138 
THE FLORIST AND POMOLOGIST. 
[ June, 
seem to flourish best in a light loamy soil, mixed with leaf mould. And 
they need plenty of water, as well as frequent syringing, when growing and 
coming into flower. They are generally cultivated in moist stoves, but will 
flower well in a warm conservatory if planted out, or if grown in large pots, 
or tubs. 
The following sorts I have found the best and showiest of the family:— 
Strelitzia augusta, S. reginse, S. humilis, S. ovata, S. parvifolia, and 
S. angustifolia. 
Welbeclc. William Tillery. 
ON WATERING OUT-DOOR PLANTS. 
>N opinion prevails among gardeners that night is the proper time to 
water plants, and this opinion is generally acted on; but I suggest 
that the early morning is a better time for performing that operation 
—a suggestion which I support by the following arguments. 
Two acknowledged agents in promoting vigorous growth are-heat 
and moisture. Moisture is under our control, but if we exercise that control, 
and water our plants in the evening during dry weather, we do so at the 
expense of a great portion of the heat we desire to preserve. Two influences 
are at that time brought into operation in cooling down the soil and retard¬ 
ing the growth of the plants, which we vainly endeavour to urge forward by 
moisture. These are Evaporation, and Radiation. Now evaporation cannot 
take place unless at the expense of heat, or in other words without produc¬ 
ing cold. Let us look then at the effects of watering in the evening. 
Evaporation goes on briskly, the temperature sinks, and there are no sun’s 
rays to communicate fresh heat; the plants are chilled, and their growth is 
sometimes even less than that of plants not watered at all, but which have 
been allowed to take their chance. The other source of diminished tem¬ 
perature is radiation. Every warm body tends continually to throw off heat 
to all others of lower temperature, near or remote. All objects do not radiate 
heat with equal rapidity, but rough and darkly coloured surfaces do so more 
readily than those which are light and smooth. Now, almost all soils are 
darkened in colour by moisture; hence by watering, the soil is reduced 
to the best possible condition, for getting cooled down during the night. 
Thus the combined influence of evaporation and radiation occasioned by 
evening watering, exerts itself in thwarting the intentions of those who 
heedlessly practise it. 
The best time for watering exposed plants, I consider to be early in the 
morning, as the sun’s rays are then beginning to be felt, and to exert their 
counteracting influence. The darkened surface, that very condition which 
made the soil throw off its heat more readily during the night, causes it to 
absorb the heat of the sun’s rays by day with increased facility, so that 
