SearchAsk us anythingarrow rightHow long should I keep my plant in the dark before harvest?You must give your plants ready to be grown. 36 hours of complete darkness (to also avoid the collapse of THC).Let's Get It Fixed!Our virtual experts can diagnose your issue (for free!) and resolve simple problems.Chat with a live expertChat nowCall 1 (855) 466-3948Call nowRATESHARECopy linkTwitterFacebookmagnifying glassLink copied to clipboard.SUBMIT AN ANSWERShop Recommended ProductsShop HomeX Recommended ProductsRELATED QUESTIONSHow long should you keep a candle lit?The candles should not be burned for more than four hours at a time. It is recommended that, after being burned for four hours, the candles be turned off, cooled for two hours and cut before turning on again.How long does Roundup stay in the soil?According to Cornell University, half of the product can take one to 174 days to degrade on the ground.How many days can a plant go without light?In general, most plants need at least 6-8 hours of light per day (some lights, some indirect), but some only thrive 10-14 hours of light.How long should you use a light therapy lamp?Duration. With a 10,000 lux light box, light therapy usually involves daily sessions of about 20-30 minutes. But a lower intensity light box, like 2,500 lux, may require longer sessions. Check the manufacturer's instructions and follow the doctor's instructions.How long should you leave a plant light on?Leave the growth light on for 16 hours a day. Turn it on in the morning immediately after dawn and turn it off 16 hours later. Plants also need eight hours of darkness. An easy way to get there is to connect the growth light on a programmable timer.