PLANT FERTILIZATION -- WINTERIZATION
After enduring summer drought
and the onslaught of foliage diseases, lawns have been through
more stress and adverse conditions than any of John Cameron
Swayze's Timex watches.
The first freeze (normally
after November 20) is quickly approaching and there are
a couple of important tasks to do now to insure the health
of your grass this winter. The most crucial is the fall
application of fertilizer. Many folks are scratching their
heads at this time of year wondering when to apply fall
fertilizer, what analysis to use, and how much to apply.
The important thing to remember is that the fall application
of fertilizer is the most critical. If you were given the
option of applying fertilizer only once a year to a lawn,
the best choice would be a fall application.
Fall fertilization is applied
when shoot growth slows or around the time of the season's
last regular mowing. Because of favorable environmental
conditions (cool temperatures, short days, and high light
intensity) nitrogen applied at this time aids the photosynthetic
production of carbohydrates. These carbohydrates are stored
for use the following growing season, providing earlier
spring green?up and an energy source for turfgrasses to
recuperate from stresses.
Another reason for fall fertilization
is to reduce the need for high amounts of spring?applied
nitrogen. Too much spring fertilization can actually reduce
carbohydrate reserves and root development by inciting rapid
shoot growth. This is because growing shoots take priority
over roots for carbohydrate use.
Both spring and summer fertilization
is used to maintain the color and density produced by fall
fertilization the previous year. Fertilization at these
times should not produce succulent plant tissue which can
increase the severity of turfgrass disease and reduce the
plant's ability to withstand heat, drought, mowing or wear
Most root growth in warm season
grasses ? such as bermuda, zoysia, and St. Augustine ? occurs
in spring and summer. Fertilization during these periods
stimulates root growth. The roots of bermudagrass and St.
Augustinegrass die in the spring following green?up. Heavy
fertilization in early spring may result in more stress
during this critical survival period.
What is the best kind of fertilizer
to use in the fall? For many years, high phosphorus fertilizers
(high middle number) were popular for fall use but through
research we now know that these can actually reduce winter
hardiness and impede spring recovery. Furthermore, in this
area of Texas, excessive applications of phosphorus will
tie up the iron and zinc in our soil and result in yellow,
The application of a complete
fertilizer which is high in nitrogen and potassium will
enhance fall lawn color (prolongs color retention) and promote
early green?up next spring, plus give added cold hardiness.
The actual phosphorus level should be lower than that of
the nitrogen and potassium. The best nutrient ratios for
fall fertilizer are 3?1?2 and 4?1?2. In the nursery you
will find these ratios in such fertilizers as 15?5?10, 16?4?8,
24?4?8, 12?4?10, 18?6?12, etc.
The fall application of fertilizer
should take place in mid?to?late October. The amount needed
is in terms of actual nitrogen to be applied. No more than
2 pounds of actual nitrogen per 1000 square feet should
be used. This equates to about 40 pounds of 15?5?10 on a
6000 square foot lawn.
The slow release nitrogen
fertilizers are as beneficial in the fall since a quick
uptake by the plants is important. In the fall we want the
nitrogen to be available to the grass quickly so that it
can be taken up into the plant and utilized. Besides, slow-release
fertilizers are much more expensive because of their slow-release
The second task that is a
must to insure a healthy turf is controlling brownpatch.
Brownpatch is a fungus disease that attacks St. Augustine
grass in cool, damp, fall weather and will weaken the lawn
going into the winter. It is identified as a circular area
in the lawn, usually 3?10 feet in diameter. In the edge
of the area you will see browning or yellowing grass, yet
the interior of the circle may be a healthier green. Pull
blades of grass at the edge of the circle. If the blades
pull easily away from the stems and look brown and rotted
at the base of the blades, then your lawn does have brownpatch
and should be treated. The most economical and effective
chemical control for brownpatch is terraclor ? PCNB (ex.
Turfcide, Fertilome ? Lawn Disease Control).
To help prevent brownpatch
from getting started in the lawn, do not water in the evening.
Water droplets that stay on the grass all night will spread
the brownpatch spores. Therefore, water in the early morning
hours so that the grass will dry out during the day and
before nightfall. Once you have brownpatch, do not walk
through or mow through contaminated areas when wet so that
further spreading will not occur.
One other important chore
in the lawn and entire landscape to prevent winter damage
is watering thoroughly during the winter. Although the top
of plants may go dormant during the winter, the root system
does not and needs moisture to continue growth. Also, it
is fact that a well watered plant is less likely to suffer
freeze damage then a drought stressed plant. So get out
there this winter and water that landscape at least once
a month in lieu of rainfall.
Fall fertilization, controlling
brownpatch and watering will insure that our lawns will
be well on their way to a healthy next season
Tree and shrub health is important
and fertilization at the proper times insure tree and shrub
health. I also recommend that you take the time this fall
to fertilize your trees and shrubs using the same Winterizer
fertilizer which is recommended for grasses. During the
fall period of maximum rainfall, plants absorb nutrients
more effectively. Summer and winter are not optimum times
to fertilize. Hot temperatures cause the soil to become
dry and compacted; in cold weather, plants are dormant,
and the soil is not workable.
In the forest, trees draw
nutrition from a steady supply of organic plant and animal
matter such as decomposed leaves. This layer of matter covering
the forest floor acts as a fertilizer. Like mulch, it helps
the ground hold moisture and maintain moderate temperatures.
But in tidy backyards and
other landscaped areas, this nutrient?rich layering process
doesn't often take place. Instead, the ground is covered
with lawn, which must compete with trees and other plants
for nutrients and water. Construction and other land?use
projects may alter the soil by adding pollutants and rubble
Without the balanced natural
environment, even vigorous, specimens may have some trouble.
Because a plant's well?being depends on its ability to grow,
the health of the root system is crucial. Roots must keep
drawing sufficient nutrients and water to sustain growth.
But as they continue to grow, at some point they'll run
into restrictions such as paving, structures, rocks, rubble,
roots of other plants, and hard, compacted soil. under such
conditions they may not be able to absorb nutrients and
water as easily as before. The results: less new growth,
pale color, and damage due to insect attacks and disease.
To overcome these growth inhibitors, trees and shrubs need
good care and maintenance.
Timing??knowing when to fertilize??is
vital to top?quality plant care. It's important to fertilize
plants at or during a certain time so the tissues of the
new growth will toughen sufficiently to weather the first
freezes. Without this "hardening?off" and easing
into dormancy, the plant can be severely damaged by winter
stress. Proper timing will help you promote dormancy early
enough to prevent such damage.
Fertilization keeps trees
and shrubs from falling victim to health problems such as
previously mentioned decay. Resilient limbs and general
vigor make them sturdy enough to weather storms and extreme
temperatures. And the healthier they are, the more beautiful