Buckthorn: A Complex Genus That Requires Careful Consideration
When someone mentions buckthorn in gardening circles, you’re likely to get mixed reactions. That’s because the genus Rhamnus is like a box of chocolates – you never know what you’re going to get, and some varieties are definitely better than others for your garden and local ecosystem.
What Exactly Is Buckthorn?
Rhamnus, commonly known as buckthorn, is a diverse genus of perennial shrubs that can be found across North America and beyond. These multi-stemmed woody plants typically grow to heights of 13-16 feet, though they can sometimes stretch taller or remain more compact depending on growing conditions. With their several stems arising from or near the ground, buckthorns have the classic shrub architecture that many gardeners appreciate.
Where Does Buckthorn Grow?
The distribution of Rhamnus species is impressively wide, spanning across most of North America. You’ll find various buckthorn species growing from Alberta to Alabama, from British Columbia to Newfoundland, and in virtually every U.S. state including Alaska. This extensive range hints at the genus’s remarkable adaptability to different climates and growing conditions.
The Good, The Bad, and The Complicated
Here’s where things get interesting – and why you need to do your homework before adding any buckthorn to your landscape. The Rhamnus genus includes both native North American species that support local wildlife and notorious invasive species that can wreak havoc on natural ecosystems.
Some buckthorn species are native treasures that provide valuable habitat and food sources for birds and other wildlife. Their small, white to greenish flowers attract various pollinators including bees and small insects, while their berries feed numerous bird species throughout fall and winter.
However, certain non-native buckthorn species, particularly common buckthorn (Rhamnus cathartica) and glossy buckthorn (Rhamnus frangula), are among the most problematic invasive plants in many regions. These aggressive spreaders can dominate understory areas, outcompete native plants, and alter soil chemistry.
Should You Plant Buckthorn?
The short answer? It depends entirely on which species you’re considering. Before planting any buckthorn, you absolutely must:
- Identify the exact species you’re considering
- Research whether that specific species is native to your region
- Check local and state invasive species lists
- Consult with local native plant societies or extension services
If you’re interested in the benefits that native buckthorn species can provide – such as wildlife habitat, erosion control, and naturalized landscaping – make sure you’re choosing a species that’s actually native to your area.
Growing Conditions and Care
Most buckthorn species are remarkably adaptable and low-maintenance once established. They generally thrive in USDA hardiness zones 3-8, though this varies by species. These tough shrubs can handle:
- Various soil types and pH levels
- Full sun to partial shade conditions
- Both moist and relatively dry soils
- Urban pollution and harsh growing conditions
If you do plant a native buckthorn species, care is typically minimal. Occasional pruning may be needed to maintain shape or remove dead wood, and young plants may benefit from regular watering during their first growing season.
Wildlife and Pollinator Benefits
Native buckthorn species can be valuable additions to wildlife-friendly gardens. Their flowers provide nectar for various small pollinators, while their berries are important food sources for birds, especially during fall migration and winter months. The dense branching structure also offers nesting sites and shelter for various bird species.
Landscape Design Role
In the right context, native buckthorn species can serve several landscape functions:
- Naturalized areas and wildlife gardens
- Erosion control on slopes
- Informal hedging or screening
- Background plantings in mixed shrub borders
The Bottom Line
Buckthorn’s reputation is complicated for good reason. While some species are valuable native plants worthy of garden space, others are ecological disasters waiting to happen. The key is education and careful species selection. When in doubt, consult with local experts and consider well-researched native alternatives that can provide similar benefits without the risk.
Remember: in the plant world, the devil is definitely in the details – and with buckthorn, those details matter more than most.
