Some of our cultivated trees and plants, that under natural conditions drop their seeds in forest shade, seem to require the same protection when propagated in open exposure. This is specially true in interior climates, such as the prairie States, with such trees as the conifers and the birches. For shading the beds, lath frames for the top and sides are now generally used. Amateurs and smaller growers use beds four feet wide covered with lath frames four feet square, only eighteen inches above the bed, with sides lathed to exclude the birds. Larger growers erect a framework high enough to work under, covering the top and sides with lath, with three-quarter-inch spaces between them.
Fig. 2 shows the plan of making the lath screen, and Fig. 3 gives the plan of lath-covered shed for sheltering seed-beds from the direct rays of the sun and to lessen evaporation. These are made large enough for a number of beds, highest in the centre, to run off surplus water from rains into the slightly sunken paths between the beds. The seed is sown in drills very shallow, and the surface is covered at once with evergreen leaves or othei light shading to lessen evaporation, which is mainly removed when the plants begin to appear. The after-care of the seedlings is given in the chapter on seedling-growth.
Fig. 2. - Lath Screen.