HINTS ON THE USE OF WATER. 37 



and manured for twenty years or more in a region averaging over 30 

 inches annual rainfall. And yet the popular notion is that a cactus 

 plant yearns for .a desert! 



HOW MUCH WATER AND HOW FREQUENTLY APPLIED? 



These questions, which are always being asked, can never be 

 answered. It is true that very interesting determinations have been 

 made of the amounts of water in the substance of different plants; 

 of the capacity of different soils to receive and to hold water; of the 

 amount lost by evaporation or drainage under different soil textures 

 and air-thirst but with all these factors variable it should be clear 

 that any general formula, workable everywhere would be so difficult 

 to understand and apply that no one could be sure of growing a 

 plant with it. There is however a better way and that is to learn 

 by patient observation how a plant looks when it has its best moisture 

 supply. Amount of growth; size, substance and aspect of leaves; size 

 and texture of flowers all these are among the tokens which a plant 

 given of satisfaction and the grower must learn to understand them 

 and use water to secure them, if he has made the soil right, as out- 

 lined in the preceding chapter. 



Water is the heaviest component of all growing parts of a plant 

 and water is therefore the chief plant food. Not only so but no other 

 nourishment can enter vegetable tissues through the roots unless it 

 be dissolved in water. Water to waste is also the plants protection. 

 Nothing but water can save the tender foliage from untimely blushing 

 beneath the too ardent gaze of the sun; nothing but libations of 

 water from the cells of the plant will save them from destruction by 

 thirsty air. Therefore, except in a water-less region, do not try to 

 determine how little water a plant can live upon; endeavor rather to 

 ascertain how much water it can use to advantage and supply it if 

 you wish to live in an amateur's paradise. 



As for the frequency of irrigation that also depends upon soil, 

 kind of plant and other variables but much also depends upon method 

 of application and that will be suggested in discussing the work for 

 the months of the year in Chapter XII. The aspect of the plant must 

 be the main guide in frequency as in amount of watering, and the wise 

 amateur will soon learn not to wait for signs of evident distress, but 

 always to prevent them. 



SOURCES OF IRRIGATION WATER. 



In other places* the writer has undertaken to describe with some 

 detail ways to get water by those whose premises are not reached by 

 public supply, delivered under pressure. This problem may be 



* "California Fruits," Chap. XV; "California Vegetables," Chap. V; Farmers' 

 Bulletins, (U. S. Dept. AgrJ, Nos. 116 and 138. 



