Selecting And Growing Walnuts

Press, Volume CVI, Issue 31088, 17 June 1966, Page 6

Selecting And Growing Walnuts

There is an old adage which goes like this:— “A woman, a dog, a walnut tree, the more you beat them the better they bear.” However, I have not found any reference or statistics which prove or disprove the above statement, but it is accepted that by beating the branches of a walnut in order to drop the crop the terminals are broken, thereby encouraging the formation of fruit spurs which bear the following year. A well-grown walnut tree may grow to 100 feet high. Both male and female flowers are borne, the former recognisable as pale yellow catkins and the latter growing in small groups on newly formed shoots.

The selection of variety, of which there is quite a number, is of considerable importance as it exerts a major influence on vital factors such as size, shape, kernel flavour, keeping qualities, commencement of spring growth, yield and resistance to disease.

Specimens can be grown from seeds, grafted or budded, the latter possessing the advantage over seedlings in that the fruit falls more readily in autumn. Gathering Seeds About now is an opportune time to gather seed which is best stored in boxes of moist peat. It then becomes necessary to ensure that the peat remains moist and is neither allowed to dry out nor is kept too wet. In spring the seed can be sown outside about one inch deep in a mixture of sand and peat giving frost protection. The seedling can be transplanted in autumn. The walnut tree, which is deep rooting, will grow in most soils, although it is inclined to be less long lived in the lighter ones, and requires good drainage. It is responsive to organic matter, calcareous soils of adequate depth and moisture retention. During the early formative years especially, the addition of extra phosphorous and potassium is relatively important. A suitable general fertiliser containing five parts sulphate of ammonia, 10 superphosphate, 10 potash at tbe rate of two pounds for small trees, seven pounds for medium sized trees and 15 to 20 pounds for the largest, would prove most beneficial. Spring frosts can be a real danger to young leaves and flowers, a two to three degree frost of a few hours’ duration being capable of considerable damage. Again, of importance during the first few years of the young walnut tree, is the task of building up a satisfactory framework which should be kept fairly open. To encourage earlier cropping by inducing fruiting spurs all laterals should be tipped after the five or six leaf stage has been reached. Incidentally, next time you are near one of these trees look at the terminal growths. Unlike the tips of other subjects they do not grow in the direction they start in. New growth each spring frequently arises from a bud inches back from the terminal bud and often from the underside; thus it is possible that it eventually extends horizontally after a few years. Although self-fertile variable flowering of male and female flowers may result in

either no fruit or poor pollination and for this reason far better results. are usually obtained where there is more than one tree in any one location. Unfavourable seasons often lead to what is known as “stick tights” where the husks remain intact while droughts are most frequently responsible for poor, shrivelled kernels. On commercial plantations it is common practice to irrigate the ground about one week before collecting the fruits as this encourages the nuts to fall clear from the husks. One Of Best The Japanese walnut, Juglans sieboldiana, is one of the best varieties of walnuts grown, being rapid of growth, and coming into cropping four to five years after being grown from seed. It is a very heavy yielder, very hardy and relatively disease resistant. It is also high in protein but low in oil.

The English or Persian most commonly offered by the trade which, although gener-

ally tolerant of a wide range of soil and climates, capable of withstanding extremes of hot and cold, is more suitable for lighter soils and can become sun scorched. The nuts are high in oil content. Juglans nigra, the black walnut, is often regarded as the national tree of the United States. It forms the largest of all the walnut trees, although both ultimate size and shape have proved variable, and the thick shell makes cracking difficult though flavour is good. The variety J. nigra “Thomas,” however, besides being a vigorous, rapid grower, produces a thin-shelled husk with a very good kernel. Earlier bearing can be expected where this walnut is grown on heavy soils. Another worthy American walnut is J. cinerea, whitenut or butternut, and the improved variety J. cinerea Denning, which is perhaps the hardiest of them all. Rich in flavour, the hard shell breaks easily and the kernel separates easily from the husk.