More on ID'ing the Winding Weed - Ask Extension
Here with more photos to add to the evidence I sent a couple weeks ago. This weed is taking over my wild flower garden. It twists around anything ver...
Knowledgebase
More on ID'ing the Winding Weed #848665
Asked September 05, 2023, 12:17 PM EDT
Here with more photos to add to the evidence I sent a couple weeks ago. This weed is taking over my wild flower garden. It twists around anything vertical - including the corn in the field across the street, as you can see from one of the photos.
I would appreciate your recommendation on how to get rid of it - IT CANNOT BE PULLED UP because the stem immediately breaks. Coating leaves with Round-up has not helped. The wild flowers grow quite thickly. Would it work to wait till cold weather, dig up the whole bed and spray Round-Up on it, then replant in the spring? Or doesn't Round-Up work that way?
Talbot County Maryland
Expert Response
This is a member of the morning glory family; in particular we suspect Small White Morning-Glory (Ipomoea lacunosa) based on the leaf shape, which looks too rounded to be either of the common invasive vines Bindweed (there are at least two similar-looking species whose leaf edges are more angular). While Bindweeds are perennial, the Small White Morning-Glory is annual and will die this coming winter. It is tap-rooted, though, which makes hand removal very difficult, as you noted.
The simplest approach is to let it die out this winter and prevent next year's seedlings from germinating in spring, either with mulching exposed soil, pulling-up very young plants as they appear, or if necessary, with careful use of a pre-emergent herbicide.
If this is perennial Bindweed instead, or if some is mixed-in with this other annual, then you'd need to treat as much foliage as possible with a systemic herbicide that will be absorbed to kill roots; late summer and early autumn is a good time to try this for perennial plants since above-ground food reserves are starting to be moved into roots for winter storage. Follow all label directions for use of whichever product you choose, and plan on cutting-back as much of the top growth as possible first (all you have to do is disconnect it from the roots in the ground and let it die on its own...it doesn't have to be unwound first) in order to force regrowth from the roots. This will greatly reduce how much herbicide would be needed because you'll only need to treat that limited amount of regrowth, plus it will be easier to treat with less risk of contaminating the foliage of desirable plants, as these types of herbicides can damage them too if their foliage is sprayed.
The active ingredient in Roundup is glyphosate, a systemic herbicide which needs to be absorbed by foliage (and maybe in rare cases, fresh-cut stumps of shrubs or small trees); it will not work by being applied to bare soil, nor is it a pre-emergent that will affect germinating seeds. In fact, with soil contact, it degrades fairly quickly. Pre-emergent herbicide should be the last resort when trying to prevent weed growth, especially for exposed bare soil; instead, using a two- to three-inch mulch layer is usually sufficient for all but the toughest weeds. Roundup sprayed on Morning-glory foliage should be effective, though results might not be visible for a week or more after treatment depending on how vigorous the plant is and how well a treatment was applied, since it needs to be thorough and coat all weed foliage. Re-application may also be needed for plants that are well-established and aggressive growers. The label should provide guidance in that case as to how long to wait before a reapplication is made.
If you allow your wildflowers to self-sow (produce their own seed and germinate as they will in spring), then you won't be able to use a pre-emergent for this weed without also preventing germination of the desirable plants. (Granted, mulch as a germination preventative for weeds will do the same, keeping desirable seeds from germinating well also.) In that case, the best approach will just be the most tedious one, which is to monitor for new seedlings of this weed and rogue them out as soon as they're found before their roots can get too extensive.
Miri
The simplest approach is to let it die out this winter and prevent next year's seedlings from germinating in spring, either with mulching exposed soil, pulling-up very young plants as they appear, or if necessary, with careful use of a pre-emergent herbicide.
If this is perennial Bindweed instead, or if some is mixed-in with this other annual, then you'd need to treat as much foliage as possible with a systemic herbicide that will be absorbed to kill roots; late summer and early autumn is a good time to try this for perennial plants since above-ground food reserves are starting to be moved into roots for winter storage. Follow all label directions for use of whichever product you choose, and plan on cutting-back as much of the top growth as possible first (all you have to do is disconnect it from the roots in the ground and let it die on its own...it doesn't have to be unwound first) in order to force regrowth from the roots. This will greatly reduce how much herbicide would be needed because you'll only need to treat that limited amount of regrowth, plus it will be easier to treat with less risk of contaminating the foliage of desirable plants, as these types of herbicides can damage them too if their foliage is sprayed.
The active ingredient in Roundup is glyphosate, a systemic herbicide which needs to be absorbed by foliage (and maybe in rare cases, fresh-cut stumps of shrubs or small trees); it will not work by being applied to bare soil, nor is it a pre-emergent that will affect germinating seeds. In fact, with soil contact, it degrades fairly quickly. Pre-emergent herbicide should be the last resort when trying to prevent weed growth, especially for exposed bare soil; instead, using a two- to three-inch mulch layer is usually sufficient for all but the toughest weeds. Roundup sprayed on Morning-glory foliage should be effective, though results might not be visible for a week or more after treatment depending on how vigorous the plant is and how well a treatment was applied, since it needs to be thorough and coat all weed foliage. Re-application may also be needed for plants that are well-established and aggressive growers. The label should provide guidance in that case as to how long to wait before a reapplication is made.
If you allow your wildflowers to self-sow (produce their own seed and germinate as they will in spring), then you won't be able to use a pre-emergent for this weed without also preventing germination of the desirable plants. (Granted, mulch as a germination preventative for weeds will do the same, keeping desirable seeds from germinating well also.) In that case, the best approach will just be the most tedious one, which is to monitor for new seedlings of this weed and rogue them out as soon as they're found before their roots can get too extensive.
Miri
