Alder buckthorn
Frangula alnus · Rhamnaceae
📷 Stefan.lefnaer · CC BY-SA 4.0
⚠️ Bourdaine : glucosides anthracéniques. Chiens/chats : diarrhée, crampes. Humains : troubles digestifs, diarrhée importante par ingestion d'écorce ou baies.
The gardener's calendar
In autumn, ease off feeding and take the chance to clean up around alder buckthorn and prepare for winter.
ID card
- Scientific name
- Frangula alnus
- Family
- Rhamnaceae
- Form
- Shrub
- Foliage
- Deciduous
- Flowering
- May to June, whitish-green flowers
- Adult size
- 3 to 4 m in height
- Growth
- Fast
- Hardiness
- Very hardy (−25 °C)
- Origin
- Europe, northwestern Asia
- Soil type
- Humid, tolerant, slightly acidic to neutral
✓ Taxonomy verifiedSource: AI estimate · hardiness: reliability high.
Expert tips
The key tip
Frangula accepts partial shade and compacted soils. It's a very easy shrub once planted.
The common mistake
Babying it too much: most gardeners prune too short or too often, which leaves it bare.
The pro's trick
Let it develop freely for the first two years, then a simple shape trim in July is all it needs.
Seasonal watch
In autumn, if summer was very dry, water moderately to help fruiting.
Care
Light exposure
Buckthorn prefers a partially shaded situation, though it also tolerates direct sun exposure. It adapts remarkably well to woodlands and forest edges. A semi-shaded exposure promotes balanced growth and dense foliage.
Watering
Keep the soil regularly moist, especially during the first year after planting and during dry periods. Buckthorn tolerates wet soils or even temporarily flooded conditions, making it ideal for low-lying areas. However, avoid prolonged waterlogging in well-drained soil.
Soil and planting
Plant in autumn or spring in fertile, moist, slightly acidic soil. This species adapts to almost all soil types but prefers fresh, well-structured ground. Incorporate well-decomposed compost when planting to encourage root establishment.
Pruning and maintenance
Practice light pruning after flowering to maintain an attractive shape and remove dead or damaged branches. Buckthorn tolerates more severe pruning if necessary. Annual finishing pruning is usually sufficient for this fast-growing shrub.
Nutrition
No fertilizer is strictly necessary if the soil is rich in organic matter. In poor soil, an annual application of well-decomposed compost at the base is plenty. Avoid nitrogen-rich fertilizers that would encourage excessive vegetative growth at the expense of flowering.
Disease resistance
Buckthorn is very hardy and rarely susceptible to diseases. Phytosanitary treatment is generally unnecessary. Simply watch for possible minor pests in case of prolonged water stress, though this remains extremely rare.
Did you know?
Buckthorn was once widely exploited to produce a yellow dye and black colorant (after fermentation of the bark), particularly prized by medieval weavers. In traditional European phytotherapy, its bark was used, but this practice requires expertise to properly identify and use; it's best to consult a professional before any use. Its common name "buckthorn" comes from the Germanic "Bernstein," a reference to its beautiful amber color.
Where to buy it
Best planted in autumn so the roots settle in before summer, or in early spring once the frost has passed. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, October, November.
Add this plant to my garden →Plants from the same family
- BuckthornRhamnus alaternus
- JujubeZiziphus jujuba
- Indian jujubeZiziphus mauritiana
- BlueblossomCeanothus thyrsiflorus
- Feltleaf ceanothusCeanothus arboreus
- Point Reyes ceanothusCeanothus gloriosus
Tips generated and checked by Viridia — adapt them to your local climate.