Buckthorn: What It Is, Benefits, Dosage, and Sources

Buckthorn refers to a group of woody plants, primarily shrubs or small trees, found in various parts of the world. The term "buckthorn" can be confusing because it encompasses several distinct species, some of which are considered beneficial, while others are aggressive invasive species. Understanding the specific type of buckthorn is crucial, as their characteristics, ecological impacts, and potential uses vary significantly. This article explains what buckthorn is, distinguishing between common types, and discuss their associated benefits, potential side effects, and natural sources.

Identifying Common Buckthorn and Understanding Its Impact

When people refer to "buckthorn" in North America, they often mean Rhamnus cathartica, also known as Common Buckthorn, or Frangula alnus (formerly Rhamnus frangula), known as Glossy Buckthorn or Alder Buckthorn. Both are non-native, invasive species that have significantly altered ecosystems across the continent. They were originally introduced from Eurasia as ornamental plants or for hedges due to their hardiness and ability to grow in various conditions.

Common Buckthorn is typically a tall shrub or small tree, reaching heights of 10-25 feet. Its leaves are oval, finely toothed, and often remain green late into the fall after most native deciduous plants have lost their foliage. A key identifying feature is the small, sharp thorn found at the tip of many branches – hence the name "buckthorn." The bark is dark, often with orange lenticels (pores) visible on younger stems. Its berries, which ripen to black in late summer and fall, are a significant food source for birds, but they act as a laxative, causing birds to quickly disperse the seeds, further aiding its spread.

Glossy Buckthorn has similar characteristics but often lacks the thorn at the branch tip. Its leaves are usually untoothed and have a glossy appearance. Both species thrive in a wide range of habitats, from open fields and forest edges to dense woodlands, outcompeting native vegetation for light, water, and nutrients. This aggressive growth habit reduces biodiversity, alters soil chemistry, and negatively impacts wildlife habitat. For example, some native insect larvae that feed on specific host plants cannot utilize buckthorn, disrupting local food webs.

The practical implications of common buckthorn's presence are substantial for landowners and land managers. Its dense thickets can make areas impassable, reduce timber value, and degrade recreational spaces. Controlling its spread often requires persistent effort, including manual removal, cutting, and herbicide application, particularly when plants are mature. Early identification and removal are key to preventing widespread infestation.

Common Buckthorn – Profile and Resources

To further clarify the distinction and impact, let's detail the profile of Rhamnus cathartica, or Common Buckthorn. This species is listed as invasive in many regions, particularly across the northern United States and parts of Canada. Its rapid proliferation is a major ecological concern.

Ecological Impact:

• Shading: Common Buckthorn leafs out early in spring and retains its leaves late into fall. This extended photosynthetic period allows it to shade out native understory plants, preventing their growth and regeneration.
• Nutrient Cycling: Studies suggest that buckthorn can alter soil nitrogen levels, potentially benefiting its own growth while disadvantaging native species adapted to lower nitrogen environments.
• Allelopathy: There is evidence that buckthorn may release chemicals into the soil that inhibit the growth of other plants, though research on this is ongoing.
• Wildlife Impact: While birds consume the berries, the nutritional value and laxative effect of the fruit may not be ideal for their long-term health compared to native berry sources. The dense thickets also provide poor habitat for many native bird species that rely on open understories for nesting and foraging.
• Erosion: In some areas, dense buckthorn stands can prevent the establishment of a diverse native understory, potentially leading to increased soil erosion in certain conditions, especially on slopes.

Identification Features:

• Leaves: Oval to elliptic, finely toothed, dark green, 1-2.5 inches long, often arranged oppositely or sub-oppositely along the stem. They have distinctive arching veins that curve towards the tip.
• Stems/Bark: Young stems are smooth and grayish-brown. Older bark is rougher, fissured, and dark. A diagnostic feature is the thorn at the end of many twigs. When a small piece of bark is scraped away, the inner bark often reveals an orange layer.
• Flowers: Small, inconspicuous, greenish-yellow, with four petals, appearing in clusters in leaf axils in late spring.
• Fruit: Pea-sized, round, black drupes (berries) that ripen in late summer to fall. They contain 3-4 seeds.

Control and Management:

Management strategies for Common Buckthorn vary depending on the size of the infestation and the surrounding ecosystem.

