WATERING FORCING-HOUSES. 67 



is applied, and the normal condition of the surface should 

 be simply moistness, not wetness. Of the two extremes, 

 an habitually dry surface soil is much better than an 

 habitually wet one. The fungi of damping-off breed pro- 

 fusely upon wet surfaces ; and these soils are the ones, too, 

 upon which the green "moss" (which is really an alga) 

 thrives. All this means that when water is used on the 

 soil, it should be applied thoroughly, and that the un- 

 der soil should remain moister than the surface soil. 

 Frequent and slight waterings produce just the opposite 

 conditions of distribution of moisture, and thereby invite 

 fungous disorders at the same time that they withhold 

 water from the roots of the plants. 



Benches usually require closer attention than beds do, 

 especially (as in the case of tomatoes and melons) when 

 they are subjected to strong bottom heat. The earth 

 then dries out both on top and bottom. It is the com- 

 monest thing to find the soil in such benches as dry as pow- 

 der at the bottom whilst it is abundantly moist on top ; 

 and the gardener is generally found to be wondering why 

 his plants ripen up prematurely and bear no crops of con- 

 sequence. The thorough watering which has been ad- 

 vised above applying the water until the moisture can be 

 seen or felt along some of the cracks on the bottom of 

 the bench will remedy this common difficulty ; but the 

 operator must be warned that if he allows any water to 

 drip through his bench he may be leaching away valuable 

 plant food. Beds upon the ground dry out from only one 

 surface, and they usually replenish their store of water from 

 the earth by means of capillary action. It is, therefore, 

 necessary to exercise care not to water such beds too 

 heavily. With profuse watering, they soon become 

 soggy, cold and "sour." In the fall and spring months, 

 it is generally necessary to water forcing-house soils every 

 day, but in winter the operation may not be necessary 

 oftener than once or twice a week. There is particular 

 danger of keeping the soil too wet and cold in the long, 



6 FORC. 



