Field bindweed, the morning glory-type weed is a perennial that can be a very persistent problem in gardens, flower beds, and other parts of the yard. The plant can grow prostrate, with stems up to ten feet long, or it can climb like a vine. Blossoms are white or pink and shaped like a funnel. This weed reproduces both by seed and by creeping roots. The root system is deep, growing as deep as 27 feet, so pulling or hoeing the weed is ineffective. According to one study, it required 13 years to eliminate bindweed using this method; any shoots that are missed will continue to nourish the vast root system.
To control field bindweed in areas where it is well-established, the use of an herbicide can be more practical and usually much more effective. Herbicides that will move downward into the root system are required to kill the vegetative growth nodes on the roots of field bindweed. Fall herbicide applications for field bindweed are most effective, applied shortly before frost. Avoid using herbicides when the field bindweed needs water because when plants are drought-stressed they slow down all internal activity, thus slowing transport of the systemic herbicides to the roots. Contact your County Extension agent for assistance in selection and application of herbicides.
Mulching can sometimes be effective, but must be done with materials which bindweed can not penetrate, such as fabric weed barriers. The entire area infested must be covered for a minimum of one entire growing season or longer. When fabric weed mats are used, the entire area should be mulched to eliminate shoots that emerge around the edges of between strips of mat, allowing the plants to survive. Horizontal roots can extend for many feet. Plastic mulches do not work because the weed can penetrate them.
Relatively new herbicides that are almost non-toxic are the soap -based herbicides. However, they will kill only the portion of the plant with which they come in contact, so in the case of deep-rooted perennials such as field bindweed, which reproduce from rootstalk as well as seed, the herbicidal soaps are ineffective as they will not move down into the root system.