Quick pick
Pick indoor first if you grow 1 to 6 plants, live in a state with plant count limits, or need a harvest date you set. Indoor costs more per gram. It removes rain, wind, and most weather risk from the grow.
Pick outdoor if you have yard space, a frost-free season of 5 months or more, and a budget under $400. Outdoor plants use sunlight at no cost. They also reach sizes that indoor tents cannot hold.
Soil vs Hydroponics for Cannabis
Indoor: numbers
A 4x4 ft tent needs 400 to 480 W of LED light. At 18 hours veg and 12 hours flower, a 480 W light pulls about 260 kWh per month in veg. At the US average of about 17 cents per kWh, that is about $44 per month. Add a fan and filter at 30 to 60 W. Total electricity lands near $50 to $70 per month.
how long does it take to grow cannabis
Setup cost: $600 to $1,200 for tent, light, fan, filter, pots, and timer. Yield: 4 to 8 oz per plant is a common range for 4 plants under a 480 W LED in a 4x4. Light quality and canopy management move that number.
- Climate: 70 to 80 F in veg, 65 to 75 F in flower, 40 to 60% relative humidity.
- Pests: fungus gnats and spider mites. Fewer entry points than outdoors.
- Cycle: 10 to 14 weeks from seed to harvest for photoperiod plants.
Outdoor: numbers
Outdoor costs: $150 to $400 for pots, soil, nutrients, and stakes. Sunlight costs nothing. Water use in a 20 gallon pot runs 2 to 5 gallons per plant per day in hot weather.
Yield: a 6 ft plant in a 20 gallon pot can produce 1 to 2 lb of dry flower in a good season. Plant size drives yield. A late start or a short season cuts that number.
- Season: plant after the last frost. Harvest from late September to October in most US zones.
- Risks: rain at harvest, bud rot, caterpillars, deer, and theft.
- Cycle: 5 to 7 months from seed outdoors in a temperate zone.
Side by side
- Control: indoor. Light, temperature, and humidity stay in range.
- Cost per gram: outdoor. Sunlight and soil beat electricity.
- Yield per plant: outdoor. Plants reach 6 ft and more.
- Pest and mold risk: indoor. Fewer vectors and no rain.
- Legal exposure: indoor. Smell and plant counts stay inside. Check state rules first.
How to pick
Choose indoor if any of these is true: you have a plant count of 6 or less, you rent, you need a harvest before October, or your summers are humid. Choose outdoor if you have a yard, a frost-free window of 5 months or more, and a dry fall.
Middle path: a greenhouse or a light-deprivation tarp. It uses sun for most of the day and pulls a tarp to force flower. Cost: $300 to $800.
Legal note
Home grow rules vary by state. Some states ban home grow. Some cap plants at 6 per adult. Check your state law and local code before you buy a light or a pot.