HORTICULTURE 253 



a more extensive structure, if he gives close attention to 

 airing, watering, and keeping out insects. 



Sowing. The time for sowing the different kinds of 

 seeds is an important matter. Seeds vary greatly in their 

 requirements. All need three conditions, a proper degree 

 of heat, moisture, and air. Some seeds, like English peas, 

 parsnips, beets, and radishes, will germinate and grow when 



FIG. 221. GREENHOUSE AND COLD FRAMES 

 Permission of the Lord & Burnham Company, New York 



the soil is still cool in the early spring, and peas will 

 stand quite a frost after they are up. Therefore we plant 

 English peas as early as the ground can be worked. 



But if we should plant seeds like corn, string or snap 

 beans, squashes, and other tender plants before the ground 

 is warm enough, they would decay. 



Seeds cannot germinate in soil that is perfectly dry, 

 for there must be moisture to swell them and to start 



