234 TREES AND TREE-PLANTING. 
set between them. Eighteen inches wide would be suf- 
ficient for the willows, with spaces of three feet three 
inches on either side between them and the permanent 
trees. This plan would be particularly applicable to 
plantations of some of our oaks and hickories, which are 
usually slow in their growth. 
“Tt is recommended in planting the black walnut, that 
instead of an entire block of this species, which is uncer- 
tain in its results, every fifth row be planted with nuts, 
while the four intervening rows on either side be set 
with any of the common kinds as nurses, and as their 
growth increases, and consequently space is needed for the 
thrift of the walnut, the adjoining rows of nurse-trees 
may be cut down, and so the next, till a clear space of 
sixteen feet is made to allow of the development of the 
permanent tree. This manner of proceeding, though 
remunerative in the case of the black walnut, has proved 
to be with other species a false economy on the part of 
the planter, under the delusive idea that he could grow 
among the trees a half crop of other plants to pay him 
for the labor of cultivating his trees. For the first year 
he may reap his reward; in some cases, perhaps, also for 
the second year, but, meanwhile, when so widely planted, 
the trees suffer from branching and by leaning out on 
either hand for the light and air. It is true that in some 
cases, with very strong and rapid-growing species, tall- 
growing kinds of Indian corn in the alternate rows might 
supply the need of the supernumerary trees. 
“The white willow has been used as a nurse to the 
sugar maple and oaks with the object of saving the 
more valuable stock-plants, by filing up with willow- 
cuttings to shade the ground, thus diminishing the ex- 
pense of planting and cultivation, and at the same time 
to force the upward growth of the trees and to prevent 
their branching. 
“Tn planting the oaks at eight feet apart each way, 
with alternating willow-cuttings in the rows, and with 
