298 SEEDING AND PLANTING 



used in many forest nurseries (Fig. 67). The shade screen is the 

 uppermost cover of the box. It is made of laths nailed to a frame 

 12 feet long and 4 feet wide, which fits the top of the box and 

 can be removed and replaced without disturbing the wire screen 

 beneath. 



33. Scrim, Cheese-cloth, or Burlap Screens. Screens made by 

 tacking scrim, cheese-cloth, or burlap over wooden frames serve 

 very well for protecting seedbeds from the sun. The frames are 

 usually 4 by 6 feet in size and are made by nailing together two 

 side pieces 6 feet long and 4 inches wide, and two end pieces 4 

 feet long, in the form of a rectangular frame. The side pieces are 

 set on edge and the end pieces are set flatwise. The fabric is 

 stretched over the frame. When the frame rests on the seedbed 

 the side pieces raise the fabric slightly above the surface of the 

 bed. 



The screens are quickly made, are relatively inexpensive, and, 

 when properly cared for, last from two to four years. They serve 

 a double purpose. By placing them over the seedbeds immediately 

 after seeding they protect the beds prior to germination. When 

 germination begins they are raised a foot or more above the beds 

 and supported on stakes. This method of shading seedlings is 

 seldom used in forest nurseries in the United States. In New 

 Zealand coniferous nursery stock of many species indigenous to 

 the United States is grown under similar screens. 1 



Except in dry, warm regions where there is a maximum of sun- 

 light the broken shade produced by lath screens or brush is prefer- 

 able because the danger from overshading is not so great. 



Beech and some other tolerant broadleaved species cannot be 

 grown in most localities without protection from the sun during 

 their early development. This can be attained by erecting a brush 

 or lath cover over the seedbeds or, according to Bagneris, 2 by the 

 following method of culture. The seed is sown at the bottom of 

 narrow trenches running east and west. These trenches are 4 

 inches in depth and, as the plants develop, the soil is filled in about 

 them until level. The base of the young stem is particularly 

 sensitive to direct exposure to the sun. Injury is prevented by 

 this manner of protection. 



1 Goudie, H. A.: State afforestation in New Zealand. (Report, Dept. of 

 Lands, p. 7. Wellington, 1911.) 



2 Bagneris, G.: Manuel de sylviculture. 2. <d., p. 259. Paris, 1878. 



