Johnsons's Garden Centers Text File document - copyright 2002
PDF file available at http://www.johnsonsgarden.com/newsletter/fertilizer.html
PDF file available at http://www.johnsonsgarden.com/newsletter/nurseryplants.html

Johnson's Nursery News ... Time to Feed Trees and Shrubs
October 2002
Jeremy Johnson, Johnson's Nursery Buyer, Kansas Certified Nurseryman

    Trees and shrubs ... like humans ... require nutrients to live and
thrive. When these plants are not given proper nutrition, they are
susceptible to insect and disease problems, and do not grow as they
normally should. Proper fertilization of landscape plants can actually
help to fight off many problems before they arise.

    Fall is the ideal time for fertilization of our landscape plants.
This theory goes back hundreds of years to when the plants lived in the
wild. In the fall, when deciduous trees lost their leaves, the leaves
were broken down on the forest floor, providing beneficial nutrients to
the root systems of the trees. Since we are not able to replicate
nature's forest setting on our own landscapes, we must add supplemental
nutrients.

    To begin looking at fertilization, we need to do a little thinking
first. Tree roots spread minimally to the "dripline" (edge of the
branches) of the plant, and can actually spread 2-3 times this width in
an established plant. Many people also think that tree roots only go
straight down, as in a tap root. This tap root helps to anchor the tree,
but the majority of feeder roots are actually in the top 18" of soil
under the base of the tree extending outward towards (and sometimes
past) the dripline. Now that the basic science lesson is over, we can
look at fertilizing our plants. There are many different methods of
fertilizing trees and shrubs, some providing more benefit than others.
At Johnson's, we carry several easy-to-apply fertilizers for landscape
plants.

    One good method, if applied properly, of getting fertilizer to the
roots of the tree is by using a root feeder. You are probably familiar
with the spike that is attached to a hose, with food tablets inserted
inside. The food in this case is a water soluble tablet that deep-feeds
the roots of the tree. One caution is to make sure you use this
application method under the drip line as instructed on the package. You
will need to use quite a few holes to fertilize a large tree, so this
method, while seemingly easy at first, can become a daunting task once
you start.

    Another popular method is tree spikes. These are about 6" solid
fertilizer stakes that are hammered into the ground around a tree. Based
on the little lesson above, we know that roots extend from the plant in
no particular fashion, so by using one of these, you may not be getting
the proper fertilizer to your plants. While these can be an OK choice in
some cases, large trees often require many stakes to provide the right
amount of fertilizer.

    My favorite, and by far the easiest, way to fertilize is with
granular ferti-lome Tree & Shrub Food. This product is applied by
filling a broadcast spreader with food, and simply walking around the
base and dripline of the tree. Tree & Shrub Food has an added wetting
agent so the food is carried deep into the soil, reaching the feeder
roots of the tree. Once all of the food has been applied (which can be
done by hand as well), you simply water everything in.

  Whether you have never fertilized, or do it religiously every year,
now is the time to get it done. If you have any other questions, our
staff at all three stores will be very happy to assist you, or you can
e-mail me at jeremyj@johnsonsgarden.com.