How long does it take to grow a plant? May 29, 2020 01:17 Updated Seeds normally take 3-4 months to grow. Clones normally take 2-3 months to grow. Have a specific strain of plant in mind? Check out our app to see detailed grow times for hundreds of plants! Related articles How do I harvest cannabis? What do I need to do while my plant is growing? How many plants can you grow in a Grobo? What cannabis yields can I expect? How many harvests can I get out of a Grobo?