WATERING 



the sunshine is very bright is often followed by scald- 

 ing of the foliage unless the plants are well shaded. 

 Ferns, Rex begonias, Chinese primroses and vichardias 

 are among plants easily injured in this way. 



Consider the temperature. The temperature at which 

 the plants are kept, the position of the heating pipes, 

 the amount of light, and the freedom of ventilation per- 

 missible, need to be kept in mind in watering plants in 

 glasshouses. It is better, as a rule, to have the water- 

 ing conform to these conditions ; but frequently the prac- 

 tice must be reversed. 



Experiments by the writer show, beyond question, 

 that the temperature of water used in watering plants 

 exerts a marked effect upon the growth, flowering and 

 fruiting of plants. It is now held that, in general, the 

 water should be of a temperature close to that of the 

 air in the house where the plants are growing, or about 

 10° P. below. 



Watering may be indirect. Shading the glass of 

 greenhouses in summer with some suitable material is 

 much practiced by florists for the purpose of sheltering 

 plants from too great intensity of light, and for the 

 purpose of reducing evaporation and transpiration. 

 Certain kinds of plants, as palms, and some kinds of 

 ferns, require this; also newly potted plants. Syring- 

 ing of walks, by reducing the temperature and increas- 

 ing the humidity of the air, also tends to reduce trans- 

 piration and save watering. Watchfulness and atten- 

 tion to ventilation are necessary, however, to avoid 

 excessive humidity, which tends toward a soft watery 

 growth and extreme sensitiveness and susceptibility to 

 disease. 



Vessels to contain plants should always be provided 

 with openings at the bottom for perfect drainage. 

 This, in a measure, is a safeguard against overwater- 

 ing. Investigation has shown that a soil which is kept 

 continuotisly wet through bad drainage or otherwise is 

 rapidly impoverished through loss of nitrogen. A fer- 

 mentation is also set up in the roots, which through the 

 formation of alcohol and other products, results in their 

 destruction. 



While a constantly wet soil is always very objec- 

 tionable, thoroughness in watering as often as the 

 plants need water is of the greatest importance. When 

 enough water has been supplied there will be more or 

 less dripping from the bottom of the pot. It is a good 

 plan to leave a space of 1K-2 in. or more at the top of 

 the pot for the reception of water. This space should 

 be so large that when filled, the supply of water in soak- 

 ing downward will penetrate to the bottom of the vessel. 



See, also, Greenhouse Management, p. 696. 



WATERMELON 



1967 



2718. Watering 



The can on the left, flattened on the sides, is gen- 

 erally preferable. It can be carried in greenhouse 

 walks and in narrow rows. The long spout enables 

 the operator to apply the water directly to the roots; 

 and the greater force of the discharging water makes 

 a better spray from the rose. 



ments, some of the advantages of this method of apply- 

 ing water. The essential features of this system are 

 a water-tight bench, with earthenware tile placed in 

 rows upon the bottom either crosswise or lengthwise to 

 the bed. Soil is placed about and over these. Openings 

 into the runs of tile are left at convenient points. 

 Water poured into these openings runs along the length 

 of the tile and is carried outward and upward into the 

 soil by capillarity— thus moistening the soil from below 

 upward. In beds over 50 ft. long a fall of 2 in. to every 

 50 ft. is recommended. See Pigs. 1182-3, Vol. II. 



J. C. Arthur has experimented with a plan which, in 

 many respects, is an improvement upon the "tile sys- 

 tem." Here porous brick, having the lower edges 

 cracked off, are placed edgewise and close together over 

 the bottom of the bench. The shattered edge of one 

 brick meets that of its neighbor. A network of channels 

 is thus formed over the bottom of the bed, whereby 

 water is distributed over the entire bottom. Capillarity 

 carries the water upward, through the layer of bricks to 

 the soil resting upon them. The amount of water ap- 

 plied at a given time is indicated by a gauge near the 

 edge of the bench. This consists of a U-shaped tube, 

 placed at some convenient place, having one end in- 

 serted through and on a level with the bottom of the 

 bench; the other rises an inch or so higher outside 

 the edge of the bed. Carnations and lettuce have given 

 excellent results grown by this method of subwatering. 



Subwatering in connection with flower-beds and 

 borders in the open ground has also proved very ad- 

 vantageous. It tends to prevent the formation of a 

 crust on the surface of the soil, and keeps it loose 

 and porous, carrying the soluble plant-foods upward 

 instead of downward. For further notes, consult the 

 article Irrigation. 



Watering Lawns and Flower-Beds. — In watering 

 beds in the open ground, and lawns, the chief thing is 

 thoroughness. Superficial waterings induce the forma- 

 tion of roots near the surface. Neglect and subsequent 

 drought then prove more disastrous than ever. The 

 evening is the best time for surface sprinkling. Wa- 

 tered in the heat of the day, grass and various other 

 plants are likely to have the foliage injured. Ordina- 

 rily it is better to avoid watering beds of plants in the 

 open ground if possible or delay it until really neces- 

 sary, and then water thoroughly. Ernest Walker. 



Plunging.— While it is true that most of the water 

 given to the plant passes through the soil and escapes- 

 from the hole in the bottom of the pot, yet much that 

 is left in the soil, — which is considerable if the soil 

 is saturated as it should be,— is evaporated from 

 the porous sides of the earthenware pots. In warm 

 sunny weather plants in small pots, standing on a bench, 

 dry out very quickly. This can be avoided by plung- 

 ing the pots in some material, as coal ashes, tan bark, 

 or, better than all, spent hops. When plunged to the 

 rims, only half of the surface watering is needed, and 

 the advantage of less watering is shown by a marked 

 improvement in the health and vigor of the plants. 

 Such a benefit is this plunging that plants which would 

 otherwise need a shift into a size larger pot, can be car- 

 ried along another month in perfect health. This ap- 

 plies more particularly to quick-growing, soft-wooded 

 plants, geraniums more especially, for these are quickly 

 exhausted by too frequent waterings. 



William Scott. 



WATEELEAF. Hydrophyllum. W. Lemon. See Pas- 

 siflora lauri folia. W. Lettuce. Pistia Stratiotes. W. 

 Lily. See Nymphaa. W. Milfoil. Myriophyllum. W. 

 Oak. tyuercus nigra, commonly known as Q. aquatica. 

 W. Oat. Zizania aquatica. W. Plantain. Alisma 

 Plantago. W. Plants. See Aquatics. W. Heed. Arundo. 

 W. Pest. Elodea Canadensis. W. Shield. Brasenia 

 peltata. W. Soldier. Stratiotes aloides. W. Thyme. 

 Elodea Canadensis. W. Weed. Elodea Canadensis. 



Subwatering . — A method of watering known as "sub- 

 watering" has been made use of in recent years for 

 supplying moisture to plants growing in beds. W. J. 

 Green, of the Ohio Experiment Station, was one of the 

 first in this country to point out, as the result of experi- 



124 



WATERMELON. Figs. 2719-20. Plate XLIX. The 

 Watermelon (Citrullus vulgaris, which see) is a native 

 of the warmer parts of Africa. It is a tender annual. It 

 has been cultivated from prehistoric times. It reaches 

 its highest development in warm and sunny climates. 



