292 SEEDING AND PLANTING 



Mississippi River, experience has not as yet demonstrated the 

 wisdom of growing coniferous stock without cover. The covering 

 of the beds during germination and partial shading during the first 

 season should not be dispensed with in any locality in the United 

 States until experience has demonstrated that the elimination of cover 

 and shade is an economic advantage. 



A more or less firm crust sometimes forms on the surface of the 

 soil which prevents small-seeded species from breaking through as 

 they germinate. Large flakes of crust are sometimes raised up 

 an inch or more by the thousands of rapidly germinating seeds 

 beneath. This condition is extremely disastrous to what would 

 otherwise be excellent germination. It can be prevented by breaking 

 the crust prior to germination with the special tool described below. 

 A flat board 18 inches long and 12 inches wide is filled with nails 

 set in rows 1^ inches apart and spaced inch in the rows so that 



FIG. 68. Tool for breaking the surface crust of seedbeds prior 

 to germination. 



the nails in one row alternate with those in the next. The points 

 extend \ inch below the lower face of the board. A straight handle 

 about 4 feet long is attached in such a manner that the board can 

 be quickly passed over the bed driving the small teeth into the 

 crust and effectively breaking it without disturbing the position of 

 the seed (Fig. 68). 



27. SHADING SEEDLINGS WITH NATURAL COVERS. Seedbeds 

 may be shaded with either natural or artificial covers. The most 

 common form of natural cover is an open stand of wide-crowned 

 trees that give from one-half to one-third shade. Although alder 

 is often grown under this form of cover in Prussia and a great 



