Walnut is a crop that can be grown not only in warm climates. Thanks to selection, many varieties have appeared that can easily tolerate frosts down to minus 30 degrees, such varieties are unpretentious and do not require much maintenance.
How to plant
Before planting, nut seedlings can be root-treated to make rooting easy. When placing a seedling in a pit, it is worth checking if the thickening after grafting is above the ground. Planting about 2 cm deeper than in the nursery because planting too deep results in weaker growth for the first time in years. The roots of the nut are spread on a small mound and buried, trampling the ground and watering abundantly. The trunk of the tree is tied to the stake with a soft material. If the winter is harsh, build an embankment up to 25 cm high around the trunk. Water should be abundant during dry springs.
In spring, all shoots should be shortened by a third and only good branches should be left on each shoot, and the rest should be removed. The recommended spacing between walnuts is 20 x 15 m, but in new orchards it is also possible to sow more densely at 10 x 10 m intervals. The walnut self-pollinates, but fertilization is not always successful. This is due to the separation of male and female flowers on the tree and different flowering times, which makes pollination difficult. For this reason, plant a pollinator such as Franquette or other pollinating plants nearby.
Reproduction of cuttings
In industrial production, only grafted nuts are grown. The fertility of these trees is much higher than that obtained from seeds. In Russia, nut propagation most often occurs by grafting in the spring, in March or April, but this grafting is different from the traditional grafting of fruit trees. Due to the cold climate in our country, neither budding nor traditional inoculation succeeds, because the callus of the nut is formed only at high temperatures, which are not available in our country.
Therefore, a vaccination method has been developed that is suitable for cold climates. Nuts are grafted by hand, in October, on a garden bed, and the resulting grafts are placed in boxes, and then covered with wet sawdust. The boxes should be left indoors at 26 ° C for approximately 18 days. After this time, callus is formed automatically, and the scion grows together with the stock. After the cuttings have warmed up, they must be transferred to a cool place and stored at a temperature of about 0 ° C until spring, when the seedlings can be planted in the ground.
The noble varieties known in Europe come from the walnut. In Poland, the first varieties were selected in 1991. The most popular and cultivated walnut varieties are: Albi, Apollo, Dodo, Frankett, Jupiter, Lake, Leopold, No. 17, Resovia, Seifersdorfer Runde, Silesia, Targo and Trumph. They are frost-hardy and yield high yields, and their fruits have a thin shell.
In young plants, it is enough to remove unnecessary lateral shoots from September to the end of October. An adult tree does not tolerate pruning, so only diseased or frozen branches are removed every 5-10 years in the fall. Very strong young shoots that grow vertically in the crown are the so-called wolves, and the shoots are weak or crossed.
If a cut is necessary, trim as little as possible, and then immediately apply a garden ointment to the wound, which accelerates scarring. The walnut has wood, the pruning of which causes the formation of weak points, that is, places favorable for the appearance of diseases and pests. Cutting nuts should not be done in the spring, as this will cause abundant juice from the wounds, which can lead to disease. It is also important that the land around the young trees is clean.