Abstract: An installation for cultivating plant cultures comprising a cover device for protecting the ground at which the plants are grown from damaging radiation of the sun, and a support device for supporting the cover device. The cover device comprises a number of pivotable, substantially cylindrical parabolic reflectors. Along the focal lines of these parabolic reflectors there is arranged a respective conduit for conveying a heat carrier. An adjustment mechanism pivots the reflectors about their lengthwise axis. A circulation system for the heat carrier is provided and encompasses a conveyor or feed pump and the aforementioned conduits. A control device actuates the adjustment mechanism and is structured such that when the sun is shining the reflectors are automatically positionally adjusted in accordance with the position of the sun and at the same time the ground is shaded and the energy of the sun absorbed by the reflectors is removed.