FERN GROWING 159 



necessity, and in such instances it should be given copiously, 

 as a mere sprinkling does no good, the benefit only lasting a 

 few hours. If it is merely a wet surface, evaporation soon 

 carries it away ; but if the ground is thoroughly wet to the 

 depth of four or five inches, the action below the surface is 

 slow. For bog Ferns, a low part of the Fernery well flooded 

 twice a day will be a good substitution for a marsh. After a 

 few dry days in summer the ground becomes parched, and it 

 requires water equal to that of a thunder-shower to do away 

 with this dryness. When it is requisite to resort to outdoor 

 watering, gardeners are apt to give too little. In 1893 the 

 drought dried the ground to the depth of nearly two feet. In 

 the midst of this drought there was a thunder-storm, which 

 threw down more than one hundred tons of water per acre ; 

 but this great amount only penetrated the ground to the depth of 

 one and a half inch, and four days afterwards the effect had gone. 

 The drainage-pipes that carry off the water into brooks had 

 no water in them till December 4, as it took all the autumnal 

 rain to moisten the ground. The rain from a thunder-storm 

 after the surface ground has become dry has great difficulty 

 in penetrating the ground, and a large amount of the water 

 runs on the surface to a lower level. 



Some Ferneries are planted without any regard to the 

 requirements of the different species. Osmunda regalis, 

 Nephrodium cristatum, and Nephrodium thelypteris are bog 

 plants, and delight to be in a situation where their roots can 

 descend to the water. They can all be successfully grown by 

 copying nature, either by making a bog with water and clay, 

 and then growing the plants in pots placed on small mounds ; 

 or by burying a large pan in the ground that will hold water 

 below the roots. 



The Asplenium Trichomanes, A. viride, A. ruta-muraria, 

 and A. Ceterach, if grown out of doors, require a rockery 

 built against a wall, looking towards the north, and raised 



