Grow Lights Guide: Everything You Need for Indoor Growing

Most vegetables and herbs need 12-16 hours of light per day. Seedlings: 14-16 hours for strong, stocky growth. Leafy greens (lettuce, spinach): 12-14 hours. Fruiting plants (tomatoes, peppers): 14-16 hours plus high light intensity. Herbs: 12-14 hours for most, less for shade-tolerant types. Use a timer to maintain consistent light/dark cycles. Plants also need darkness (6-8 hours minimum) for proper growth - don't run lights 24/7 as it stresses plants and wastes energy.

Distance depends on light type and intensity. LED panels: 12-24 inches for seedlings, 6-18 inches for mature plants (follow manufacturer guidance). Fluorescent tubes: 2-4 inches above plants (they run cool and don't burn). High-intensity LEDs: 24-36 inches. Signs lights are too close: bleached or burnt leaves, curling away from light. Signs lights are too far: leggy, stretched growth reaching toward light. Start higher and lower gradually, watching plant response. Many LEDs are adjustable - start at 50% intensity for seedlings.

LED advantages: 50% more energy efficient, last 50,000+ hours (vs 10,000 for fluorescent), produce less heat, can be tuned to specific spectrums, more compact. Fluorescent advantages: Lower upfront cost, proven technology, tubes are replaceable, work well for seedlings and low-light plants. For most indoor gardeners in 2026, LED is the better choice despite higher initial cost - the energy savings and lifespan pay for themselves within 1-2 years. Fluorescent still works great for simple seed starting setups.

Full spectrum lights provide a range of light wavelengths similar to natural sunlight, including blue (400-500nm for vegetative growth), red (600-700nm for flowering/fruiting), and some green/yellow. Plants use primarily blue and red light, but some green helps penetrate leaf canopy. 'Full spectrum' has become marketing jargon - what matters is the light has both blue and red components in appropriate ratios. For vegetables, look for lights emphasizing blue (for leafy growth) and red (for fruiting). Pure white LEDs work well for most plants.

Regular white LED bulbs can supplement natural light but aren't ideal as primary grow lights. They work for: low-light houseplants, herbs on windowsills, and extending daylight hours. They're less effective because: lower light intensity than grow lights, spectrum not optimized for plant growth, spread pattern wastes light. Budget hack: Multiple cool-white and warm-white LED bulbs (5000K + 2700K mixed) can work for seedlings and greens if positioned close. For serious growing, dedicated grow lights deliver much better results per watt.

Electricity cost depends on wattage and hours used. Example calculations at $0.12/kWh: 20W LED panel, 14 hours/day = ~$1/month. 100W LED panel, 14 hours/day = ~$5/month. 200W LED setup, 14 hours/day = ~$10/month. 4-foot fluorescent fixture (64W), 14 hours/day = ~$3.20/month. LED lights have dropped dramatically in both price and operating cost. A decent seed-starting setup costs $2-5/month to run. Even a productive indoor vegetable setup is typically under $15/month in electricity.