A ND EXPERIMENT STA TION. ] 37 



intervals in the plantation, so that no appreciable opening for 

 weed growth is left, as would happen if a group of them were 

 made. It is important to keep the value of dense leafage con- 

 stantly in mind in planting a mixed grove. 



SMALLER TRKES. In natural forests we find as great varie- 

 ty in sky line as in grouping, caused by mixture of tall growing 

 and low tree forms. Usually the openings among the high trees 

 are occupied by shrubs, like wild gooseberry, dwarf Juneberry, 

 currant, sand cherry, or the larger choke cherry; and in more 

 open woods, and in the borders of groves, by the wild plum, haw- 

 thorn, and similar low growing forms. And so in our artificial 

 groves all these things may have a place. Their value as tim- 

 ber is of course nothing, but the birds love them, and they make 

 a more complete soil cover. The fruit of the wild plum is valu- 

 able, and by top grafting seedlings of the wild stock, any one 

 can have in the borders or openings of his grove, plums of the 

 best quality. The other plants mentioned furnish fruit for birds, 

 and these friends should not be forgotten, for they are the best in- 

 sect exterminators that can be brought to the farm, In addition 

 to these arguments in favor of including small trees and shrubs 

 in the forest plantation, is the constant one of additional beauty 

 and variety to the grove, and consequently greater attractiveness 

 for the prairie home. Many open groves can be gradually im- 

 proved by the introduction of low woody plants, which succeed 

 in the shade of other trees, where timber forms would fail. 



STREET TREES. 



The varieties that seem best adapted to street planting are 

 white elm and box elder, the elm being the finest street tree that 

 is native to the temperate zone. Cottonwood grows better in sin- 

 gle rows than in close plantations. To many it is an attractive 

 form, and where the cottonwood leaf beetle has not appeared it 

 makes a fair street tree, though never giving the dense shade of 

 box elder. Silver maple ranks next to white elm and box elder 

 as a street tree, and will be found satisfactory in the southern 

 half of the state. It is apt to throw out strong "water sprouts" 

 near the crown, which are sometimes difficult to get rid of. In 



