American hornbeam
Carpinus caroliniana · Betulaceae
The gardener's calendar
In autumn, ease off feeding and take the chance to clean up around american hornbeam and prepare for winter.
ID card
- Common name
- Ironwood, American Hornbeam
- Family
- Betulaceae
- Foliage
- Deciduous
- Flowering
- Spring (April-May), insignificant flowers
- Adult size
- 8 to 12 m tall × 6 to 8 m wide
- Growth
- Slow to moderate
- Hardiness
- Excellent (down to -25 °C)
- Origin
- North America (Canada and United States)
- Soil type
- Fresh, well-drained soils, tolerates acidity and moisture
Care
Watering
Water regularly during the first year after planting to promote root establishment. Once established, ironwood tolerates dry periods well but appreciates moderate soil moisture. During prolonged drought, water deeply once or twice a week.
Exposure
Place ironwood in full sun or light shade. It prefers sunny locations to develop a harmonious habit and beautiful fall color. It also adapts well to open woodlands.
Soil and drainage
This hornbeam appreciates fresh, well-drained soils. It tolerates acidic, neutral, and slightly alkaline soils. Enrich the planting hole with compost or organic matter. Avoid overly compacted or chronically waterlogged soils.
Pruning
No strict pruning is necessary; ironwood naturally adopts a balanced, well-branched form. Simply remove dead, diseased, or crossing branches in spring or late winter. Excessive pruning slows its already slow growth.
Fertilizer
An annual application of compost or organic matter on the surface in spring is more than sufficient. Avoid overly rich fertilizers that promote excessive growth and unbalanced form. No fertilizer is necessary in fertile soil.
Diseases and pests
Ironwood is very robust and rarely affected by serious diseases. Occasionally watch for aphids or small insects, but good vigor is generally enough to control them. In excessively humid conditions, thin the canopy to prevent fungal problems.
Did you know?
The ironwood gets its name from the exceptional density of its wood, among the densest in North America: it sinks in water and was once used by indigenous peoples to make tools and weapons. This tree was a precious symbol of strength in North American landscape literature and remains highly valued by modern landscapers for its understated elegance and resilience.
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
- Silver birchBetula pendula
- Grey alderAlnus incana
- Dwarf birchBetula nana
- European Hop-hornbeamOstrya carpinifolia
- Turkish hazelCorylus colurna
- Italian AlderAlnus cordata
Tips generated and checked by Viridia — adapt them to your local climate.