Description
Juglans nigra – Black walnut
Short description: The black walnut from North America is the more imposing, faster-growing sister of the common walnut – with a broad, domed crown, deeply furrowed dark grey bark, and aromatic fruits with an intensely flavoured nut kernel. Its timber is among the most valuable hardwoods in the world. As a specimen tree for parks and large gardens, it creates strong, long-lasting accents.
- Growth approx. 1.10 m/year
- Trunk diameter up to 1–2.5 m
- Park tree in open position
- Beautiful decorative timber, easy to work, used for furniture
- Hardly at risk from browsing
- Fully hardy, but susceptible to late frost
- Fruit: edible + tasty
- Up to 250 years possible
- Deep-rooting
- Sun to partial shade
Climatic characteristics & site conditions: The black walnut is hardy down to –25 °C, making it suitable for all locations in Europe. It prefers deep, fresh, and well-drained soils, but tolerates drought better than the common walnut. It develops particularly well in the warmer sites of the Upper Rhine Plain, the Neckar Valley, and Franconia. Like all walnuts, it releases allelopathic substances that can inhibit the growth of neighboring plants.
Advantages: Very vigorous growth, impressive crown, valuable timber, more drought-tolerant than common walnut, hardy in all southern German locations, aromatic fruits.
Disadvantages: Not native, allelopathic – inhibits growth of neighbouring plants, requires a lot of space, fruits stain intensely and permanently, not a woody plant for small gardens, no ecological value for native insects.
