12 
WATERING 
Many growers aim at running their carnation soils on the dry side. This practice probably developed 
because of the widespread prevalence of stem rots and the tendency of these rots to be more serious 
in moist soils. However, permitting carnation soils to become unduly dry hardens plants and prevents 
optimum growth and production. For profitable operation it is better to rely on the more direct methods 
of preventing stem rots (see section on Diseases and Insects) and to water sufficiently and frequently 
enough to assure free growth. 
“Avoid splashing and wetting the foliage.” Insofar as this is possible it is good advice, for some diseases 
are spread in this manner. Water carefully and do not wet the foliage unnecessarily. However, the lower 
leaves are almost bound to be splashed, and it is advisable to take the following steps which minimize 
the dangers of wetting the foliage and spreading disease: 
1. Water on bright days and complete watering as early in the day as possible so the foliage 
will dry rapidly. 
2. Ventilate freely when watering and after watering to keep down humidity and encourage 
drying of the foliage. 
3. In conjunction with liberal ventilation, when outdoor temperatures permit, turn in additional 
heat to speed the rate of drying moisture on the foliage. 
During the summer months, on new and two-year plantings alike, water sufficiently to maintain active 
growth. Otherwise, the plants become checked and hardened and never entirely regain their lost 
momentum. 
TEMPERATURE 
A night temperature of 50° F. is optimum for carnations. Lower temperatures reduce and delay produc- 
tion, and higher temperatures reduce quality, particularly during the winter when daylight is inadequate. 
For the occasional cloudy day, a daytime temperature of 55° F. is satisfactory. During prolonged periods 
of cloudy weather it is better to hold the day temperature approximately the same as night temperature, 
50° F. 
During bright weather, daytime temperatures of 60 to 65 degrees are compatible with a 50° night 
temperature, 
The importance of uniform temperatures can hardly be overemphasized. Fluctuating night temperatures 
are associated with splitting of flowers. This is particularly evident in early fall when boilers are not 
started up for the occasional cold nights. Two or three nights when the temperatures drop to the lower 
forties increase the incidence of splitting for several weeks. The value of automatic heat and tempera- 
ture controls in carnation houses has been well established. | 
LIGHT 
In most carnation growing areas light is the limiting factor to maximum growth, production and quality 
during the winter months. Carnations should have the lightest house or bench available, and the glass 
should be kept clean. In areas where summer heat is intense, some shading of the glass helps quality 
on benches which are in summer flower production. In those same areas, if the house is well ventilated, 
it is not desirable to shade houses in which carnations are not in crop. 
When field plants are benched in midsummer, the glass is shaded for a week or two, while the plants 
are recovering from transplanting shock. As soon as they are established, the shade should be removed. 
In contrast with this shading requirement for field plants, it has been found feasible to bench rooted 
cuttings direct from the sand during warm weather, without shading the glass. With strong, vigorous 
cuttings, losses have been virtually nil, and the young plants develop rapidly, 
Supplementary artificial light hastens bud development, but also weakens stems and reduces flower 
petalage, and hence has found no place in commercial production. 
