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by Rett Davis | |
Gardening Q&A by Rett Davis appears in
Alamance County's daily newspaper, The Times-News,
every Sunday in the Accent section. Each week's installment is
posted to this
website, beginning with January of this year. Scroll to the bottom of
this page to navigate to other Gardening Q&As. Please contact
Rett via e-mail with questions
or
comments in regard to this column.
Question:
Almost overnight my fescue lawn has developed brown patches in
it. It seems to have spread over the entire lawn. What is this and
what can I spray to stop it?
Answer:
It seems as though we go from one turf disease to another in a
matter of one week. Now that temperatures and the humidity are climbing
the presence of summertime diseases appears. This disease is actually
called 'brown patch' for obvious reasons. This hotfoot weather disease
appears when daytime temperatures are above 85 degrees and night
temperature exceed 60 degrees. Brown patch is a fungal disease and will
remain active until late August. Brown patch will always be worse after
a cool wet spring. This is why it so wide spread in almost every fescue
lawn. No fescue culitvar is immune to this disease. Poor soil
drainage, lack of air circulation, cloudy weather, heavy dews, over
watering, and watering in the late afternoon favors the spread of this
disease and it's severity. In addition, high rates of nitrogen applied
late in the spring adds to the susceptibility of this disease. All of
the above conditions have been present this year. It is no wonder the
problem is so bad. Professional lawn care companies do have in their
arsenal several fungicides such as Compass, Bayleton, Heritage, and
various brands of chlorothalonil that can cure and halt the spread of
this disease. They must spray your lawn at least twice to reign this
disease in. Homeowners can use mancozeb products and products
containing chlorothalonil (Daconil 2787) to slow this disease down.
Read label directions for spraying frequencies and precautions. If you
elect to do nothing, you lawn will survive if you mow when the grass is
dry, the mowing height is 3 to 4 inches, and you do not irrigate in the
afternoon or evening. You must also except a less than perfect green
lawn with brown leaves intermingled within the green. Fall
fertilization will restore the lawn to its former beauty.
Question:
How often should I have my lawn mower blade sharpened?
Answer:
This somewhat simple question really is important to the health
of turf grass. A dull blade will shred and tear grass leaving the ends
frayed and damaged. This will lead to higher rates of disease
infection. Therefore a shape blade is part of an overall disease
management program. Professional mowers will sharpen their blades
monthly if not weekly. Homeowners need to sharpen their lawn mower
blade at least twice a year. I sharpen mine at the beginning of spring
and again in late summer. Unless you are mowing over rocks, sticks, and
brush this should be suffice. You can sharpen your own blade with a
flat file or grinding wheel. Almost all hardware stores and lawn mower
repair shops sharpen blades. It is very inexpensive and very important.
Question:
Why are the leaves on all my dogwoods turning gray? Is this
harmful?
Answer:
This is powdery mildew. It is a fungus that grows on the
surface of the leaves. The infection will cause distorted leaves and
dwarf newly emerging leaves. There are numerous species of powdery
mildew that infect our favorite perennials, ornamental shrubs, and fruit
trees. Older mature dogwoods do not require treatment. Newly planted
dogwoods and young trees can be helped with a spraying of Immunox every
10-14 day throughout the summer.
Question:
I have noticed some strange behavior of some small maggot
like insects crossing my driveway. They are all lined up touching one
another moving in a line as if they were connected. What kind of
insects are they?
Answer:
You are witnessing the larva of the dark winged fungus gnats.
They actually do travel together in a string like fashion. Fungus gnats
breed and feed in wet soils and organic matter. They feed on fungi in
the soil. The adult fungus gnats will gather on the shady sides of
homes and mass together. They can enter you through your screens and
are often mistaken for mosquitoes. Gnats are not mosquitoes and will
not bite or harm you. Just another curiosity of nature. Consider
yourself lucky and among the few that have witnessed this event.
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If you have any horticultural questions, please direct them to Rett Davis