A basic steam cleaner may also do the job if you can’t find a weed steamer. Look for a device that can heat the steam up to at least 250 °F (121 °C). [3] X Research source While agricultural weed steamers cost thousands of dollars, you can get a small garden steamer for $100 USD or less. Hot steam kills weeds by exploding the cells within the leaves, preventing the plant from absorbing any more nutrients. You may need to repeat the process later in the growing system if the morning glories return. [4] X Research source
As an alternative to plastic or fabric, you can also lay down overlapping sheets of cardboard over the morning glories, then cover them with mulch. However, since cardboard will eventually degrade, you’ll have to replace it at least once a year. Check frequently for areas where the bindweed or morning glory vine has started to push up through the mulch cover. Pull up any stray tendrils or blast them with steam or a herbicide. [6] X Research source
Systemic herbicides attack the entire plant, including the roots. You may need to apply the herbicide several times for it to work. You can also apply pre-emergent herbicides, such as 2,4-D or dicamba, on the ground in early spring to kill seedlings before they emerge. However, you’ll probably need to combine this method with using systemic herbicides on the mature plants. [9] X Research source Follow the directions on the package carefully. Cover any other plants nearby that you want to protect from the herbicide. Wear any protective gear recommended on the packaging, such as nitrile gloves and safety goggles. [10] X Trustworthy Source University of California Division of Agriculture and Natural Resources Extension program of the University of California system devoted to educating and improving local communities Go to source
Other alternative herbicides that unfortunately will not work on morning glories include citric or acetic acid, plant oils (such as clove or lemongrass oil), and household cleansers (such as Borax).
You may also be able to kill them by unwinding them from around their host plant or structure, and then rewinding them again in the opposite direction.
The best combination of methods may depend on factors like how large the infestation is and what kinds of desirable plants you’re trying to grow in the area. For instance, in a garden, you might find it most effective to smother the vines with fabric and mulch for a few years, then replant the area with a decorative groundcover. In a larger area, like a yard or field, a combination of tilling and herbicide applications might work best.
It may take a few years of hard work to completely beat back a morning glory infestation. Baby plants can regenerate from root fragments in just a few weeks, so check frequently for new growth after treating an area.
Burning the pulled-up morning glory plants. Composting any vines that haven’t been treated with pesticides. However, you’ll need to check your compost pile or bin regularly and get rid of any growing seedlings. Allowing the weeds to rot thoroughly in a bucket of water before adding them to your compost pile or bin. [17] X Research source
Once a morning glory vine is established, it will begin to spread and grow an extensive, complicated root system. While you can hand-pull more mature morning glories, you’ll need to keep doing it repeatedly every 2-3 weeks over a period of at least 3 years. [20] X Research source While mature bindweed roots can grow as deep as 20 feet (6. 1 m) under the soil, most of them won’t grow deeper than about 2 feet (0. 61 m). However, new plants can easily grow from small root fragments that are left behind. [21] X Research source If you choose to pull up mature vines, dig deep with a hoe or garden fork and pull out as many of the roots as possible so that they don’t sprout new plants.
After you plant your new ground cover, be vigilant! If you notice new morning glory vines starting to grow among the desirable plants, pull them out as soon as you see them.
This can also be a problem when you try to hand-pull morning glory vines. To minimize the risk of spreading live root fragments around, stick to pulling up seedlings instead of mature plants as much as possible. While repeatedly hand-pulling mature plants can eventually weaken and kill them, it’s important to dig deep and remove as many of the roots from the ground as possible to keep them from growing back. Use a garden fork or hoe to dig out deep roots. [24] X Trustworthy Source Royal Horticultural Society Leading gardening charity in the U. K. providing resources for identifying, growing and caring for flowers and other plants Go to source
For the best results, install the barriers in late winter or early spring, before new morning glories have a chance to get established. [26] X Trustworthy Source Royal Horticultural Society Leading gardening charity in the U. K. providing resources for identifying, growing and caring for flowers and other plants Go to source You can buy prefabricated weed barriers or make your own from materials like fabric, paving slabs, or edging board. These are better options than plastic sheeting, which tends to degrade quickly.