Ipomoea spp.
Also known as: morning glory, tievine
Morningglories are one of the most common weeds in North American agriculture. These warm-season, annual, vining plants can be found in cultivated fields, perennial crops, roadsides, pastures, fences, hedges, and natural areas across the United States. The Ipomoea genus contains more than 600 species, many of which are considered weedy in some way. The most common weedy species in the United States are all native.
Morningglories infest most major crops such as corn, soybean, sorghum, and cotton. They compete with crops for water, nutrients, and especially light, if they grow enough to cover the crop’s canopy. They are also known for severely interfering with crop harvest. Their vining stems can wrap around the moving parts of harvesting equipment, slow down harvest operations, and increase grain losses during harvest, while seed contamination can reduce the value of the crop. Additionally, morningglory seeds germinate throughout the summer, even in shaded conditions, so season-long management is required to avoid issues at harvest.
Identifying Features
Although the appearance and growth characteristics of morningglory species vary considerably, some characteristics are common among species. They are warm season, annual plants, with optimum germination rates at around 77 °F (25 °C), which occur throughout the growing season as long as moisture is available.
They exhibit vining or spreading growth habits, preferring to climb on other plants or structures. The seeds are wedge-shaped, ranging from black to brown in color, and smooth to hairy in texture. The seeds are larger (>5 mm) than other weed species.
Morningglory cotyledons are one of their most easily identifiable characteristics. The cotyledons are “butterfly shaped,” with deep indentations. The leaves are arranged alternately and generally have a heart shape with lobes, but the specific shape and number of lobes vary by species. The flowers are cone-shaped, with a characteristic 5-pointed star-shaped pattern in the petals. The fruits are dry, round capsules, which usually contain three to six seeds. The specific identifying features and photos of five most common weedy species in the U.S. are outlined in the table below:
Other weedy annual morningglory species in the United States include red morningglory (Ipomoea coccinea), entireleaf morningglory (Ipomoea hederacea var. integriuscula), and cypressvine morningglory (Ipomoea quamoclit). Some perennial species like swamp morningglory (Ipomoea aquatica) and bigroot morningglory (Ipomoea pandurata) can also be problematic.
Seed Production
Morningglories are prolific seed producers. Each flower produces a seed pod, which can contain three to six seeds each. The seeds are large and have been reported to persist in the soil for about six years, but some sources report that buried seeds can survive for up to 39 years. Their long dormancy period makes it hard to deplete the seedbank. Morningglories can produce seeds as soon as nine weeks after emergence, but most seeds are produced in the mid to late summer. Depending on species and how large the plants grow, morningglories can produce from 5,000 to 15,000 seeds per plant.
The seeds can germinate even at depths of more than 4 inches, and they show high rates of viability, reaching >90% under the optimal conditions. Since seeds are large, they are commonly harvested with grain, increasing the contamination potential and reducing the value of the grain. Some morningglory species like wild sweet potato (I. pandurata), tievine (I. cordatotriloba), and water spinach (I. aquatica) can also be perennials and come back from the taproot if not controlled.
Herbicide Resistance
Although most morningglory species are naturally tolerant to glyphosate, glyphosate-resistant tall morningglory populations have been confirmed in Tennessee, North Carolina, and Virginia.
Integrated Weed Management Options
Mechanical Weed Control
Shallow, inter-row cultivation can be effective to control emerged seedlings, especially late-emerged seedlings. However, inversion tillage to bury the seeds are not effective tactics, because morningglories can germinate even when buried more than 4 inches deep. In peanuts, pre-harvest top-mowing (only the top few inches) can help to remove morningglory escapes and improve harvest efficiency.
Crop Rotation
Crop rotation can be one of the most effective cultural strategies to manage morningglories, especially when perennial forages or small grains are added into the rotation. Fall sown small grains and perennial crops can be highly competitive and disrupt the life cycle and germination patterns of morningglories. However, rotating warm-season row crops is not as effective, because morningglories are adapted to all common row crops in the U.S. Even so, row crop rotation allows for alternating herbicides and modes of action, which can prevent herbicide resistance in the long term.
Planting Arrangement
Higher planting populations and narrow row spacing can help to slow down morningglory germination rates and suppress growth. However, morningglories can emerge even in shaded conditions and climb on established crops.
