Indoor Cannabis Growing Basics

Why Grow Indoors?

Indoor cannabis cultivation allows complete environmental control: consistent temperature, humidity, lighting, and nutrient delivery regardless of outdoor conditions. Indoor grows produce multiple harvests per year, allow year-round cultivation in any climate, enable growing rare or exotic strains unavailable locally, and provide privacy and security. The trade-off is cost — electricity, equipment, and supplies represent real operating expenses that increase with grow size.

Core Environmental Parameters

Four variables control indoor grow success: Light (intensity, spectrum, photoperiod), Temperature (70-82°F during light, 60-70°F during dark), Humidity (60-70% seedling/veg, 40-50% flower), and CO2 (ambient 400 ppm is sufficient for most home grows; supplemental CO2 benefits are only significant at very high light intensities). Monitor all four variables with a combo thermometer/hygrometer. Controlling these parameters consistently is more important than any single equipment choice.

Basic Feeding Schedule

Cannabis needs different nutrient ratios at different growth stages. Vegetative: high nitrogen, moderate phosphorus and potassium (e.g., 3-1-2 NPK ratio). Early flower: reduce nitrogen, increase phosphorus and potassium (e.g., 1-3-2). Late flower: reduce all nutrients to allow natural senescence (use water only the final 1-2 weeks). Start at 25-50% of recommended nutrient doses and observe plant response before increasing. Yellowing lower leaves during late flower is normal nitrogen senescence, not a deficiency.

Watering Best Practices

Watering frequency depends on container size, medium, plant size, and temperature. The "lift test" is reliable — lift the container when dry and when just watered to feel the weight difference. Water when the medium is dry 1-2 inches below the surface in soil. Water to about 15-20% runoff to prevent salt buildup. Use pH-adjusted water (6.0-7.0 for soil). Overwatering is the most common beginner mistake and causes root rot, nutrient lockout, and slow growth.