• Manual Removal: Small plants can be pulled by hand, especially when the soil is moist. Tools like "weed wrenches" can be effective for larger saplings.
• Cutting: Cutting larger shrubs and trees at the base is often done, but regrowth from the stump is common. This method is usually followed by herbicide application to the cut stump to prevent resprouting.
• Herbicide Application: Foliar sprays are used for widespread infestations, while cut-stump treatments are effective for individual larger plants. Timing is crucial, often in late fall when native plants are dormant but buckthorn is still actively photosynthesizing.
• Prescribed Fire: In fire-adapted ecosystems, controlled burns can be used to manage buckthorn, often in conjunction with other methods.

Numerous resources are available from university extension offices, state natural resource departments, and conservation organizations that provide detailed guides and best practices for buckthorn identification and control. These resources often include photographic keys, seasonal timing recommendations, and information on local regulations.

Buckthorn (Medicinal Uses)

While the term "buckthorn" often conjures images of invasive plants, it's important to recognize that other species within the Rhamnaceae family, or even distantly related plants, are also referred to as buckthorn and have historical or current medicinal uses. The most prominent example is Sea Buckthorn (Hippophae rhamnoides), which is entirely different from the invasive Common or Glossy Buckthorns. Sea Buckthorn is a native plant to Europe and Asia and is renowned for its highly nutritious berries.

Another historically significant medicinal buckthorn is Cascara Sagrada (Frangula purshiana, formerly Rhamnus purshiana), native to western North America. Its dried bark was traditionally used as a laxative. However, its use has declined due to concerns about potential side effects and the availability of safer alternatives.

This section will focus primarily on the beneficial aspects associated with certain types of buckthorn, particularly Sea Buckthorn, as it is the most widely recognized for its health-promoting properties.

Sea Buckthorn (Hippophae rhamnoides)

Sea Buckthorn is a thorny shrub known for its vibrant orange-yellow berries. These berries are packed with an impressive array of nutrients and bioactive compounds.

Buckthorn Benefits (Specifically Sea Buckthorn):

The benefits attributed to Sea Buckthorn are largely due to its rich nutritional profile.

• Rich in Vitamins and Antioxidants: Sea Buckthorn berries are exceptionally high in Vitamin C (much higher than oranges), Vitamin E, Vitamin K, and several B vitamins. They also contain carotenoids (like beta-carotene and lycopene), flavonoids, and phenolic compounds, all of which are powerful antioxidants.
• Omega Fatty Acids: Unique among fruits, Sea Buckthorn contains all four omega fatty acids: Omega-3, Omega-6, Omega-7 (palmitoleic acid), and Omega-9. Omega-7 is particularly noted for its potential benefits for skin and mucous membranes.
• Skin Health: Due to its vitamin, antioxidant, and omega fatty acid content, Sea Buckthorn oil is widely used in cosmetics and skincare products. It's often promoted for its ability to support skin hydration, elasticity, and regeneration, potentially aiding in the management of conditions like eczema, psoriasis, and acne, as well as wound healing.
• Digestive Health: The antioxidants and anti-inflammatory compounds may support a healthy digestive tract. Some traditional uses include soothing stomach ulcers.
• Cardiovascular Health: The flavonoids and antioxidants may contribute to cardiovascular well-being by helping to manage cholesterol levels and reduce oxidative stress.
• Immune Support: High Vitamin C content and other immune-modulating compounds can support the body's immune system.
• Mucous Membrane Support: Omega-7 fatty acids are believed to be beneficial for the health and integrity of mucous membranes throughout the body, including the eyes, mouth, and digestive and genitourinary tracts. This has led to its use for conditions like dry eyes or vaginal dryness.

Buckthorn Supplement (Sea Buckthorn):

Sea Buckthorn is available in various supplement forms:

• Berry Juice/Puree: A direct way to consume the fruit, providing a broad spectrum of nutrients.
• Oil (Seed Oil or Fruit Oil): Concentrated forms of the fatty acids and fat-soluble vitamins. Seed oil is richer in Omega-3 and Omega-6, while fruit oil is higher in Omega-7 and carotenoids.
• Capsules/Softgels: Convenient forms of the oil or powdered berry extract.
• Topical Creams/Serums: For skin application, utilizing the oil's beneficial properties.

Buckthorn Dosage (Sea Buckthorn):

Dosage for Sea Buckthorn supplements can vary significantly based on the form, concentration, and the specific condition being addressed. There is no universally established recommended daily allowance.

