirable on 1 and 2 year old trees.
Increase or decrease the amount applied of
nitrogen applied to obtain the desired
amount of growth.
except nitrogen, need not be repeated annually. It is easier to increase than decrease
nitrogen levels, so base nitrogen fertilizer applications on previous year’s growth rate,
fruit size and color and soil type in which
trees are grown.
Mature apple and pear trees should receive
between 1-2 lbs. of actual nitrogen annually
depending upon whether they are semidwarf or standered type trees.
Manures are also a good source of nutrients
when applied at recommended rates to plant
materials. However, the nutrient values of
manures do vary widely making it difficult to
actually state the exact nutrient composition.
Not all of the value of manures is in the nutrients elements, as the organic matter is also important when considering the improvement of soil structure. Generally speaking,
about 50% of the nitrogen and phosphorus
are available to fruit crops the first year of
manure application while potassium is considered to be 100% available. The general
nutrient composition of manures is approximately 14-8-13 in terms of N-P-K.
Mature cherry, plum and peach trees should
recive between 3/4-1 lb. of actual nitrogen
annually.
Phosphorous
Superphosphate (0-45-0) is perhaps the best
and easiest material to use to meet phosphorous requirements of tree fruits. Apply between 8-10 lbs. of superphosphate per tree.
Phosphorous deficiencies are not a common
problem under Michigan conditions.
Potassium
Potassium deficiencies are second only to nitrogen in Michigan. This is due to the fact
that many Michigan soils where fruits are
raised are light textured. Muriate of Potash
(KCL)(0-0-60) is readily available and may
be used at the rate of 3-6 lbs. per tree.
Manure containing bedding will generally
have a higher nutrient content and is desirable to use in fruit crop production. Manure
mixed with bedding or straw may be applied
around the base of a tree extending out to
the drip line to a depth of 5-6”. The best
time to apply the manure would be in late
fall or very early spring.
Keep in mind that most fertilizer applications,
Would you like additional information?
Additional information is available on-line. Please see MSU Extension-Oakland
County’s publications as well as the MSU Extension Bookstore on campus.
Please contact our office (248/858-0880) for assistance.
Distributed by MSU Extension-Oakland County, 1200 N. Telegraph Road, Pontiac, MI 48341,
248/858-0880, www.msue.msu.edu/oakland. Reviewed by Charlene Molnar, Horticulture Advisor,
May 2012.
MSU is an affirmative-action equal opportunity employer. Michigan State University Extension programs and materials are open to all without regard to race, color, national origin, gender, gender
identity, religion, age, height, weight, disability, political beliefs, sexual orientation, marital status,
family status or veteran status.