76 NUT GROWING 



most promising stock. This has not as yet been 

 worked out excepting for nursery trees in very re- 

 cent years. There will be many advantages in find- 

 ing a range of stocks upon which any one species 

 may be best grown. For instance, the shagbark 

 grafted upon the bitternut may bear in low or very 

 swampy ground, where most of the hickories will 

 not grow, and if the same shagbark will grow upon 

 the stock of the mockernut in poor dry soils, shag- 

 bark hickories may then be raised in thin sandy soils 

 in which the mockernut is often very thrifty. 



The Persian walnut apparently takes very kindly 

 to the black walnut as a stock tree. This gives the 

 Persian walnut a wider range than it would other- 

 wise have because the Persian walnut prefers a soil 

 that is neutral or alkaline and is rather intolerant 

 of soils with acid reaction. The black walnut, on 

 the other hand, will not simply grow in acid soils 

 but will sometimes thrive in soils of such reaction, 

 thus increasing the range of the Persian walnut. 

 Furthermore, the Persian walnut root is a favorite 

 with the field mice which burrow about the roots, 

 sometimes injuring the roots very seriously. Field 

 mice seem to care very little for the root of the 

 black walnut and this gives an added advantage. 

 I did not realize the extent to which field mice fed 

 upon the root bark of walnuts and on some of the 

 hickories until I had occasion to dig down to the 

 roots for experimental root grafting. The roots of 

 the Persian walnut, bitternut, and butternut were 

 sometimes found to have been stripped of bark for 



