Buckthorn (Frangula): What Every Gardener Should Know
If you’ve ever wandered through a garden center and spotted a shrub labeled buckthorn, you might be looking at a member of the Frangula genus. These perennial shrubs have a complex story that every gardener should understand before bringing one home.
What Exactly Is Buckthorn?
Frangula, commonly known as buckthorn, is a genus of multi-stemmed woody shrubs that typically grow between 13 to 16 feet tall. These perennial plants are characterized by their multiple stems that arise from or near the ground, though they can sometimes grow taller or develop a single stem depending on environmental conditions.
The plants produce small, inconspicuous flowers and dark berries, with simple oval-shaped leaves that create a relatively understated appearance in the landscape.
Where Does Buckthorn Come From?
Here’s where things get interesting (and a bit complicated). Frangula has a rather mixed native status across North America. It’s native to Puerto Rico, but in Hawaii, it’s considered a non-native species that was introduced and now reproduces on its own in the wild. For Canada and the lower 48 states, the native status is undefined, which should raise some eyebrows for conscientious gardeners.
You can find Frangula growing across an impressively wide range of locations, from Alabama to Wyoming, and from British Columbia to Prince Edward Island. This extensive distribution includes most U.S. states and Canadian provinces.
The Garden Dilemma: To Plant or Not to Plant?
This is where buckthorn becomes a bit of a gardening puzzle. While some species in this genus can serve as landscape shrubs, their tendency to reproduce spontaneously and spread beyond cultivation raises concerns. The fact that Frangula is already established as a non-native reproducer in Hawaii suggests it has the potential to become problematic elsewhere.
From a design perspective, these shrubs can fill the role of a medium-sized background plant or screening shrub. However, their relatively plain appearance and uncertain ecological impact make them less than ideal choices for most garden situations.
Wildlife Considerations
Frangula does provide some wildlife value, though it’s not particularly impressive:
- Large animals get about 5-10% of their diet from these plants but rarely use them for cover
- Small mammals derive only 2-5% of their diet from buckthorn and use it sparingly for shelter
- Terrestrial birds also get 5-10% of their diet from these shrubs but don’t commonly use them for cover
While it’s not completely without value to wildlife, buckthorn isn’t exactly a wildlife magnet compared to many native alternatives.
Better Alternatives for Your Garden
Given the uncertain invasive status and the complex native/non-native situation with Frangula, most gardeners would be better served by choosing native shrubs that provide similar landscape functions without the ecological concerns.
Consider these native alternatives instead:
- Native viburnums for multi-season interest and superior wildlife value
- Native elderberries for food production and pollinator support
- Regional native dogwoods for stunning flowers and bird-friendly berries
- Native serviceberries for edible fruit and excellent fall color
The Bottom Line
While Frangula isn’t currently listed as invasive everywhere, its track record of spontaneous reproduction beyond cultivation and unclear native status make it a questionable choice for environmentally conscious gardeners. With so many beautiful native shrubs available that provide better wildlife value and zero risk of ecological disruption, why take the chance?
If you’re set on buckthorn for a specific reason, proceed with caution, monitor it closely for signs of spreading, and consider whether a native alternative might serve your needs just as well—or better.
