Walnut tree is a large deciduous tree that can grow up to 40 m tall.It has a wide, spreading canopy and deeply furrowed, dark brown bark. The leaves are alternately arranged, compound, and have toothed margins. The flowers are borne in catkins, and the fruit is a nut enclosed in a green, leathery husk. Walnut trees are native to the temperate regions of the Northern Hemisphere.
Related plant:
English Walnut
Related plant:
Black Walnut Tree
About soil condition, a walnut tree needs deep, well-drained soils with a pH of 6.0 to 7.0. If the soil is too alkaline, the tree may suffer from chlorosis, which is when the leaves turn yellow because the tree can't take up enough iron.
Like the other trees, walnut trees need sunlight to grow. They can grow in partial shade, but they need at least six hours of direct sunlight each day to produce a good crop of nuts. If you have a walnut tree that is not getting enough sun, you may need to prune it to open up the canopy and let more light in.
The temperature condition necessary for germination and growth of the walnut tree is quite specific. Thetree requires a relatively cool climate during the winter months in order to break dormancy and begin new growth in the spring. If the winter temperatures are too warm, the tree will not produce the necessary growth hormone needed for new cell production. Conversely, if the winter temperatures are too cold, the tree will not produce the necessary enzymes needed for germination. The ideal temperature range for the walnut tree is between 35 and 45 degrees Fahrenheit.
Ideal humidity condition for this plant is 60% to 70%. If the humidity is too low, the leaves will start to turn yellow and drop off. If the humidity is too high, the leaves will start to turn brown and drop off.
Mentioning fertilizer, this type of plant food is important to a walnut tree's growth. Applying fertilizer to the roots of a walnut tree encourages growth and helps the tree to reach its full potential. This is due to the nutrients in the fertilizer seeping into the roots and being absorbed by the tree. Fertilizer helps the tree to grow strong and healthy, and also encourages fruit production.
Pruning walnut trees is a very important part of their care. Walnut trees need to be pruned in order to keep them healthy and encourage new growth. When pruning walnut trees, it is important to remove any dead or dying branches. It is also important to thin out the tree so that sunlight can reach the inner branches.
Propagation of walnut trees is best accomplished by grafting or rooting hardwood cuttings taken from the desired tree. The best time to take cuttings is in late winter before new growth begins. Walnut trees can also be grown from seed, but this is a slower process and the resulting trees are often not true to the parent tree.
Usually, the plant growth rate studies report an average annual increase in diameter of 10 to 20 millimeters (mm). However, the range observed in individual trees is large, with some trees growing as little as 2 mm annually and others as much as 60 mm. In a study of black walnut trees in Ohio, the average annual diameter growth rate for all trees was 12 mm, with the fastest growers adding 34 mm per year and the slowest losing 2 mm annually.
Common problems for this kind of plant are aphids, caterpillars, and mites. These pests can cause the leaves to turn yellow and curl up. If the infestation is bad enough, it can kill the tree. To prevent these pests from attacking your tree, make sure to keep the area around the tree clean and free of debris.
Source:
Black Walnut | Department of Horticulture - University of Kentucky
Germination of Walnuts | Horticulture and Home Pest News
Managing black walnut forests | UMN Extension
