Alnus cordata subsp. neapolitana
Neapolitan alder
A fast-growing , deciduous tree wto around 15m in height in the right conditions, with heart-shaped dark green leaves, glossy on the top, and horizontal growth on the side of the branches. Leaves remain green and on the tree well into autumn. Yellow catkins appear on both male and female trees in the spring, followed by clusters of pineapple-shaped greenish-brown fruits. Small, winged seeds are dispersed in winter. Makes a suitable windbreak and screen for large, open areas
Buy this plant
Size
Ultimate height
Higher than 12 metresTime to ultimate height
20–50 yearsUltimate spread
4–8 metresGrowing conditions
Moisture
Moist but well–drained, Poorly–drainedpH
Acid, Alkaline, NeutralColour & scent
| Stem | Flower | Foliage | Fruit | |
| Spring | Yellow | Green | ||
|---|---|---|---|---|
| Summer | Green | Brown Green | ||
| Autumn | Green Yellow | Brown Green | ||
| Winter |
Position
- Full sun
Aspect
East–facing or South–facing or West–facing
Exposure
Exposed or Sheltered Hardiness
H6Botanical details
- Family
- Betulaceae
- Native to GB / Ireland
- No
- Foliage
- Deciduous
- Habit
- Spreading branched
- Genus
Alnus are vigorous deciduous trees and large shrubs with rounded leaves and often conspicuous catkins in winter
- Name status
Correct
- Plant range
- S Italy
How to grow
Cultivation
Thrives in fertile, moist but well-drained soil, but tolerates a range of conditions including poor drainage. Can make a fast-growing screen on wet sites
Propagation
Propagate by seed or by hardwood cuttings
Suggested planting locations and garden types
- Architectural
- Low Maintenance
- Hedging and screens
Pruning
Pests
May be susceptible to alder sucker, alder leaf beetle and leaf-mining sawflies
Diseases
May be susceptible to phytophthora root rots and honey fungus
Get involved
The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.