How many hours of light do cannabis plants need?

Seedling/Veg: 18 hours on, 6 hours off (18/6). Flower (photoperiods): 12 on, 12 off (12/12). Autoflowers: 18/6 or 20/4 throughout entire grow — they flower automatically regardless of light schedule.

3 comments

3 Comments

Experienced1mo ago

Went through this exact scenario. Fixed it by adjusting watering schedule and it bounced back in 3 days.

Seedling1mo ago

I'd add: don't overthink it. Cannabis is resilient. Start simple and learn as you go.

Grower1mo ago

Bookmarking this for reference. Super helpful for beginners.