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Coping
with Field Bindweed without Using Herbicides
PDF
version
Field bindweed
is more than a nuisance; it's a pernicious weed. Like many nonnative invasives,
bindweed is a tough plant that threatens to take over once it gets a toehold.
Its cosmopolitan presence in many temperate climates has earned it 84 names
in 29 different languages—most of those names are not kind.(1) There aren't
many positive things to say about a plant that can smother a garden in
a season and reappear Terminator-like after the most conscientious yanking.
However, bindweed can be managed and even eliminated if you are persistent.
History
Field bindweed's Latin name, Convolvulus arvensis describes the plant
well, being derived from convolere, “to entwine,” and arvensis, “of the fields.”(2)
It also goes by the common names wild morning glory, creeping jenny, creeping
charlie, cornbind, greenvine, and lovevine.(3) Not to be confused with the
annual ornamental morning glory (Ipomoea spp.), field bindweed is
an aggressive perennial weed.(3,4)
Bindweed, a native of Eurasia, was sold as an ornamental
in the U.S. in the early 1800s. It was firmly established in the West by
the end of that century.(1)
Description
Bindweed's leaves are arrowhead shaped and about 1/2 to 2 inches long.(6)
The mature leaves at the base of the plant are the largest, while the young
leaves are progressively smaller towards the end of the stem.(6)
Bindweed has an extensive, deep network of roots and rhizomes (underground
stems) enabling it to strongly compete with other plants for water. The
roots are white, cord-like, and brittle. Horizontal creeping roots produce
buds and new shoots.(3)
The
flowers are funnel-shaped, about an inch wide and range in color from white
to pink.(7)
Bindweed favors heavy soils.(5)
Prevention
Keeping bindweed out of your fields or garden is the best way to prevent
problems with this weed.
Since
bindweed seeds and roots can hitchhike with contaminated seed and plants,
it is important to buy clean seed and nursery stock.(6) If you think you
have planted something that is contaminated, keep a close watch and remove
bindweed seedlings quickly.(6)
If you
bring soil into your garden, it should be free of bindweed seed and roots.(6)
Borrowed equipment should be cleaned thoroughly before use in your fields
or garden.(2) If you have livestock, be sure their feed doesn't contain
bindweed seeds.(8)
Getting
Rid of Bindweed
“When dealing with field bindweed, the farmer, land manager, or home
owner must recognize that there are no ‘quick-fix’ solutions to eliminate
it.”(3) All techniques require persistence and patience.
Weed
Barriers and Mulches
Black plastic or landscape fabric weed barriers covered with an organic
mulch deprive bindweed of sunlight and have been used successfully to manage
this pest.(6)
When
employing this method, you must be sure to overlap the sheets of plastic
or fabric to prevent the weed from receiving sunlight and be sure that
there are no holes in the material, as the weed is very effective at finding
light.(6) This method can take up to three or four years, so be patient.(8)
An old
(1915) U.S. Department of Agriculture publication suggests using organic
mulches such as straw and paper to smother bindweed, but they need to be
used so thickly(10) that most experts now recommend plastic sheets or landscape
fabric.(5-8)
Hand-pulling,
Hoeing, and Clipping
Seedling bindweed (until it's about a month old) is easy to control by
pulling it up or cultivating with a hoe.
These
techniques are also important for managing older bindweed even though you
won'tkill the plant once it has developed its root system. Eliminating flowers
before they set seed is critical, because one plant may produce 500 seeds
that can remain viable for 50 years if conditions are right.(3) In addition,
removing the above-ground part of the weed repeatedly can deplete the carbohydrate
reserves stored in the roots.
Allow
the plant to grow for about ten days, or until it's about 6 inches long.
Then remove the growing parts to force it to draw on energy stored in the
roots while depriving it of the ability to make more.(5) Eventually, the
plant will die.(2) Be careful when using this method, as bindweed happily
propagates itself from pieces of roots.(7)
Flame
Weeding
Flame weeding serves the same purpose as hand-pulling or clipping. A
flame weeder is a device that uses propane gas and a wand or other structure
to deliver heat (130º F) to a plant's cell walls, causing them to
rupture. If you choose this control method, follow the manufacturer's instructions
and be careful that you do not ignite dry materials and start a fire.(9)
Cultivation
and Competition
Some literature suggests hoeing or cultivating in combination with growing
plants that shade out bindweed.(2,8) The basic idea is to bring in plants
that compete with the weed for food and light. Heavy shading is the key
to this control method.(5)
Farmers
have successfully used sequences of plantings to manage bindweed. One sequence
is rye and vetch, planted in the fall and disked or hoed down in late spring,
followed by buckwheat or oats with peas, disked or hoed down in late summer.