• General Wellness: For general health support, doses might range from 500 mg to 2 grams of oil per day, often split into multiple doses.
• Specific Conditions (e.g., skin issues, dry eyes): Higher doses might be suggested, sometimes up to 3-6 grams of oil per day, but this should ideally be guided by a healthcare professional.
• Juice: If consuming juice, follow product-specific recommendations, as concentration varies.

It's always advisable to start with a lower dose and gradually increase it, observing how your body responds. Consulting a healthcare provider or a qualified nutritionist before beginning any new supplement regimen is recommended, especially for pregnant or nursing individuals, those with pre-existing medical conditions, or those taking other medications.

Buckthorn Side Effects (Sea Buckthorn):

Sea Buckthorn is generally considered safe for most people when consumed in food amounts or as a supplement for a limited time. Potential side effects are usually mild and uncommon.

• Digestive Upset: Some individuals might experience mild digestive issues like diarrhea or stomach upset, particularly with high doses of oil or juice, due to its laxative properties in some individuals.
• Blood Pressure: There's some theoretical concern that large amounts might affect blood pressure, though evidence is limited. Those with blood pressure conditions should exercise caution.
• Blood Clotting: Due to its Vitamin K content, which plays a role in blood clotting, individuals on anticoagulant medications (blood thinners) should consult their doctor before using Sea Buckthorn, as it could potentially interfere with these medications.
• Allergic Reactions: As with any natural product, allergic reactions are possible, though rare.

Buckthorn Natural Sources (Sea Buckthorn):

The primary natural source of Sea Buckthorn's beneficial compounds is its berries. These can be harvested directly from the plant if available, or purchased fresh, frozen, or as juice from specialty food stores or online retailers. The oil is extracted from both the seeds and the pulp of the berries.

Invasive Species: Common Buckthorn

As highlighted earlier, the term "buckthorn" frequently refers to invasive species like Common Buckthorn (Rhamnus cathartica) and Glossy Buckthorn (Frangula alnus). It's crucial to differentiate these from the beneficial Sea Buckthorn. The invasive buckthorns have virtually no beneficial uses in their introduced range and are, in fact, detrimental to native ecosystems.

Why are they considered invasive?

• Aggressive Growth: They grow quickly and form dense thickets that outcompete native vegetation.
• Early Leaf-out/Late Leaf-drop: Their extended growing season gives them a competitive advantage for sunlight.
• Prolific Seed Production: They produce abundant berries, which are consumed and dispersed by birds, leading to rapid spread.
• Adaptability: They tolerate a wide range of soil and light conditions.
• Lack of Natural Controls: In their introduced ranges, they often lack the natural predators, diseases, or herbivores that keep their populations in check in their native habitats.

Buckthorn Uses (Invasive Species):

In their native Eurasian range, certain buckthorn species might have minor uses such as hedges or as a source of dye from their berries or bark. However, in North America, where Common and Glossy Buckthorn are invasive, their "uses" are overwhelmingly negative:

• Ecological Degradation: They degrade forests, prairies, and wetlands by reducing biodiversity.
• Economic Impact: They can reduce timber value, make land less productive for agriculture or recreation, and incur significant costs for control and removal.
• Habitat Alteration: They provide poor-quality habitat for native wildlife, disrupting food chains and nesting sites.

It is important to reiterate that any discussion of "beneficial buckthorn" in a North American context, particularly relating to health supplements, almost exclusively refers to Sea Buckthorn, not the invasive Rhamnus cathartica or Frangula alnus. Consuming berries from invasive buckthorn species is not recommended due to their strong laxative effect and potential for other unknown compounds.

Fall is a Great Time to Find Buckthorn | Lincoln County, WI

The timing of buckthorn identification and control is critical, and fall presents a unique window of opportunity, as highlighted by numerous conservation groups, including those in Lincoln County, WI. This practical insight underscores the distinct characteristics of invasive buckthorn species.

Why Fall is Ideal for Identification and Control:

• Persistent Green Foliage: Unlike most native deciduous trees and shrubs that drop their leaves after the first hard frost, invasive buckthorn species (Common and Glossy) tend to retain their leaves much longer, often well into late fall or even early winter. This makes them stand out prominently as green patches in an otherwise dormant, brown landscape. This visual contrast is an excellent identifier for spotting infestations that might be camouflaged during the summer months.
• Sap Flow Reduction: In the fall, as plants prepare for winter dormancy, their sap flow decreases. This is particularly relevant for chemical control methods. Applying herbicides to cut stumps in late fall allows the plant to draw the herbicide down into its root system more effectively, leading to better kill rates and reduced resprouting compared to treatments applied during active growth periods.
• Accessibility: With other vegetation dying back, access to buckthorn plants can be easier. The ground may also be firmer than in spring, making manual removal or equipment use more feasible.
• Reduced Impact on Native Plants: Many native species are dormant in the fall, minimizing the risk of accidental damage or herbicide exposure to desirable plants during control efforts.

