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If you
have Japanese beetles, you may want to do something; they'll be back
Japanese
beetle update, evergreen pruning and yellow grass
By John
Fulton
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[July 02, 2007]
The numbers of adults have been
impressive in some cases. Trees, shrubs, vegetable plants, and fruit
plants and trees have all been affected. Of course there are some
plants that are favored feeding sites. These would include Japanese
maple, Norway maple, horse-chestnut, hollyhock, flowering crab
apple, apple, cherry, peach, rose, mountain ash, linden and grape.
There are other plants that are seldom attacked, such as red maple,
silver maple, boxwood, flowering dogwood, euonymus, ash, oak and
lilac. Of course, you need to take this list with a grain of salt,
since I have sprayed large numbers of beetles on the seldom-attacked
plants this weekend.
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 My rule of thumb is to protect fruits, vegetables, valuable
ornamentals and new transplants. Most are spraying Orthene,
Sevin, permethrin or bifenthrin. The frequency is what gets us
sometimes, with sprays needed at least every week in most cases.
To dispel a common myth, once you have the beetles you will
always have them. They do not occur on an infrequent basis like
periodical cicadas, nor is it "just a year to have them." They
have expanded their range, and you are now in it.Pruning
evergreens
This is the time of year to wrap up pruning chores on
evergreens. This includes both needle-type and broadleaf
evergreens. If you're wondering what a broadleaf evergreen is,
that includes holly, rhododendron and azalea. The logic behind
pruning your yews at this time is to allow sufficient time for
regrowth to become hardened off before winter and to keep new
growth from becoming too rank before the winter months.
Pruning evergreens is part art and part science, but mostly
art. A few simple rules to follow make the job results much more
pleasing. Upright growing evergreens, such as pines and spruces,
should not have the main leader cut off. This will destroy the
natural shape and will make the resulting growth more
susceptible to breaking off. If individual branches are being
cut off, they should be cut back to a bud. This will allow the
bud to become the new main branch. You can also control growth
direction of branches in this way. If you are growing trees for
cut Christmas trees, all bets are off, as you are dealing with
trees only through the first seven years of their life or so.
Make sure you use the proper equipment. Individual pruning
cuts are best done with bypass loppers or pruning shears. These
make clean cuts without much damage to the remaining wood. The
old anvil-type shears and loppers cut to a point, then crush the
remaining wood. For yews, junipers and arborvitae that are
trained to a certain size or shape, you will want to use hedge
shears (electric or manual) that are sharp and properly
tightened. Most of these types of shears can cut up to about a
quarter of an inch in size.
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 When pruning evergreens, remember the dead zone. This is the area
toward the center of the plant that doesn't receive much light. It
also has few needles or active buds. Cutting into the dead zone will
cause many years (or forever) of little green growth. Also, remember
to prune so that the base of plants is wider that the top. This
allows sunlight to hit the bottom area as well and keeps the bottom
from dieing up.
Yellow grass
There seem to be many yellow patches of grass showing up in area
lawns. Large amounts of rain could have pushed nitrogen below the
level where grass roots can reach it, or the rain can lead to
denitrification, when the bacteria in the soil break down nitrate
forms of nitrogen for the oxygen they contain. Any root damage also
reduces the amount of nitrogen and other elements that can be taken
up into plants. Grubs of any sort, including Japanese beetle larvae,
feed on plant roots. Add to this the fact that many of the yellow
spots are in the area of tree roots. Trees compete for the same
moisture and nutrients as grass areas, and trees are more efficient
at getting these nutrients.
The long and short of it is that yellow grass areas are probably
going to be with us for most of the season. Adding additional
nitrogen now is not recommended unless you are on a frequent
watering schedule. Even then, you probably won't green it up any
time soon. The yellow is not that efficient a pigment for making
food, so those areas will be a little less healthy than others. Try
to mow at recommended heights of 2 to 2.5 inches, fertilize in early
September and water at least a quarter of an inch per month if
things stay dry for a month.
[Text from file received from
John
Fulton, University of Illinois Extension,
Logan County Unit] |
