| Beverly Shaw
Question and Answer
Q. In the June column, Beverly
Shaw's response to "Thicket thinning" really piqued my interest.
"Gardening Q&A" has probably at some time in the past dealt
with the problem; nevertheless, I was disappointed that she did not elaborate
on how one "selectively" or otherwise "removes" such
things as honeysuckle and multiflora rose. Perhaps a future column can
revisit ways of doing (or trying to do) this. (Also briars; poison ivy;
I probably give up on.)
Late in January this year, we had a severe
freeze, -14 F. Honeysuckle seemed to take it hard, so I hoped its growth
might be retarded. It, with the help of the birds, had been threatening
to take over my entire acre. Unhappily, it has rebounded with a vengeance
this spring and will soon suffocate us all, plants, trees and maybe humans,
if severe counter-measures are not taken. Help! -- Richard L. Lippke,
Floyds Knobs, Ind.
A. Indeed, four species of honeysuckle and the multiflora
rose are considered invasive plants of Indiana. An invasive plant is one
that grows quickly and aggressively, displacing other plants as it spreads.
Usually, those plants labeled as invasive by the Indiana Department of
Natural Resources are not native to North America. Invasive plants hurt
wildlife by eliminating the plants our native animals need for food and
cover, and destroy habitat for rare wildflowers and animals.
The Nature Conservancy Web site gives the
following control recommendations for exotic bush honeysuckle species:
"Mechanical controls include grubbing or pulling seedlings and mature
shrubs, and repeated clipping of shrubs. Effective mechanical management
requires a commitment to repeated treatments for a period of three to
five years. Winter clipping should be avoided as it encourages vigorous
re-sprouting. Repeated annual prescribed burns during the growing season
will top-kill shrubs and inhibit new shoot production. Because exotic
bush honeysuckles readily resprout, it may be necessary to re-burn every
year or every other year for several years. Most managers report that
treatment with herbicides is necessary to control the exotic bush honeysuckles.
Water-soluble formulations of glyphosate (brand names Roundup, and for
use near waterbodies, Rodeo), a non-selective herbicide, and formulations
of triclopyr (brand names Garlon, Pathfinder, and others), a selective
herbicide for broad-leaved plants, have been used as foliar sprays or
cut stump sprays and paints with varying degrees of success. Both glyphosate
and triclopyr should be applied to the foliage late in the growing season,
and to cut-stumps from late summer through the dormant season. The flush
of seedlings that sometimes follows herbicide treatments must also be
controlled. For more information, go to http://tncweeds.ucdavis.edu/esadocs.html.
There you will find recommended controls for many weeds.
Personally, I physically remove some shrubs
and spray others with glyphosate, but it does take repeated applications
to truly kill the plant.
Multiflora rose can be controlled by removing
the plant (and the use of a bulldozer is recommended in some studies),
repeated mowing if the rose is in a grassy area or cutting followed by
a 1 percent glyphosate application on the cut stems. Glyphosate sprayed
on the leaves and stems will need to be repeated throughout a growing
season to kill the plant.
Q. The very first Japanese
beetles have shown up and they drive me crazy. I found them burrowed in
the blossoms of my shrub roses, but I know they'll be everywhere soon.
I know not to use traps, but what's the best way to control them? -- Ruby
Miller, Muncie, Ind.
A. Japanese beetle larvae
develop underground and emerge in late June or early July as adult beetles.
They feed upon many plants.
Control a mild infestation by picking them
off and dropping them in a bucket of soapy water. Severe infestations
require the application of an appropriate insecticide, including cyfluthin
(sold as Tempo or Bayer Lawn and Garden), malathion, carbaryl (Sevin)
or permethrin (Spectracide), among others. To protect ornamentals against
the feeding of adult Japanese beetle, leaves should be coated with insecticide
during the adult flight period. Typically, this may entail two treatments
during the peak beetle flight. Homeowners should make their first application
when damage is becoming intolerable and beetles are still abundant. The
need for repeated applications can be curtailed by inspecting plants for
additional beetle damage prior to applying a second treatment.
For more information, ask the Purdue Extension
office in your county for "Japanese Beetles in the Urban Landscape"
(E-75-W) or find it online at http://www.entm.purdue.edu/Entomology/ext/targets/e-series/EseriesPDF/E-75.pdf.