Practical Implications for Landowners:

For anyone dealing with buckthorn on their property, fall offers a strategic advantage.

1. Survey Your Property: Walk your property in October and November. Look for those tell-tale green shrubs and small trees that are still holding their leaves. This is the easiest way to identify buckthorn presence and gauge the extent of the infestation.
2. Plan Your Attack: Once identified, you can plan your removal strategy. For smaller plants, manual pulling can still be effective. For larger shrubs and trees, consider the "cut-stump" method where you cut the plant near the ground and immediately apply a small amount of herbicide (like glyphosate or triclopyr, following label instructions carefully) to the cut surface. This prevents resprouting.
3. Community Resources: Local conservation departments, university extension services, and community groups often provide workshops, equipment loans (like weed wrenches), or volunteer opportunities for buckthorn removal. They can also offer specific herbicide recommendations and application techniques suitable for your region and soil type.

Understanding these seasonal cues is a prime example of how distinguishing between different types of buckthorn – the invasive ecological threat versus the beneficial medicinal plant – is not just an academic exercise but a practical necessity for environmental stewardship and personal health decisions.

Comparison: Invasive Buckthorn vs. Sea Buckthorn

To summarize the critical distinctions, here's a comparison table between the two main categories of plants referred to as "buckthorn."

This table clearly illustrates the divergent nature and impact of plants that share a common name.

FAQ

Is buckthorn good for anything?

Yes, but it depends entirely on which "buckthorn" you are referring to. Sea Buckthorn (Hippophae rhamnoides) is highly beneficial, known for its nutrient-rich berries and oils used in supplements, food, and skincare. Its benefits include high vitamin C and E content, antioxidants, and all four omega fatty acids, supporting skin health, immune function, and cardiovascular wellness.

However, Common Buckthorn (Rhamnus cathartica) and Glossy Buckthorn (Frangula alnus), which are invasive species in North America, are generally not considered "good for anything" in their introduced range. They degrade native ecosystems, outcompete desirable plants, and provide poor habitat for wildlife. Their berries are mildly toxic and have a strong laxative effect, making them unsuitable for human consumption.

Can humans eat buckthorn?

Again, this depends on the species. Humans can eat Sea Buckthorn berries, which are tart but highly nutritious. They are consumed fresh, juiced, or processed into oils and other products. These berries are a superfood known for their health benefits.

Humans should not eat the berries of invasive Common or Glossy Buckthorn. These berries are known for their strong laxative effect and are considered mildly toxic. While not typically lethal, consuming them can cause significant gastrointestinal distress, including severe diarrhea, nausea, and vomiting.

Should I remove buckthorn from my yard?

If you have invasive Common Buckthorn or Glossy Buckthorn in your yard, it is generally recommended to remove it. These species are detrimental to local ecosystems:

• They outcompete native plants for light, water, and nutrients, reducing biodiversity.
• They alter soil chemistry.
• They provide low-quality habitat for native wildlife.
• Their dense growth can make areas impassable and reduce the aesthetic and ecological value of your property.

Removing them helps restore ecological balance, allows native plants to thrive, and improves the overall health of your local environment. Fall is often an ideal time for removal efforts due to their persistent green leaves and effective herbicide uptake for cut-stump treatments.

Conclusion

The term "buckthorn" is a source of considerable confusion due to its application to various plant species with vastly different characteristics and impacts. It is critical to differentiate between the invasive species, such as Common Buckthorn (Rhamnus cathartica) and Glossy Buckthorn (Frangula alnus), and the beneficial Sea Buckthorn (Hippophae rhamnoides). While the former are ecological threats requiring active management and removal, the latter is a valuable source of nutrients and bioactive compounds with potential health benefits. For curious readers seeking clear, trustworthy information, understanding this distinction is paramount for making informed decisions, whether concerning land management or dietary supplementation. Always verify the specific species when encountering "buckthorn" in any context to avoid misinterpreting its nature or potential effects.