Juglans nigra

Bloom Color: Unknown. Main Bloom Time: Early spring, Late spring, Mid spring. Form: Rounded.

Juglans nigra is a deciduous Tree growing to 30 m by 20 m at a fast rate.
It is hardy to zone 4 and is not frost tender. It is in flower from May to June, and the seeds ripen in October. The species is monoecious and is pollinated by Wind. The plant is self-fertile.
Suitable for: light , medium and heavy soils and prefers well-drained soil. Suitable pH: acid, neutral and basic soils. It cannot grow in the shade. It prefers moist soil.

Industrial Crop: Dye Management: Standard Other Systems: Strip intercrop Regional Crop Staple Crop: Protein-oil
Landscape Uses:Firewood, Aggressive surface roots possible, Specimen. Requires a deep well-drained loam and a sunny position sheltered from strong winds. Prefers a slightly alkaline soil. Plants are best suited to deep, rich, slightly acid or neutral soil, with good drainage, but will not succeed on infertile upland soil or on soils with poor drainage. The black walnut grows best areas with an annual precipitation from 30 to 130cm, an annual temperature in the range of 7 to 19°C and a pH from 4.9 - 8.2. The dormant plant is very cold hardy, but the young growth in spring, however, can be damaged by late frosts. The Black walnut is one of most valuable natural forest trees in the United States. A very ornamental and fast growing plant, it is sometimes cultivated in N. America for its edible seed. Whilst potential yields of 7.5 tonnes per hectare have been postulated, it is more feasible to expect annual yields of around 2.5 tonnes per hectare. Good seed crops are usually produced every other year, though some plants fruit well annually whilst others produce god crops every third year. The average weight of a seed from wild trees is about 17g, though there are many named varieties and the weight of their seeds varies from 20 - 30g. There are breeding programmes that are seeking to develop cultivars with thinner shells. Trees in the wild commence bearing seeds when about 12 years old. Black walnut trees mature their fruit rather generally throughout the plants natural range where there is a growing season of about 150 days and an average summer temperature of 16.5°C. Trees do not fruit very freely in Britain unfortunately. They grow well in the eastern half of the country but often do not thrive in the west. Trees have been extensively planted for timber in parts of C. and E. Europe. This species hybridizes with J. regia, some named cultivars have been developed from this cross for their seed. Plants produce a deep taproot which makes them very drought resistant when established, though they are intolerant of root disturbance. Seedlings should be planted out into their permanent positions as soon as possible and given some protection for their first winter or two since they are somewhat tender when young. Flower initiation depends upon suitable conditions in the previous summer. The flowers and young growths can be destroyed by even short periods down to -2°c, but fortunately plants are usually late coming into leaf. The black walnut is self-fertile, but the sequence of male and female blooming, called dichogamy, can and often does minimize chances of a tree shedding pollen on its own pistils. In different trees pollen may be shed before the receptivity period of female flowers, or at same time, or after pistil receptivity. For greatest possible nut production, plant trees of 2 or more cvs, as different cvs have overlapping pollen-receptivity periods and can pollinate each other. Any pruning should only be carried out in late summer to early autumn or when the plant is fully dormant otherwise wounds will bleed profusely and this will severely weaken the tree. Plants produce chemicals which can inhibit the growth of other plants. These chemicals are dissolved out of the leaves when it rains and are washed down to the ground below, reducing the growth of plants under the tree. The roots also produce substances that are toxic to many plant species, especially apples , members of the Ericaceae, Potentilla spp and the white pines . Beans, peas and tomatoes are also particularly sensitive to these secretions and will not grow in the rooting zone. Trees cast quite a dense shade so, along with their other anti-social tendencies, are not very friendly trees for a woodland garden. The bruised leaves have a pleasant sweet though resinous smell. Special Features:
Attracts birds, North American native, Inconspicuous flowers or blooms. The plant is heat tolerant in zones 9 through 5. .
At this temperature, many plants begin to suffer physiological damage. Heat Zones range from 1 to 12 .
For example Heat Zone. 11-1 indicates that the plant is heat tolerant in zones 11 through 1.) For polyculture design as well as the above-ground architecture information on the habit and root pattern is also useful and given here if available. The plant growth habit is a standard with a non-suckering single trunk . The root pattern is a tap root similar to a carrot going directly down .