THE f^ 



GARDEN YARD °" 



the plant. The "best temperature" varies 

 with the species and variety. Usually, if the 

 soil is hotter than that, growth stops, and if the 

 greater heat is kept up, the plant dies. When 

 the temperature is lowered, growth ceases before 

 freezing point is reached. Some few plants may 

 be frozen without injury if they are allowed to 

 thaw slowly, but most of them are easily killed 

 by the frost. Too great heat or too much cold 

 acts the same as lack of water; the heat causes 

 too great evaporation, the cold prevents the 

 roots taking in the water. 



Shingles stuck in the ground on the sunny 

 side will serve to protect young plants from sun 

 and rain, while cool soil may be had by using the 

 shady places, or by sheltering the ground with 

 flat sheds the roof boards of which have open 

 spaces between them as wide as the boards. 

 This is done in some southern tobacco fields. 



It is the law of nature that living cells must 

 have a constant supply of oxygen, that is why 

 a tar wash sometimes kills plants by cutting 

 off the air supply. In the same way, too wet 

 soil or too hard a crust smothers the roots and 

 the plants die. The surface soil should be kept 

 loose and sufficiently dry, so that the air can 

 circulate. If this be prevented, the soil be- 

 comes hard and sour and unfit to feed plants. 



