AND EXPERIMENT STATION. Ii27 



mixed. A mixed plantation presents an uneven sky line to the 

 winds and forms a better barrier against them. More trees can 

 be brought to maturity in mixed than in homogeneous planting, 

 as the intervals between the taller growing sorts are well adapt- 

 ed to certain shade enduring kinds. In many cases, too, the 

 varieties that are of rapid growth in youth are overtaken and 

 passed by others which are of very slow growth, and which need 

 protection, while young. This is true of such sorts as box elder 

 with the walnuts and oaks. The very .rreat majority of trees 

 used in a plantation should be of a qirck growing kind with 

 dense foliage, so that the ground may bu shaded as soon as pos- 

 sible, and weed growth thus prevented. Among these, at inter- 

 vals from twelve to sixty feet, slower growing sorts of greater 

 economic value can be placed. By this arrangement cultivation 

 is only necessary four or five years, and the "nurse" trees (the 

 rapid growing kinds) will have compelled the slower growers of 

 greater value to reach upward for light, and thus grow a straight 

 trunk. The rapid growing kinds are then removed as needed. 

 In all prairie planting, the greater part of the forest should be 

 composed of trees with good foliage, rather than of such varie- 

 ties as cottonwood, which do not make a dense shade no matter 

 how closely they are planted. 



By close mixed planting height growth is first secured. As 

 the trees are thinned, however, especially if the final removal ot 

 nurse trees be deferred until the height growth is almost attained, 

 the diameter of the boles increases rapidly, and usable timber is 

 secured more quickly than by more open planting/ 



Another advantage of mixed planting, and one that is of the 

 first importance, is the relative freedom from insect ravages in 

 mixed plantations. If the mixture includes some fruit bearing 

 trees, like the wild cherries and plums, birds will be attracted by 

 them, and these friends will prove the most valuable insect 

 destroyers about the farm. Usually an insects attacks but one 

 or two species, and so in a mixed grove there would always be 

 many trees that would escape. 



It is not necessary or desirable in mixed plantations, that 

 there be same number of trees of each species. One species, 

 such as box elder, or in parts of the State where it is available 



