The invention relates to a greenhouse-type flexible cover element (200) for a crop shelter (700), intended to be fixed on a frame (702) of said crop shelter (700) on the side represented by at least one of the longitudinal edges (206) thereof, characterised in that, on the side represented by at least one of said longitudinal edges (206), there are at least two openings (2061- 2063), termed attachment openings, offset in a perpendicular direction to said longitudinal edge (206), and each intended to receive an elongate attachment element (710). The invention also relates to a crop shelter (700) provided with such a flexible cover element (200).