Mulches and Cover Crops
Plastic mulches are effective to prevent emergence of morningglories. Cover crops alone are not as effective for morningglory control as they are for small-seeded weeds. Although high biomass levels and allelopathy from small grain cover crops may provide some degree of suppression, additional management is usually necessary for complete control of morningglories.
Herbicide Control Options
Resources
https://ipm.ucanr.edu/weeds-identification-gallery/morningglories/#gsc.tab=0
https://cals.cornell.edu/weed-science/weed-profiles/morningglories
https://weedid.missouri.edu/weedinfo.cfm?weed_id=138
https://weedid.cals.vt.edu/profile/310
https://weedid.missouri.edu/weedinfo.cfm?weed_id=142
https://www.wildflower.org/plants/result.php?id_plant=ipcoc2
https://extension.missouri.edu/media/wysiwyg/Extensiondata/Pub/pdf/miscpubs/mx1131.pdf
https://site.extension.uga.edu/colquittag/2020/03/morningglory-control-in-field-corn/
Citations
Asami, H., Ishioka, G., & Homma, K. (2021). Relationship between storage period and germination of Ipomoea hederacea var. integriuscula seeds under natural condition. Weed biology and management, 21(4), 183-191.
Barroso, A. A. M., Ferreira, P. S. H., & Martins, D. (2019). Growth and development of Ipomoea weeds. Planta Daninha, 37, e019186421.
Bryson, C. T., & DeFelice, M. S. (Eds.). (2009). Weeds of the South. University of Georgia Press. Pages 165-174.
Haddock, H., & Oreja, F. H. (2026). Seed dormancy and germination ecology of three morningglory species: Ipomoea lacunosa, I. hederacea, and I. purpurea. Seeds, 5(1), 3.
Egley, G. H., & Chandler, J. M. (1983). Longevity of weed seeds after 5.5 years in the Stoneville 50-year buried-seed study. Weed Science, 31(2), 264-270.
Gomes, L. F., Chandler, J. M., & Vaughan, C. E. (1978). Aspects of germination, emergence, and seed production of three Ipomoea taxa. Weed Science, 26(3), 245-248.
Heap, I. The International Herbicide-Resistant Weed Database. Online. Thursday, April 2, 2026. Available at www.weedscience.org
Horak, M. J., & Wax, L. M. (1991). Germination and seedling development of bigroot morningglory (Ipomoea pandurata). Weed Science, 39(3), 390-396.
Kuester, A., Chang, S. M., & Baucom, R. S. (2015). The geographic mosaic of herbicide resistance evolution in the common morning glory, Ipomoea purpurea: Evidence for resistance hotspots and low genetic differentiation across the landscape. Evolutionary applications, 8(8), 821-833.
Oliveira, M. J., & Norsworthy, J. K. (2006). Pitted morningglory (Ipomoea lacunosa) germination and emergence as affected by environmental factors and seeding depth. Weed Science, 54(5), 910-916.
Pittman, K. B., Barney, J. N., & Flessner, M. L. (2020). Cover crop residue components and their effect on summer annual weed suppression in corn and soybean. Weed Science, 68(3), 301-310.
Price, A. J., Williams, J. P., Duzy, L. A., McElroy, J. S., Guertal, E. A., & Li, S. (2018). Effects of integrated polyethylene and cover crop mulch, conservation tillage, and herbicide application on weed control, yield, and economic returns in watermelon. Weed Technology, 32(5), 623-632.
Singh, M., Ramirez, A. H., Sharma, S. D., & Jhala, A. J. (2012). Factors affecting the germination of tall morningglory (Ipomoea purpurea). Weed Science, 60(1), 64-68.
Toole, E. H., & Brown, E. (1946). Final results of the Duvel buried seed experiment. Journal of Agricultural Research. 72, 201-210.
Van Etten, M., Lee, K. M., Chang, S. M., & Baucom, R. S. (2020). Parallel and nonparallel genomic responses contribute to herbicide resistance in Ipomoea purpurea, a common agricultural weed. PLoS genetics, 16(2), e1008593.
Author
Gustavo Camargo Silva, Texas A&M University
Editors
Emily Unglesbee, Virginia Tech
John Wallace, Penn State University
Muthukumar Bagavathiannan, Texas A&M University
Mark VanGessel, University of Delaware
Michael Flessner, Virginia Tech
