MARCH: SECOND WEEK 63 



hardening of the stem and roots, which may result from 

 checking the growth by giving too little water, too low 

 temperature or too Httle room. This puts the plants in a 

 semidormant condition from which it takes them some 

 time to recover, even after they are placed in a more favor- 

 able environment. The growing parts of the plant, both 

 above and below ground, should be firm, but juicy and 

 rather brittle. When they become tough and wiry the 

 development of new plant tissue is checked. 



Factors That Affect Growth 



Various factors influencing the growth of plants — food, 

 water, air, Kght, heat and protection from insects and dis- 

 ease — are all, in the case of plants being started early in the 

 greenhouse or hot-bed, pretty much under the grower's 

 control. This is at the same time an advantage and a dis- 

 advantage, for while he is independent of the vagaries of 

 temperature and insufficient rainfall, Nature cannot help 

 him if he forgets to attend to anything himself. Anyone 

 who expects to grow plants of prime quality should make 

 himself familiar with each of these things that affect growth: 



Food. For plants started early, when rapid but sturdy 

 development is wanted, food should be given in highly 

 available forms but in a- balanced ration. Too much nitro- 

 gen is likely to result in oversucculent or flabby growth. 

 Soil for transplanting or potting up should be much richer 

 than that for seedling plants. Nothing is better than the old 

 stand-by, well-rotted manure, but it should be particularly 

 well rotted and also finely pulverized. 



If fine enough and dry enough the manure may be mixed 

 with the soil, but often it is more convenient to put a layer 

 of manure in the bottom of the flat or pot and cover this 

 with the soil in which the plant is to be set. If the manure 

 to be used in the bottom of flats is left in a lumpy condition 

 the plants may grow as well, but in taking them out the 

 roots will be damaged much more than if the manure had 

 been run through a sieve. When stable manure caimot be 