The final step repeats the rye and vetch. The next spring, the land is
ready for growing vegetables.(8) According to the National Sustainable
Agriculture Information Service, farmers have also used pumpkins and sunflowers
to out-compete bindweed.(8) One farmer reported no bindweed problems for
nine years after his bindweed was “shaded and strangled by the pumpkins.”(8)
Alfalfa, legumes, and corn have also reduced bindweed infestations.5 Small-scale
versions of these strategies can be used in a home garden.
Gall
Mites
Bindweed gall mites cause galls to form on the leaves and stems of bindweed;
the result is stunting of the plant, reduced flowering, and some reduction
in the amount of bindweed. During the winter these mites feed on root buds,
stunting root growth. Bindweed gall mites have done well in Texas and New
Mexico.(11,12 )
Conclusion
When the California Department of Food and Agriculture's summarized information
about bindweed, the agency concluded that even when chemicals are used,
control of this tenacious plant is difficult. “Chemical control of field
bindweed generally requires a multiple year approach. There are few herbicides
that provide effective control.”(3)
All sources, regardless of their perspective
about herbicides, stress that in order to control bindweed ongoing vigilance
and effort is required. With persistence, you can achieve a garden that is
free of both pesticides and bindweed problems.
References
1. Austin, D.F. 2000. Bindweed (Convolvulus
arvensis, Convolvulaceae) in North America—From medicine to menace.
J. Torrey Bot. Soc. 127:172-177.
2. Lyons, K.E. 2001. Element stewardship abstract
for Convolvulus arvensis L. field bindweed. The Nature Conservancy.
http://tncweeds.ucdavis.edu/esadocs/documnts/convarv.html.
3. Calif. Dept. of Food and Agriculture. Undated.
Field bindweed (Convolvulus arvensis L.). http://www.cdfa.ca.gov/phpps/ipc/weedinfo/convolvulus.htm.
4. Univ. of Idaho Extension. 1999. Homewise:
No matter what we do, our morning glory weeds come back every year. Any
advice? Aug. 23. http://info.ag.uidaho.edu/homewise/homewise_082399.htm
5. Hodges, L. 2003. Bindweed identification and trol options for organic production. NebFacts. Univ. of Nebraska – Lincoln
Cooperative Extension. http://ianrpubs.unl.edu/horticulture/nf585.htm.
6. Univ. of California Agriculture and Natural
Resources. 2003. Field Bindweed. Pest Notes. Publ. # 7462. http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7462.html.
7. Washington State Univ. Cooperative Extension.
Undated. Hortsense: Weeds: Field bindweed (Wild morningglory): Convolvulus
arvensis. http://pep.wsu.edu/hortsense.
8. Sullivan, P. 2004. Field bindweed control
alternatives. ATTRA. National Sustainable Agriculture Information Service.
http://attra.ncat.org/attra-pub/PDF/bindweed.pdf
9. Lanini, W. T. Undated. Organic weed management
in vineyards. University of California, Davis Cooperative Extension. http://www.nswg.org/tomlanini.htm.
10. Cox, H.R. 1915. The eradication of bindweed or
wild morning-glory. U.S. Dept. of Agriculture Farmers’ Bulletin 368. Washington,
D.C.: Government Printing Office.
11. Littlefield, J.L. 2004. Bindweeds. In Biological
control of invasive plants in the United States, ed. E.M. Coombs et
al. Corvallis OR: Oregon State Universityy Press. Pp. 150-157.
12. New Mexico State Univ. Cooperative Extension Service.
2004. Managing Aceria malherbae gall mites for control of field
bindweed. http://www.cahe.nmsu.edu/pubs/_circulars/CR%20600.pdf.
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This article was originally published as:
Cox, Caroline. 2005. Coping with field bindweed without using
herbicides. Journal of Pesticide Reform 25(1): 6-7
Photo credit: The Nature Conservancy
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