134 AGRONOMY 



When not in use it should be kept with the seeds where it 

 will be ready when more planting is to be done. Seeds must 

 not be planted too deep. In general they should be planted 

 three or four times as deep as their diameters. Seeds whose 

 cotyledons do not rise above the soil may be planted deeper 

 than those whose cotyledons do, and large seeds may be planted 

 deeper than smaller ones. Very small seeds may be simply 

 scattered on the surface and pressed into the soil with a hoe 

 or a piece of board. When sown in light, well-drained soil, 

 the seeds may have the earth firmed over them to induce 

 capillarity, but in wet or heavy soils this should be omitted, 

 else it may be so compacted that delicate plants cannot push 

 through it and the air necessary for germination be excluded. 

 Darkness favors the germination of most seeds, and for this 

 reason, as well as to prevent the drying out or puddling of 

 the surface layer of soil, it is well to mulch newly planted 

 seeds with a light covering of loose straw or lawn clippings 

 through which the young plants easily push their way. Cover- 

 ing the planted seeds with paper or cloth serves the same pur- 

 pose, but in such cases the cover should be removed as soon 

 as the young plants appear. 



When to plant. The seeds of the hardier plants may be 

 sown as soon as the ground can be worked in spring, or they 

 may even be sown in the autumn and allowed to rest in the 

 soil through the winter. This is the way all the wild species 

 are planted. Other seeds must not be planted until the soil is 

 thoroughly warmed. Several garden plants thrive only in the 

 cool moist days of early spring, and do not grow well if 

 planted later. This is especially true of spinach, cress, radishes, 

 lettuce, and the like. In hot dry weather these plants soon 

 " run to seed." Among the vegetables that are usually planted 

 early are beets, cabbage, cress, lettuce, onions, peas, radishes, 

 salsify, and spinach. These are either cool-season or long-sea- 

 son plants that are not injured by light frosts. Warm-season 



