THE SEED 43 



of the seed and the nature of the soil. It is apparent, however, 

 that the small, delicate seed, whose powers of germination 

 are reduced in proportion to their size, should have very 

 little covering, because the tender plantlet will be unable 

 to push through the soil. In the large and vigorous seeds 

 this precaution need not be taken. However, it is never 

 beneficial to cover the seed deeper than is really necessary 

 to secure the requisite degree of moisture. Many small 

 seed are often sown upon the surface of the soil and covered 

 with a thin mulch, while some others need no covering, except 

 a pane of glass to retain the proper amount of moisture. If 

 the seed are planted in the open, the same precautions are 

 necessary. 



Fig. 10. — A firming board. 



.Compacting of the Soil. — ^The seed must be in intimate 

 contact with the soU particles in order to secure the proper 

 amount of moisture to germinate. If the soil is loose about 

 the seed they get but little moisture, which prevents their 

 maximum germination and the subsequent growth of the 

 plantlet. In nearly all cases the soil must be firmed over the 

 seed to give the best results. This is accomplished in many 

 field crops by the use of heavy rollers. In market gardening 

 the roller follows the seed drill and is usually a part of it. 

 When seed is sown in flats a firming board is usually employed 

 to compact the soil about the seed, or the soil may be pressed 

 down with the hands. 



Time to Plant. — ^All plants require a definite period in order 

 to grow to maturity. The proper time then to sow the seed 

 would be such that the growing period would be long enough to 

 bring the crop to its full state of ripeness. The time at which 

 planting is to be done must be kept in mind, remembering, 

 however, that seed of certain plants that are sown too early 

 or too late, and which will encounter unfavorable heat or 



