By Megan Wannarka
About the Plant
Common Buckthorn (Latin name Rhamnus cathartica) is a well-known naturalized invasive bush in North America. Native to Europe, northwest Africa, and western Asia. It was brought to the US as a popular hedging material. The greenish-yellow flowers have 4 petals and typically are in bloom from April until July turning into small black fruit. The fruit is mildly poisonous for humans and most other animals, but birds eat them and disperse seeds. Common Buckthorn differs from similar-looking chokecherry (Prunus virginiana) as each fruit contains three to four seeds. Both grow in the same form and bark are nearly identical, but buckthorn leaves have smooth margins, and the fruit clusters at the leave axils contain 2-3 seeds. (Thayer, 2006)
Buckthorn is also known as سدر مسهل in Arabic; Դժնիկ լուծողական in Armenian; Hesilahar in Basque; Жасцёр слабіцельны in Belarusian; pasjakovina in Croatian; řešetlák počistivý in Czech; vrietorn in Danish; wegedoorn in Dutch; harilik türnpuu in Estonian; orapaatsama in Finnish; nerprun purgatif in French; ბაკთორნი in Georgian; purgier-kreuzdorn or kreuzdorn in German; varjútövis in Hungarian; hajdina or pohànka in Hungarian; Spino cervino in Italian; geitved in Norwegian; اشنگور in Persian; szakłak pospolity in Polish; Крушина слабительная in Russian; Паздрен in Serbian; pohánka jedlá in Slovak; rešetliak prečisťujúci in Slovenian; Espino cerval in Spanish; getapel in Swedish; adi cehri in Turkish; Жостір проносний in Ukrainian; rhafnwydden rhafnwydd in Welsh; respectively. (“common buckthorn names – Encyclopedia of Life,”)
Image 1 Common Buckthorn (Rhamnus cathartica) berries are clustered with each set of leaves at the nodes.
Seeding and yields
As invasive species in most North America, the ideal would be for this plant not to propagate. Sadly buckthorn is challenging to control as it sprouts vigorously, and seeds can germinate for many years. (Wikipedia Contributors, 2020) Multi-year management and removal are recommended in many US states that have deemed it an invasive weed. (MN Department of Natural Resources)
Buckthorn honey is caramel colored and liquid honey. The flavor is fruity and full-bodied, reminds me of Juicy Fruit gum. Buckthorn, while it might be seemingly everywhere as an invasive species, the bloom of this plant occurs at the same time as other major honey producing plants. Black locust (Robinia pseudoacacia) and American Basswood (Tilia americana) bloom roughly April until June making Buckthorn honey harder single-source honey to obtain.
Image 2 Picture of Buckthorn flowers image by Dr. Oliver Schneider (Oliver s. at de.wikipedia) / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0)
Beekeeping notes (growing season, soil preference, nectar, and honey yields)
“Height 6-8ft Spread 6-8ft Flowers May” (Mountain & Bee Research Association, 1975)
“Large nectaries yield nectar freely. The European Buckthorn (R. cathartica) has become established in many eastern states, and the Carolina buckthorn (R. Carolinana) is a native species.” (Lovell, 1966)
“…grows in the upper Midwest as either small trees or tall shrubs. Originally from Eurasia, they were introduced to the Midwest as ornamentals as early as 1849. They are now well established and spreading rapidly. Although common buckthorn is more widespread, glossy buckthorn is particularly aggressive in wet areas. Both species produce a dense shade that eliminates native tree seedlings, saplings, and ground layer species. Long growing seasons, prolific production of berries that are attractive to birds, rapid growth rate…Prefers woods or woodland edges; is particularly aggressive on well-drained soils; also found in prairies, thickets, old fields, yards, and along roadsides. 10-25 feet high. Bloom May through June, fragrant. Control: The most effective control for buckthorns is to recognize their presence early and remove plants before they begin to produce fruit. Small plants can be pulled with soil that is damp. Larger plants…can be dug or pulled. When a large number of buckthorns seedlings are present, controlled burns in fall or early spring in fire-adapted plant communities may kill seedlings, especially those in the first year of growth. Burning may need to be repeated annually or biannually for two or three years to deplete the seed bank. Girling has produced mixed results for controlling buckthorn. In wetlands with artificially lowered water tables, restoring water to its previous levels will often kill glossy buckthorn.” (Czarapata, 2005)
References and Additional Resources
common buckthorn names – Encyclopedia of Life. Retrieved August 19, 2020, from https://eol.org/pages/582356/names
Czarapata, E. J. (2005). Invasive Plants of the Upper Midwest: An Illustrated Guide to Their Identification and Control. Madison, Wisconsin: University of Wisconsin Press.
Lovell, H. B. (1966). Honey Plants Manual: A Practical Field Handbook for Identifying Honey Flora (2nd ed.). Louisville: A. I. Root Company.
Mountain, M. F., & Bee Research Association. (1975). Trees and shrubs valuable to bees. Chalfont St Peter (Hill House, Chalfont St Peter, Gerrards Cross, Bucks. SL9 0NR): Bee Research Association.
MN Department of Natural Resources. Buckthorn management | Minnesota DNR. Retrieved August 19, 2020, from MN DNR website: https://www.dnr.state.mn.us/invasives/terrestrialplants/woody/buckthorn/control.html
Pavek, P. L. (2016). Buckwheat Plant Guide (Fagopyrum esculentum). Retrieved from USDA-Natural Resources Conservation Service website: https://plants.usda.gov/plantguide/pdf/pg_faes2.pdf
Thayer, S. (2006). The Forager’s Harvest: A Guide to Identifying, Harvesting, and Preparing Edible Wild Plants. United States: Forager’s Harvest.
Wikipedia Contributors. (2020). Rhamnus cathartica. Retrieved August 19, 2020, from Wikipedia website: https://en.wikipedia.org/wiki/Rhamnus_cathartica