THE BLUE NYMPHiEAS 



87 



18 in. deep, the brickwork being 9 in. in thickness below the 

 ground level, whilst the upper part of it is 4^ in. thick. To this 

 is added, of course, the usual rendering in cement to ensure the 

 tanks being water-tight. Means in each case are provided for draining 

 the tanks dry for cleansing purposes. If I were again building tanks 

 for these Lilies I should only make one alteration, viz. I should 

 provide for a depth, at least, of 2 ft. of water, but preferably 2 ft. 6 in. 

 I recommend this because of the very vigorous growth of these Blue 

 Nyinphaeas and in order to better cover the crown of the plant to a 

 greater depth. We do not now take off the lights of the larger tanks 

 because we find that the Lilies become too much exposed to the force of 

 high winds, so much so in fact as to force the leaves out of the water on 

 to the pathway adjoining, otherwise we should continue to do so. The 

 smaller tank is now more frequently used for experimental purposes, or for 

 what are considered delicate or tender varieties. I surmise by the length 

 of the petiole, or leaf-stalk, of most of these Blue varieties that in their 

 native habitats the depth of water is much greater ; but I do not consider 

 it is necessary beyond what I have indicated. The greater the body of 

 water, the greater the pressure and the tendency to leakage in the tank. 



The Soil dtc. — Since we have grown these Lilies we have experimented 

 with various composts, but I have come to the conclusion that nothing 

 is so good and so safe for their well being as turfy loam, leaves of the 

 previous season, and road grit. We have tried manure, first that from 

 the cow-yard and then from the stables ; but neither is, in my opinion, 

 satisfactory or really essential. For the future I shall adhere to my first 

 season's choice, which was as above quoted and recommended. I like the 

 soil to be prepared and put into the tanks in a similar condition to that 

 in which we use our soils for fruit borders &c, i.e. in a good working 

 condition. By this means it can be made sufficiently firm without being 

 rendered adhesive. Upon the bottom of the tanks we place rough rubble 

 — broken brick-bats or clinkers to act as drainage. I would not in any 

 case place the soil directly upon the bottom, any more than I would pot 

 plants without any drainage, and for the same reason. This drainage is 

 about four inches in thickness, and upon it is placed a layer of rough 

 turf, then a layer of leaves (preferably those of the Oak or the Beech). 

 Upon this come the finer leaves and read grit into which the plants are 

 turned out from pots, and the water is immediately admitted, slowly at 

 first, in order not to chill the plants. Why we keep the leaves covered is 

 to prevent their floating, which for a time they would do, and that to the 

 detriment of the plants. (Of course under natural conditions the leaves 

 that settle upon the surface of the water and eventually afford a food for plant 

 life therein sink during the dormant season of the plants.) When the Lilies 

 are planted some clean gravel stones are placed around each one in order 

 to keep it firm and to prevent any tendency to float to such an extent as 

 to lift the tubers from their position. For a time after planting there is 

 nearly always a light scum that rises from the soil to the surface : this 

 vegetable growth, or " confervae," should be skimmed off every few days. 

 Presumably this is occasioned by the warming of the water whereby its 

 growth is festered. It is possible, I think, that this may arise from the 

 kind of water in use and not directly from the soil. 



