How many hours should I run grow lights?

Most houseplants thrive with 12-14 hours of grow light per day. Seedlings need 14-16 hours. Succulents and cacti prefer 12-14 hours. Use a timer to maintain consistent light schedules — inconsistent lighting stresses plants. Always provide 8-10 hours of darkness, as plants need dark periods for essential metabolic processes.

Can grow lights replace sunlight entirely?

Yes, with sufficient PAR output and proper duration. Many plants grow exclusively under artificial light in offices and interior spaces. The key is providing adequate PPFD for the specific plant species. High-light plants like fiddle leaf figs and bird of paradise need strong grow lights; pothos and snake plants thrive under almost any grow light.

Best Indoor Plant Grow Lights 2026