Juglans regia – Common Walnut (southern Europe, N.Asia)
Habit: Medium-size tree with round crown, 10-15 (20) m tall, rarely larger here, 8-10 m wide; usually with short stem, often crooked; branches extended, occassionally overhanging, few twigs, little foliage, slow-growing, 30-40 cm a year.
Flowers: Monoecious, usually before leaves shoot from beginning to mid-May, male flowers in green-brown catkins, female ones are green cups, inconspicuous.
Fruits: Edible nuts, 2-3 cm long, covered by a green case, ripe in September.
Leaves: Pinnate, some 20-30 m long, shoots sensitive to late frost; medium-green, aromatic; falling in October to November.
Roots: Deep, tolerates floods, covering and careful paving; sensitive when transplanted; do not transplant once established.
Demands: Sunny to slightly shady, tolerates heat, likes warmth, somewhat frost hardy; good for urban areas, sensitive to wind.
Soil: Moderately dry to moist, slightly acidic to very alkaline, well drained, nutritious substrates, clay increases frost damage; moderately tolerant of salt.
Note: Cut back in late summer or autumn; later cutting causes great bleeding.
Hardiness: Zone 6a