Honestly, I just hesitate to say because I get so much grief. I basically use one per plant to supplement my garage/outdoor grow in eastern San Diego. Ima tell ya this - my garden likes these easy bulbs - SANSI Grow Light Bulb with COC Technology, PPF 65.6 umol/s LED Full Spectrum, 36W Grow Lamp (400 Watt Equivalent) with Optical Lens for High PPFD, Energy Saving Plant Lights for Seeding and Growing https://www.amazon.com/dp/B07BRKG7X1/