288 SEEDING AND PLANTING 



the beds are sown in early spring while the soil is cold. This 

 method of protecting autumn-sown seedbeds is not as satisfactory 

 as the ordinary mulch, particularly if the soil is heavy and liable 

 to crack. 



The relative advantages of scrim, cheese-cloth, and burlap de- 

 pend chiefly upon the cost of the material and the degree of pro- 

 tection required. Cheese-cloth affords the least protection and 

 burlap the most. Scrim is intermediate in its effect. Where one 

 of these materials is used it is spread over the seedbed in contact 

 with the soil and tacked to the curb or held in place by pegs 

 driven into the ground at either side, or it is attached to frames 

 which raise it a few inches above the surface of the bed. When 

 scrim is used only during the period of germination, it is spread 

 over the beds in contact with the soil. When also used to shade 

 the beds after the seed germinates, it is tacked to frames. As 

 soon as germination begins the frames are raised a foot or more 

 above the beds and are held in place by stakes driven into the 

 soil along either side. 



25. COVERING WITH LATH SCREENS OR WITH SEEDBED BOXES. 

 The following is a simple, efficient, and inexpensive method 

 for protecting seedbeds prior to germination in nurseries where 

 screens made of laths are later used to protect the young seedlings 

 from the wind and sun. The beds are surrounded by board 

 strips 4 inches wide and 1 inch thick. These strips are set on edge 

 along the margin of the beds or on the curbs when present. The 

 ordinary lath screens 4 by 6 feet or 4 by 12 feet are placed on these 

 strips which raise them a few inches above the beds. The spaces 

 in the screens are filled with loose laths. This serves to enclose 

 the beds completely, and prevents the free movement of air and 

 the loss of moisture from the surface soil. 



In nurseries where the ordinary seedbed boxes are used they 

 are adjusted over the beds prior to seeding and serve to protect the 

 seed during germination as well as the seedlings after germination 

 takes place. These boxes are usually made as follows: 1 A frame- 

 work of wood, usually 12 feet long, 4 feet wide and 1 foot high, 

 covered on the sides and ends with f-inch mesh netting, is first 

 placed in position over the bed and sunk in the soil so that the top 

 of the bottom sill, which serves as a curb, is level with the soil at 



1 Pettis, C. R.: How to grow and plant conifers in the northeastern states. 

 (U. S. Forest Service, Bui. 76, p. 16. 1909.) 



