A LED grow-light system is disclosed. The LED grow-light system includes dual-layer grow-light canopies with linear LED light bars to provide upward and downward lighting in a central illumination area. The LED light bars are preferably configured to move up and down relative to a grow bed through stepper motors attached to the grow-light canopies and vertical pole structures for supporting the grow-light canopies over the grow bed. The LED light bars include modulated LEDs, or LED arrays, to provide uniform light distribution over the grow bed while maintaining grow-light canopy footprints that are similar in size to the grow bed.