FLORICULTURE 511 



application of the knowledge gained. The men to-day most familiar 

 in a practical way with the requirements of different plants, so far 

 as soils are concerned, are those actually engaged in agricultural and 

 horticultural pursuits. By the appearance of the soil to the eye and 

 by the way it feels when taken in the hand, a gardener can tell 

 pretty accurately whether a certain soil will be suitable for a certain 

 kind of crop. This knowledge is largely intuitive, and has been 

 gained by long experience and close observation. 



Speaking generally, it may be said that the perfect development 

 of any plant, so far as the soil is concerned, depends upon two 

 fundamental considerations: (1) The presence of the necessary 

 amount of suitable food, and (2) the physical properties of the 

 soil that is, its texture and its relation to heat, air, and water. 



That growth is dependent on the presence of proper food in 

 the soil is now well understood, but how to supply this food so as to 

 obtain the largest yields at the least expense is a problem of the 

 utmost importance to everyone growing plants under glass for com- 

 mercial purposes. As the work is now carried on, there are but few 

 crops where it is practicable or desirable to add sufficient food at 

 the start to carry the plant through the full season of growth. Feed- 

 ing must be done through the entire growing period, and to do this 

 properly is one of the most important problems with which the com- 

 mercial grower has to deal. 



The relation of the physical properties of the soil texture, 

 temperature, and moisture: to plant growth is not so well under- 

 stood nor appreciated. It is obvious that these are not intimately 

 connected with the chemical properties (food supply) ; in fact, it 

 is a matter of common observation that the mere presence of an 

 abundant supply of food is not sufficient to make a good crop, even 

 though other conditions outside of the soil are to all intents and pur- 

 poses perfect. This is well illustrated in the growing of roses, car- 

 nations, and other flowers. Certain varieties of roses and carnations 

 may be grown to a high state of perfection in some sections, using, 

 of course, proper judgment and skill in the management of the con- 

 ditions. In other sections, and they need not be remote, it is diffi- 

 cult to get a perfect crop, although the skill of the grower may be 

 fully as great as in the former case, and the use of manure as food 

 may have been fully as judiciously made. In such cases the texture 

 and structure of the soil, which involve also the capacity of the 

 latter for heat, moisture, air, etc., may be the basis of the trouble, 

 and all these have a direct influence on food supply. 



By texture is meant the character of the particles which make 

 up a soil, while structure has to do with the arrangement of these 

 particles and their relation to each other. The particles, or grains, 

 of which soils are composed vary greatly in size, and to distinguish 

 them they have received certain conventional names, such as clay, 

 fine silt, silt, fine sand, sand, etc. The clay particles are extremely 

 minute, silt grains are larger, and so on until we have coarse sand 

 or gravel, with grains 2 mm. in diameter. 



