Bindweed - Ask Extension
What is the best way to eradicate bindweed? I have a garden bed that was overcome with it. At this point, all plantings have been removed and as much ...
Knowledgebase
Bindweed #781901
Asked February 15, 2022, 8:23 AM EST
What is the best way to eradicate bindweed? I have a garden bed that was overcome with it. At this point, all plantings have been removed and as much of it as possible has been pulled up (even while knowing that the root system is the focus of removal). I would like to know how to apply herbicide - how much, how often, and whether then covering the area with cardboard/black plastic would be advised. My sense is that this eradication may take more than one season. I look forward to your advise.
Washtenaw County Michigan
Expert Response
Field bindweed (Convolvulus arvensis) is an introduced perennial plant in Michigan. It has a deep central taproot (sometimes 20’ or more) that spreads by rhizomes (underground stems) and seed. Field bindweed has opposite, arrow-head shaped leaves with generally rounded tips. Flowers are funnel-shaped and white or sometimes pink in color.
This is a very tough weed to control, but the following are some options to try, and repeated efforts will likely be needed. Whatever strategy or combination you choose, it is best to act before they flower and produce seed to avoid furthering the infestation.
Persistent physical removal of the aboveground plant material, rhizomes, and roots will eventually deplete the plant of resources, but it could take several years of this to achieve success.
Repeated tillage could be used to deplete the plant of resources, however this will not likely work for your area with the landscape fabric and the other plants. Tillage can also spread the plant around as small rhizome fragments are chopped up and moved.
Planting tall, competitive plants nearby may help shade out the bindweed, as it is not very shade tolerant.
In some cases we recommend the use of landscape fabric on the soil to shade out the bindweed, particularly if the fabric is laid and then covered with mulch. Any holes cut in the fabric for desirable plants may allow bindweed a new avenue to emerge. Complete death via light deprivation is reported to take between 3 to 5 years.
A non-selective herbicide, such as glyphosate (e.g. Roundup Weed and Grass Killer, though there are several other products available) can be effective in controlling field bindweed, but care would be needed to avoid any desirable plants. With many perennials like bindweed you can cut the plant and apply concentrated glyphosate on the cut surface immediately after (<5 min) using a cotton swab or other means. This method helps avoid contacting nearby desirable plants. Late summer to early-fall timing is when glyphosate has the greatest efficacy on perennial weeds because the plants are moving resources to the root system. If you do not have any desirable plants nearby and the bindweed is actively growing you can spray the foliage as directed.
When using products containing glyphosate there are a few important points to consider. First, as with any pesticide, remember to read and follow all labeled instructions. Second, glyphosate is a broad-spectrum herbicide, meaning it will injure or kill other plants contacted during application, so care is needed to avoid green plant material, exposed roots, and injured bark of desired plants. Third, glyphosate is relatively safe in the environment when used as labeled. It adsorbs strongly to soil in most cases (i.e. clay and organic matter), allowing even sensitive crops to be planted shortly after application; meaning no carry over issues are expected. Fourth, glyphosate alone can take up to 14 days to show full activity under ideal growing conditions. Retreatment of the area may be needed depending on the degree of infestation. Glyphosate is most effective for perennial control in the fall, as previously mentioned, but can be applied anytime the plants are actively growing (temperatures consistently above 50F). Finally, be sure that the product you choose has only the active ingredient glyphosate or glyphosate + pelargonic acid. Products with additional active ingredients may have other unwanted effects and may delay the planting of other plants in the coming season(s).
Please let me know if you have any questions.
This is a very tough weed to control, but the following are some options to try, and repeated efforts will likely be needed. Whatever strategy or combination you choose, it is best to act before they flower and produce seed to avoid furthering the infestation.
Persistent physical removal of the aboveground plant material, rhizomes, and roots will eventually deplete the plant of resources, but it could take several years of this to achieve success.
Repeated tillage could be used to deplete the plant of resources, however this will not likely work for your area with the landscape fabric and the other plants. Tillage can also spread the plant around as small rhizome fragments are chopped up and moved.
Planting tall, competitive plants nearby may help shade out the bindweed, as it is not very shade tolerant.
In some cases we recommend the use of landscape fabric on the soil to shade out the bindweed, particularly if the fabric is laid and then covered with mulch. Any holes cut in the fabric for desirable plants may allow bindweed a new avenue to emerge. Complete death via light deprivation is reported to take between 3 to 5 years.
A non-selective herbicide, such as glyphosate (e.g. Roundup Weed and Grass Killer, though there are several other products available) can be effective in controlling field bindweed, but care would be needed to avoid any desirable plants. With many perennials like bindweed you can cut the plant and apply concentrated glyphosate on the cut surface immediately after (<5 min) using a cotton swab or other means. This method helps avoid contacting nearby desirable plants. Late summer to early-fall timing is when glyphosate has the greatest efficacy on perennial weeds because the plants are moving resources to the root system. If you do not have any desirable plants nearby and the bindweed is actively growing you can spray the foliage as directed.
When using products containing glyphosate there are a few important points to consider. First, as with any pesticide, remember to read and follow all labeled instructions. Second, glyphosate is a broad-spectrum herbicide, meaning it will injure or kill other plants contacted during application, so care is needed to avoid green plant material, exposed roots, and injured bark of desired plants. Third, glyphosate is relatively safe in the environment when used as labeled. It adsorbs strongly to soil in most cases (i.e. clay and organic matter), allowing even sensitive crops to be planted shortly after application; meaning no carry over issues are expected. Fourth, glyphosate alone can take up to 14 days to show full activity under ideal growing conditions. Retreatment of the area may be needed depending on the degree of infestation. Glyphosate is most effective for perennial control in the fall, as previously mentioned, but can be applied anytime the plants are actively growing (temperatures consistently above 50F). Finally, be sure that the product you choose has only the active ingredient glyphosate or glyphosate + pelargonic acid. Products with additional active ingredients may have other unwanted effects and may delay the planting of other plants in the coming season(s).
Please let me know if you have any questions.
