66 MANAGEMENT OF THE FORCING-HOUSE. 



to carry the plants too cool through the night, for the body 

 of warm earth is a powerful factor in regulating and con- 

 serving the night temperature of the house. While it is 

 generally not advisable to thoroughly water the soil from 

 a hose in the middle of the day, it is, nevertheless, very 

 essential that the most profuse waterings be given on 

 sunny days. This is because, as already stated, the sun 

 soon warms up the house, and also because the house and 

 foliage soon dry off. Houses which have a continually 

 damp air breed soft plants and fungous diseases. The 

 plants should go into the night dry never wet. It is 

 always best to withhold water on dull days, unless the 

 plants are actually suffering for it. Perhaps these remarks 

 cannot be better summed up than by saying that glass 

 houses should be watered on a rising temperature, not 

 on a falling temperature. 



The next most important secondary effect of watering, 

 as already indicated; is the modification of the physical 

 texture of the soil. The application of water tends to run 

 the soil particles together, thus solidifying or compacting 

 the earth. In the instance of clay soils, this cementing 

 action of the water may proceed so far that the surface of 

 the bed may become actually hard and almost non-absor- 

 bent of water. When soils arrive at this condition, they 

 are incapable of producing good plants, no matter how 

 much plant food they may contain. There is greater dan- 

 ger of compacting the soil when watering from a hose 

 than from a pot. A good forcing-house soil remains open 

 and porous to the last. The water quickly settles away 

 into it and leaves the surface friable and open. When 

 the surface remains wet and sticky, good plants are grown 

 only with much difficulty. The physical condition of the 

 surface soil may also be greatly improved by fre- 

 quent tillage, for stirring the soil (an inch or so deep) as 

 often as it becomes hard is quite as necessary in the 

 forcing-house as out of doors. 



The entire body of soil should be wetted when water 



