Thursday, October 02, 2008
New herbicide unlikely to help in Roanoke area
John Arbogast
Landscape consultant John Arbogast answers your questions every Thursday. Send questions about your lawn, garden, plants, or insects to:
Dear John
5102 Greenfield St. SW
Roanoke, Va. 24018
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Q: Have you tried the new herbicide made by Bayer and sold at Lowes? It is supposed to kill Bermudagrass with repeated use, and not kill at least Fescue and bluegrass. This kind of product is what many of us here in the mid-Atlantic states need. Even if you haven’t tried it yet, I’d like your comments.
A: No, I have not tried this new herbicide, even though I must admit that I do have a little bit of wild Bermudagrass (wiregrass) in my fescue and bluegrass lawn. The Lowe’s closest to me does not carry it, and the Web site for this herbicide made by Bayer has so much security built into it that I was not able to copy the chemical’s legal document better known as the chemical’s “label.”
Comments that I heard made me think that this might be one of those home herbicides that have to be used precisely as directed on the label, especially the part that says that no more than a certain amount should be used per 100 square feet of lawn area per application or else yellowing or death of bluegrasses and fescues will occur too. The “ready-to-spray” version of this herbicide is designed to be attached to the end of a garden hose. Some of us walk quickly with a running hose thus applying a lower amount of active ingredient per area than those of us who walk slowly with a hose and thereby apply more active ingredient per the same area.
In the “For Best Results ” section of the label, under “When to Apply ” section, the comment to spray when the grass weeds are small and actively growing tells us to begin applications during the spring “green-up time.” The label suggests “continue monthly use for 1 to 2 growing seasons.” and “spray when the temperature is below 90 degrees.” That could make the process time consuming, expensive, and potentially impossible for use by Roanokers to spray during typically hot summer months.
Q: Could the dry years that parts of the eastern states have had be responsible for dying of many Flowering Dogwoods or is their dying due to the fatal dogwood disease that was in the news a few years ago. I live in Virginia.
A: In Roanoke, I believe that Flowering Dogwoods have been dying at a higher-than-normal rate recently as a result of prolonged months of below normal precipitation that we’ve had in recent years and the related reduction in the lowering of the “water table” causing enhanced stress on these trees.
The fatal disease that was in the news a few years ago predicting the demise of many flowering Dogwoods is called Discula Anthracnose. The Discula fungus that causes this fatal infection likes cool, damp environments to thrive in. It has been more of a Flowering Dogwood problem in cooler environments such as in higher elevations and in damp environments such as in natural plantings in crowded forest.
