AQUATICS 



nine of soil is sufHcient. Chemical manures, ground 

 bone, horn shavings, etc., should not be used unless in 

 extreme cases, and then very cautiously. 



Depth or Wajer.— In natural ponds, water-lilies are 

 found growing in water from a few inches to i and 6 

 feet deep, but in artificial ponds a depth of 32 to 18 inches 

 will be found sufficient for most Nymphseas, and 18 to 24 

 inches is a good depth for Victorias. In constructing an 

 artificial pond, a depth of 2 to 2% feet is ample. Water 

 to the depth of 12 inches above the crowns of the plants 

 is sufficient, and a box containing the soil may be 12 inches 

 deep. Thus a pond 2 feet in depth is deep enough, and 

 will allow a man, with hip boots on, to walk between the 

 plants with ease. For a small pond, less than 12 feet 

 over, a plank laid across will suffice for all operations. 



Protection.— Where severe frosts are prevalent in 

 winter, and ice 12 to 18 inches in thickness is found, 

 there will be danger of the roots freezing. In such cases, 

 an additional depth of 6 inches will be a great advantage, 

 and a protection of bracken, salt hay, green manure, 

 leaves, or any other non-conducting materials should be 

 "used to protect the masonry, in severe weather, against 

 expansion and breakage. 



Planting. — All hardy Nymphseas may be planted any 

 time between the 1st of April and the l.it of September. 

 Those planted early, other things being equal, will give 

 good results the same season, while those planted late 

 will get well established before winter, and will be in 

 excellent condition to start at nature's summons early 

 the following spring. The hardy N>Tnph£Bas differ con- 

 siderably as to rootstocks. Those of the native varieties 

 are long and of a spongy, soft texture, and rambling in 

 gro^vth, while the European species have a much larger 

 and very firm rootstock, and grow more compact. In 

 planting, all that is necessary is to press the rootstock 

 firmly into the soil, and if there is any danger of the 

 root rising to the surface, place a brick or any weight 

 upon it, to keep it in position until anchored by its own 

 roots. Tender Nymphaeas should not be planted until 

 the latter end of May or beginning of June, according to 

 location. They should not be planted out before Coleus, 

 Alternanthera, and other tender bedding plants. They 

 require to be started indoors, and will be grown in 

 pots, which are much handier to plant than roots of the 

 hardy varieties, and can be planted under the water with 

 ease and facility. Nelumbiums should not be planted 

 until about the 1st of May. Southward the season is 

 earlier. The existing conditions should be such that 

 tubers shall start at once into active growth. They should 

 be already " started " before setting out. The tubers 

 should be laid horizontally in a slightly excavated trench 

 and covered with 2 or 3 inches of soil, using a weight, 

 if necessary, to keep the tubers in position. Plants, 

 established in pots or pans, are very convenient for 

 planting, and may be purchased when tubers can no 

 longer be procured, and can be planted a month later in 

 the season with good results. 



The Victoria jRegia has always been an aristocrat 

 among water-lilies, and few cultivators could indulge in 

 such a horticultural luxury. To grow it satisfactorily, 

 a large surface space with a greater depth of water is 

 necessary than for other aquatics, and a higher tempera- 

 ture is needed at the early stages. It can be cultivated in 

 the open air, but artificial heat must usually be applied 

 and protection afforded, so as to maintain a temperature 

 of 85° P. This applies more particularly to the varieties 

 y, Uegia and V. JSandi. In 1898 the introducer of V. 



AQUATICS 



83 



Trickeri brought the Victoria within easy reach and cul- 

 ture of all lovers of aquatic plants. V. Trickeri is en- 

 tirely distinct from other known varieties, and can be 

 grown in the open alongside of Nymphcea Zanzibarensis 

 and iV. Devo>iiensis, and under precisely the same con- 





123. Tub of water-lilies. 



122. Lawn pond of aauatics, with mason-work margin. 



ditions. When planted out about the middle of June, 

 the plants grow rapidly, and will develop their gigantic 

 leafage and magnificent flowers in August, and continne 

 to do so until destroyed by frost. 



Enemies.— Aquatics, like other plants, have their ene- 

 mies in the line of insect pests, though in a less degree 

 than most plants. Aphides are sometimes troublesome, 

 or at least very unsightly. These, however, have their 

 enemies, especially the coccinella (lady-bird), insectiv- 

 orous birds, etc. Where these do not keep them down, 

 a weak application of kerosene emulsion will make a 

 clearance. Another method of getting rid of these pests, 

 especially in a small artificial pond, where an overflow is 

 (or should be) provided, is to take the hose with a spray, 

 using a little force, and drive the insects off the plants, 

 and, as they readily float on the water, the action with 

 the hose will drive them out at the overflow pipe. Re- 

 cently an insect pest that has its home in Florida has 

 migrated northward, causing some annoyance. The larva 

 of the moth {Hydrocampa proprialis) eats the leaf, and 

 also cuts out pieces of the same, which it uses for protec- 

 tion, thereby greatly disfiguring the plant, and at the 

 same time making it difficult to get at the enemy. The 

 best remedy for this and the Nelumbium moth, which is 

 very much like it, is a lamp trap. Any ordinary lamp 

 placed near the plants at night, and standing in a shal- 

 low vesessl containing kerosene, will attract the insects, 

 which, on striking the lamp, fall into the kerosene and 

 are no further trouble. Muskrats are more or less 

 troublesome, especially where Nelumbiums are grown. 

 They will eat the tubers in winter and early spring, and 

 will make sad havoc with banks. They will also eat the 

 roots of some NjTnphseas. The best remedy for these is 

 the steel trap. A sporadic disease has also made its ap- 

 pearance. The leaves are affected with spots, which, 

 under a damp, warm atmosphere, spread rapidly. Such 

 climatic conditions, followed by bright sunshine, cause 

 the affected leaves to shrivel up. This greatly weakens 

 and checks the plants. This disease yields readily to a 

 weak solution of Bordeaux mixture. The same remedy 

 is also very valuable in ridding the pond of all con- 

 fervoid growth. 



Tub Cultuke should be resorted to only from lack of 

 space, or when no other method can be adopted ( Fig. 12.3 ) . 

 For this system of culture, N^Tnpheeas should be selected 

 that are moderate growers, yet free-flowering, and other 

 miscellaneous aquatic plants. The tubs should hold 

 from 4 to 12 cubic feet of soil for Nymphseas, according 



