The cellar culture
Everywhere over there, where winter can be downright cold, so the temperatures are below freezing for a long time, there are difficulties with accommodation. To ensure even larger collections, relatively cheap and without major maintenance work for the heating to get over the unfavorable season, the United States has switched to the combined cellar culture. In the warm season, the plants are cared for outdoors under large trees. If in early autumn the night temperatures fall below + 10° C drop, the plants come under artificial light in a prepared basement room. The conditions are, however, the conditions of the cellars of modern country houses, so relatively dry, airy and slightly tempered by the return of the hot water heating. Cold, damp and draughty cellars of old houses are not suitable.
The following information is taken from a report on successful placement in the basement. The room was painted entirely with white rubber paint. The plants are on about 1,10 m high tables, 70 The fluorescent lamps are installed cm above them. The leaves are enough 7 to 15 cm to the light sources and get an illuminance of 13000 to 18000 Lux. This is only possible with lamp units with reflectors, which must always be kept very clean. The air is humidified by evaporation of water from shallow pools filled with gravel; also by an electric humidifier, which is coupled with a small fan, with which the necessary air movement is achieved at the same time. Fresh air is supplied through a window, namely at night, to ensure the required drop in temperature by about 7 °. This is said to be an important prerequisite for good success. The plants are sprayed over once a day and watered as needed. 6 In the morning the lights go off, Fan and humidifier on. To 13 1/2 Hours the light turns off, the fan continues to run, the window is opened more or less depending on the outside temperature. The return of the hot water heating is the only heating source next to the low heat effect of the fluorescent tubes. In December the exposure will be on 12 Hours reduced and gradually returned to May 13 1/2 Hours increased. Then the transition to the open air takes place.
In the Central European climate, general treatment without glass protection is only possible for a few hard species. The transition would therefore have to take place in a small greenhouse, but with caution, there is a sudden strong daylight- or exposure to the sun can cause burns.
According to the present report, the health of the plants is excellent; they bloom abundantly, the flowers are – probably as a result of the strong exposure to light – well educated, firm and durable.