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[1, 11]. Prefers a slightly alkaline soil[200]. 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[269]. 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[269]. 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[269]. A very ornamental and fast growing plant[1, 200], 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[269]. Good seed crops are usually produced every other year, though some plants fruit well annually whilst others produce god crops every third year[269]. 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[183, 269]. There are breeding programmes that are seeking to develop cultivars with thinner shells[226]. Trees in the wild commence bearing seeds when about 12 years old[227]. 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[269]. Trees do not fruit very freely in Britain unfortunately[1, 11]. They grow well in the eastern half of the country but often do not thrive in the west[98]. Trees have been extensively planted for timber in parts of C. and E. Europe[50]. This species hybridizes with J. regia[149], 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[1, 11, 269]. 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[1, 11]. Flower initiation depends upon suitable conditions in the previous summer[200]. 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[200]. 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[269]. 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[200]. 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[18, 20, 159]. The roots also produce substances that are toxic to many plant species, especially apples (Malus species), members of the Ericaceae, Potentilla spp and the white pines (certain Pinus spp.)[200]. Beans, peas and tomatoes are also particularly sensitive to these secretions and will not grow in the rooting zone[200]. Trees cast quite a dense shade so, along with their other anti-social tendencies, are not very friendly trees for a woodland garden[K]. The bruised leaves have a pleasant sweet though resinous smell[245]. Special Features: Attracts birds, North American native, Inconspicuous flowers or blooms. The plant is heat tolerant in zones 9 through 5. (Plant Hardiness Zones show how well plants withstand cold winter temperatures. Plant Heat Zones show when plants would start suffering from the heat. The Plant Heat Zone map is based on the number of "heat days" experienced in a given area where the temperature climbs to over 86 degrees F (30°C). At this temperature, many plants begin to suffer physiological damage. Heat Zones range from 1 (no heat days) to 12 (210 or more heat days). 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 (form - tree, shrub etc. and size shown above) 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 [1-2]. The root pattern is a tap root similar to a carrot going directly down [1-2].

Carbon Farming

• Industrial Crop: Dye  Botanical dyes replacing synthetic dyes (known as heavy polluters).
• Management: Standard  Plants grow to their standard height. Harvest fruit, seeds, or other products. Non-Destructive management systems.
• Other Systems: Strip intercrop  Tree crops grown in rows with alternating annual crops.
• Regional Crop  These crops have been domesticated and cultivated regionally but have not been adopted elsewhere and are typically not traded globally, Examples in this broad category include perennial cottons and many nuts and staple fruits.
• Staple Crop: Protein-oil  (16+ percent protein, 16+ percent oil). Annuals include soybeans, peanuts, sunflower seeds. Perennials include seeds, beans, nuts, and fruits such as almond, Brazil nut, pistachio, walnut, hazel, and safou.