BULLETIN 231] WALNUT CULTURE IN CALIFORNIA. 213 



vigorous development in subsequent years. A nursery-grafted tree, if 

 planted at the same time, and especially under rather dry conditions, is 

 likely to fall behind the black walnut seedling and never catch up to it 

 again in growth. After three or four years the black walnut may be 

 cut off and grafted high, whereupon its large, vigorous root will furnish 

 the grafts with an abundant supply of moisture and force them into 

 rapid development. There is also some advantage in regard to sunburn 

 in the black walnut trunk, although we have seen such injury even to 

 the black walnut on rather dry soil. It is also true that sunburn is not 

 apt to prove serious with properly grown English walnut trunks on 

 good soil. 



The method of top-grafting black walnuts in place is open to one 

 objection in common with that of planting the nuts in place, namely, 

 that after grafting commences a uniform stand cannot be obtained the 

 first year, and the work will probably extend over at least three years 

 before all the trees bear a good top. In this way the orchard becomes 

 irregular and uneven. Again, it is objected with considerable reason, 

 that in this high grafting on trees several years old, very thrifty, 

 rapid-growing shoots develop from the grafts, which become extremely 

 top heavy, easily blown over by the wind, and a source of real difficulty 

 to keep up in shape until they are able to support themselves. On this 

 account there is now a tendency to graft low on such trees, within two 

 feet of the ground, even though most of the supposed advantage of the 

 black walnut trunk is thereby lost. 



Altogether, we may say that if the walnut orchard is to be planted 

 in good soil with irrigation, the disadvantages of this method over 

 planting nursery-grafted trees by far outweigh its advantages. At 

 best it is slow in producing a bearing orchard, it results in much irregu- 

 larity in the size and growth of the trees, the tops are very difficult 

 to support, and, under the conditions mentioned of good soil and mois- 

 ture, there is no real advantage in the end to offset these objections. 

 In planting a walnut grove to be grown without irrigation, especially 

 on rather shallow dry soil, where the trees at best may have a rather 

 scanty moisture supply, this method in spite of its disadvantages is 

 probably the best one to use. In following it extra good, one-year-old 

 seedlings of the best kinds should be obtained, these to be treated for 

 planting by digging with as much root as possible and cutting the 

 tops back severely, as described on page 248, planted out early in the 

 winter so that they will obtain all possible benefit of the winter rains, 

 and given all possible care during their first season's growth. A good- 

 sized circle should be kept cultivated or hoed about each tree, they 

 should be given a copious watering by hand as many times as possible 

 during the first season, and it is well to dig into the soil about them a 



