Most buckthorn varieties are easy-to-grow shrubs that make great privacy screens, backdrops, or hedges, thanks to their dense habit and lustrous, dark-green foliage. Steer clear of several types of buckthorn, though. Common or European buckthorn and glossy or alder buckthorn are invasive species that are illegal to sell and plant in many areas. Noxious weeds, these rogue buckthorns degrade woodlands and wildlife habitats; prevent native plants from accessing nutrients, light and moisture; and are difficult to eradicate.
Best Uses for Buckthorn
Buckthorn makes an excellent hedge plant and can easily be maintained at a specific size with an annual pruning. Call on this deciduous shrub to screen the view into a neighboring yard. Employ it as a leafy living wall used to enclose a patio. Plant a row of buckthorn along a lackluster garage wall, transforming the sterile area into a backyard habitat.
Buckthorn produces berries in summer, making it a stopping place for birds. Pair buckthorn with other berry-producing shrubs to create a bountiful backyard buffet. Try the following easy-to-grow bird-friendly shrubs as companion plants: dwarf cranberry bush viburnum, beautybush (a member of the honeysuckle family), and Oregon grape-holly.
Narrow Leaf Buckthorn
Rhamnus frangula 'Asplenifolia' is a deciduous shrub with narrow leaves that offer a finely textured appearance. This variety grows 10 to 12 feet high and 6 to 10 feet wide. It should not be planted in the Midwest where it is considered invasive. Zones 2-7
Buckthorn Care Must-Knows
Buckthorn is an adaptable shrub. It grows best in full sun or part shade and moist, well-drained soil. It prefers consistent moisture, but it tolerates a variety of soil types and environments—including dry foundation planting areas and planting spots that receive just a few hours of sunlight a day. Plant buckthorn in spring, and water it regularly during the first growing season. After establishing a strong root system, it will better tolerate dry conditions.
Prune buckthorn as needed in spring based on the type. Fine Line buckthorn displays an upright, columnar habit and rarely requires pruning. Narrow leaf buckthorn exhibits an open habit and benefits from annual pruning to maintain a dense branching structure.
Watch for a variety of problems that include cankers, caterpillars, Japanese beetles, leaf spots, rust, and scale. The roots may be attacked by nematodes.
Fine Line Fern Leaf buckthorn
Rhamnus frangula 'Ron Williams' grows 5 to 7 feet tall and 2 feet wide. It adds texture and shape to the garden with its narrow columnar habit and lacy foliage. This variety should not be planted in the Midwest where it is considered invasive. Zones 3-7.
Variegated Italian buckthorn
Rhamnus alternus is an evergreen shrub that bears attractive gray-green foliage edged in white. It makes a great hedge thanks to its dense habit. It's also good as a topiary subject or patio tree. This variety grows 15 feet tall and 12 feet wide. Zones 7-9