Thank you for your question about bindweed. There are a variety of online resources that are free and available to the public that answer gardening questions and are based upon research out of University Horticulture Schools. Plant Talk is one such resource that is sponsored, in part by Colorado State University. The one that tackles the problem of bindweed is #2104 https://planttalk.colostate.edu/topics/weeds-cultural-problems/2104-controlling-bindweed/

In the article, the author suggests “No one treatment will eliminate established bindweed in one season. A multi-step approach is best: prevent the vine from producing seeds as they can survive for 20 years, overplant the area to outcompete and remove top growth when visible. Hand-pulling well-established bindweed generally does not kill it because of its root system but persistence can reduce energy in the roots. Bindweed is a sun-loving plant, so shading it out with cloth or other plants can be an effective control….Herbicides such as Round-up, 2,4-D, dicamba or related chemicals can be effective in managing bindweed, but killing it with herbicides takes several applications over a period of years. Late summer and early fall applications are most effective. In a lawn environment, 2,4-D and related herbicides are preferred. Round-up or 2,4-D can also be used in flower beds and vegetable gardens. Be sure to apply 2,4-D when temperatures are between 65 degrees and 85 degrees Fahrenheit and winds are less than five mph.” The article warns: “It is important not to spray desirable plants with herbicides because it may kill those plants. Sponging or painting the bindweed with an herbicide is best when bindweed and desirable plants are in close proximity.”