Sub-Irrigation 



short distance beneath the surface a continuous supply of moisture exists ; 

 the result being that in Holland many classes of bulbs, shrubs and trees 

 are grown better and cheaper than in almost any other portion of the globe. 



Sub-irrigation has been applied to the growing of carnations to a con- 

 siderable extent, and has been practiced by the author at Queens for the 

 past seven years. The results of the experiments carried on during that 

 period have been rather in favor of the sub-irrigation bench as compared 

 with surface-watered benches. The chief objection which has been found 

 to the former benches has been their first cost, as they are rather too expen- 

 sive for general use by florists with limited capital. This, to some extent, 

 is largely overcome by the permanency of the structures once they are 

 installed, as a sub-irrigation bench, properly built, will last as long as ten 

 ordinary wooden benches, and in the end cost considerably less. The other 

 objection is that while better results can be secured if sub-watered benches 

 are properly handled by skillful growers who have had experience with 

 them, the work requires more judgment and a higher degree of skill. This is 

 largely offset by the fact that, with plants growing upon sub-irrigation 

 benches, a grower can care for the watering of two or three times the area of 

 bench surface that he can handle on the surface-watered bench, as much less 

 labor is needed in watering; and growers who have once mastered the man- 

 agement of such benches prefer them to the surface-watered ones. It may be 

 said, however, that in the hands of a careless grower the sub-irrigation bench 

 is more dangerous than those surface-watered, for the reason that when once 

 the bench is over-watered it takes a long time to dry out properly ; whereas 

 with the surface-watered bench, even if it is over-watered, the drainage 

 from the bottom and the evaporation from the top, and the stronger degree 

 of heat to which the bottom of the bench is subjected, cause the water to 

 evaporate much faster and the soil to dry out in much less time than is 

 the case with an over-watered sub-irrigation bench. 



The soil in sub-irrigation benches is generally in a better mechanical 

 condition than in a surface-watered bench, providing the watering has been 

 done with proper skill and judgment. As before said, the danger with the 

 sub-irrigation bench lies in over-saturing the soil with water, thereby 

 destroying the young feeding roots. However, if the sub-irrigation bench 

 is treated properly, the plants will not only make a generally better growth 

 than upon the surface-watered bench, but the stems will be longer, the 

 flowers larger and of better substance, and the crop will be increased a 

 notable percentage. Where sub-irrigation benches are operated as they 

 should be, the lower portion of the soil becomes filled with roots, and these 



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