The invention is a planar sheet deployment system, primarily for use in cultivating short-day photoperiodic plants such as cannabis. The system is comprised of: a) a sheet of flexible, planar material suitable for being rolled upon itself for storage, the sheet material having upper and lower edges and lateral side edges that are dimensioned to cover a predetermined area when deployed; b) a frame with an upper horizontal support for anchoring the upper edge of the sheet material in a generally horizontal alignment c) a linear winding rod spanning across and bonded to the width of the sheet material along its lower edge in parallel to the upper edge, for winding-up the sheet material into a roll surrounding the winding rod; d) a trackway comprising two separated parallel tracks extending from the upper support downwardly along respective paths that are displaced inwardly from the lateral edges of the sheet material, extending to a lower level, the trackway being positioned for supporting the sheet material as
