An account is given of a system for and a method of making the growth/thriving conditions for grass more favorable in connection with grass pitches, e.g. football pitches. A lighting unit having a rectangular peripheral shape and thin, disc-like form is dimensioned to correspond to the pitch that is to be lit artificially, and may comprise extra devices for additional functions that may improve the growth/thriving of the grass, such as watering/ventilation. The lighting unit (16) is arranged to be moveable in the vertical direction by means of a hoisting arrangement comprising masts (10) (or stand roofs), wires (20) and powered hoisting apparatuses.