Jessica Green, Oregon State University
A Many Little Hammers Approach
Ecological Management has been described as a many little hammers approach to weed management. No single strategy can be effective in reducing field bindweed populations, but the ecological management plan described below, if applied with persistence, can improve your situation.
Step 1: Assess and monitor. Field bindweed is often confused with other species, including ornamental morning glories, hedge bindweed, black bindweed, and other weeds. See a comparative ID guide HERE. Hedge bindweed can be considered a weed, because it does have a twining growth habit and can overtake existing vegetation. It is more common in hedgerows and riparian areas, rather than production fields. Field bindweed, on the other hand, is drought tolerant and considered an invasive weed in agroecosystems as well as in rangelands and natural areas.
Before implementing a management strategy for field bindweed, take the time to make some initial assessments. Document and record:
- Leaf morphology and floral characteristics. Back up this information with close-up photographs.
- Monitor changes in plant density by defining a few areas and noting the number of stems and percent open ground that is visible. Mark the locations and return periodically to re-assess.
- Monitoring provides a good baseline and will provide some indication of the success of management tactics. The standardized impact monitoring protocol (SIMP) is easy to use for this purpose (see the Additional Reading section below).
Consider site characteristics and how they might influence management. Soil moisture at 1, 6, and 12-inch depths, soil texture (percentage sand, silt, and clay), soil organic matter and soil pH all could be important factors in the persistence of field bindweed. Is the area suitable for repeated tillage? Is it located next to a waterway or sensitive habitat that could reduce options for herbicide use?
Step 2: Prevent. Do everything you can to provide a competitive edge to desired vegetation. Shade is a particularly effective strategy against field bindweed; cover crops and intercropping can provide shade if they are suited to the overall production system.
- Field bindweed can thrive in low nutrient or drought-stricken areas, so pay careful attention to undisturbed land that may be a source of field bindweed.
- Seed production is reduced under drought conditions; vegetative growth is less affected. Bindweed can be successful even under drought conditions in the absence of competition from other plants and where soils are deep. Field bindweed sometimes establishes from seed, but the more common route by far is from pieces of root and shoot that are moved around a field.
- If nothing else can be done to control field bindweed, at least mow regularly to prevent seed production
- Avoid introducing field bindweed-contaminated compost, topsoil, or plant stock onto your property. Field bindweed was introduced to North America as a cover crop seed and in potted materials. Bindweed is routinely spread through compost, potting media, and even potted plants.
Step 3: Integrate Strategies. Use all available tools to interfere with field bindweed’s life cycle.
- Initially, applying mulch or groundcover to reduce access to light can be helpful. Be vigilant and manage the shoots that escape the edges of the cover.
- If available, thermal weed control tactics like steam weeding and propane flaming may reduce shoot biomass. Apply these tactics carefully to avoid damage to the crop.
- Avoid light, infrequent cultivation - this can redistribute root fragments that have full capacity to regrow. Tillage can decrease the carbohydrate reserves stored in roots, but it must be deep (more than 6-inches), frequent (every 2-3 weeks), and consistent (for 3-5 years). Tillage alone is an impractical solution for most crops.
- Field bindweed is most sensitive to environmental stress within the first 2 weeks after emergence. This is the time when deep tillage or pulling exert the greatest control over field bindweed. Biological control agents work best in natural landscapes or rangeland because there is less disturbance, and the insects have a better chance of becoming established. Work with your local Department of Agriculture to determine whether a biological weed control program is available. Remember that biological control is meant to reduce a weed population over time, not eliminate it completely. Grazing can be beneficial in certain settings. Sheep are notably good at reducing bindweed, and pigs are even better because they enjoy digging for the roots. Mild toxicity has been reported in horses, but only when no other food source was available.
If bindweed persists after integrating these strategies, and if it causes economic or ecological impacts, treatment with NOP listed herbicides may be warranted. Herbicides that are applied to foliage work best when the weed is flowering (May to August) or in fall before the first frost.
IMPORTANT: Before using any pest control product in your organic farming system:
- read the label to be sure that the product is labeled for the crop and pest you intend to control, and make sure it is legal to use in the state, county, or other location where it will be applied,
- read and understand the safety precautions and application restrictions, and
- make sure that the brand name product is listed in your Organic System Plan and approved by your USDA-approved certifier. If you are trying to deal with an unanticipated pest problem, get approval from your certifier before using a product that is not listed in your plan—doing otherwise may put your certification at risk.
Note that, although OMRI and WSDA lists are good places to identify potentially useful products, all products that you use must be approved by your certifier. For more information on how to determine whether a pest control product can be used on your farm, see the related article, Can I Use This Input On My Organic Farm?
Step 4: Reassess and Adjust.
- Perennial weeds such as field bindweed can persist for many years. Do not become complacent if an early management success reduces field bindweed impact in one year or one cropping cycle.
- Monitor at different times of year and in different areas of the field or landscape.
- Regrowth and small infestations are always easier to manage when they are first noticed.
- Know what young field bindweed looks like; seedlings arising from seed have cotyledons (seed leaves), but new emerging shoots do not.
This article is part of a series on Integrated Management of Field Bindweed. See also:
- Field Bindweed: Why it's so Hard to Manage
- Organic Management of Field Bindweed: Case Studies and Research Findings
- Liebman, M. and E. Gallandt, Many Little Hammers: Ecological Management of Crop-Weed Interactions, In Ecology in Agriculture, Ed: L.E. Jackson, 1997, Academic Press.
- Milan, J. et al. Standardized Impact Monitoring Protocol (SIMP) Biological Control Monitoring Form. https://www.ibiocontrol.org/simp.cfm
- Morishita, D., R. Callihan, C. Eberlein, J. McCaffery, E. Thill. 2005. Field Bindweed (PNW 580), Univ of Idaho. https://smallgrains.wsu.edu/wp-content/uploads/2013/11/Field-Bindweed.pdf
- Mostafavi, K. and F. Golzardi. 2012. Effects of Salt and Drought Stresses on Germination and Seedling Growth of Bindweed (Convolvulus arvensis L.). J. of Applied Sciences, Engineering, and Technology 4: 4305-4313,
- Orloff, N., Mangold, J., Miller, Z., and F. Menalled (2018). A meta-analysis of field bindweed (Convolvulus arvensis L.) and Canada thistle (Cirsium arvense L.) management in organic agricultural systems. Agriculture, Ecosystems & Environment 254: 264-272.
- Shaw, D.R., H.R. Smith, A.W. Cole and C.E. Snipes. (1987). Influence of environmental factors on small flower morningglory (Jacquemontia) germination and growth. Weed Science 35: 519-523.