The belief has been quite general in this country that budding or grafting the nut trees has proven more uncertain and difficult than the grafting of the stone fruits. But where thrifty young stocks are used in European nurseries a better stand of nut trees is usually secured by grafting than with the plums and cherries.
The most perfect success known to the writer has been reached by using young thrifty stocks and inserting the grafts under the bark (94. Bark-grafting) as soon as the bark can be raised, when the buds are well started. The scions used are also started and are cut as used. The wounds are waxed, as is also the end of the scion. A paper sack is then tied tightly over the stock and scion to lessen evaporation. If left without tying, the paper sack in high winds is apt to break or loosen the scion. This is the favorite method of grafting the oaks and all tree-growing species of the nut family in west and east Europe. The plan known as ring or flute budding (77. Ring-budding) has also given good results in west Europe and in California.
On thrifty young stocks California propagators have had success also with the walnut by summer budding (72), using the smaller buds at the base of the young wood scions. But in Europe and on the west coast the stocks in which the summer buds are inserted are not cut back until the next spring, and then are cut with a high stub, to which the growing shoot is attached by tying.
The varieties of English walnut so far cultivated in this country have come to us from the equable and rather moist climate of west Europe. At Ames, Iowa, they have proven far more tender than peach-trees. But a variety grown from nuts gathered at Saratov in south Russia has proven far hardier than the peach and perfectly hardy in Missouri. As noted on former pages of the orchard fruits, we now have access commercially to central Asia. In this dry interior climate, walnuts with thin shells are grown extensively, and beyond doubt they will prove worthy of trial in our interior States.