A growing chamber adapted to grow at least a portion of a plurality of plantstherein, aninlet duct leading into the growing chamber, an outlet duct leading out fromthe growingchamber, the growing chamber being sealed from its surroundings except for theinlet andthe outlet. A method of growing at least a portion of the plants in thegrowing chamber, caninclude :raising the relative humidity level in the growing chamber to atleast 45 %,lowering the relative humidity level in the growing chamber to below 45%, andrepeatingthe steps of raising and lowering at least five times during 9 single day.
