It certainly pays off to keep even the darker places in your grow area in mind, the ones that the primary light source might not fully reach. It would be a shame if all the plants didn't have the perfect opportunity to grow and flower. If you place a light vertically into a corner, it will shine even on the bottoms of the leaves, where the overhead light source would not ordinarily reach. Supplemental lights increase the intensity of light and help you and your plants reach a greater yield.
Additional lights are also often used for germinating plants or seedlings. They are also popular with growers who clone plants with cuttings. Small supplemental lights are an excellent help for the mother plant and the cuttings themselves. For this purpose, your best choice is a fixture emitting UV light. They are suitable for propagators and low growing spaces with limited ventilation. Outdoor growers and gardeners commonly use additional lights during the winter months, in the mornings and early evenings.
Grant your plants the benefits of a year-round summer with supplemental lighting.