How Long to Grow Marijuana

How Long Does it Take to grow a Marijuana Plant?

Short answer:

Marijuana typically takes 4 – 7 months to grow.  The time for marijuana to reach maturity and harvest depends upon several factors, the two most important being the proper application of light and nutrients.

The Stages of Marijuana Plant Growth

  1. Germination / Germinating:       1-7 days (1 week)
    • Keep seeds warm and moist.  Seedlings appear within a week.
  2. Seedling / Vegetative:                  28 – 56 days (4 – 8 weeks)
    • 18 – 24 hours of light per day. Plant grows stems and leaves.
  3. Flowering / Reaching Maturity: 56 – 70 days (8-10 weeks)
    • 12 hours of light per day to start plant flowering (buds).
    • Feed “bloom” booster nutrients.
  4. Harvest and Cure Flowers / Marijuana Buds (1 – 3 weeks)
    • Harvest when bud-hairs darken and curl inward.
    • Dry in a cool dark, low-moisture area for about 5 – 7 days.
    • Additional curing of cannabis buds will improve quality.

How Long Does Cannabis Take to Grow? – A More In-depth Guide to Growing Marijuana

Time Table to Grow Weed, from Seedling to Harvesting

1) GERMINATION (1 WEEKS)

  • Select healthy mature seeds that are shiny, dark-to-light brown, and hard to the touch. ( Immature seeds that are white-to-light green and soft will not germinate. )
  • To germinate marijuana seeds, keep them moist in a dark area.  Placing cannabis seeds between wet paper towels / napkins is a common practice to keep the seeds moist.  Then, place them in a dark room, closet, or cupboard.
  • A primary root called the radicle will begin to grow.  When placed in soil, the radicle will push downward into the soil becoming a tap root and anchoring the seedling.
  • Learn more about the initial stages of germination and seedling growth: https://www.britannica.com/science/radicle

How Long to Grow Cannabis?


2) SEEDLING (2 – 3 WEEKS)

  • As the seedling grows epicotyl and cotyledon tissue will push upward out of the soil.
  • The first leaves will form gathering energy from sunlight.
  • The seedling requires 18 – 24 hours of sunlight per day.
  • Keep soil moist and maintain mild humidity for healthy growth.
  • Avoid over-watering.
  • Maintain adequate air movement and ventilation to avoid mold or other problems.
  • The seedling becomes a plant when it develops leaves with a full number of “fingers”, typically between 5-7.  Some marijuana strains produce more.
Marijuana Leaf with Seven (7) “Fingers”

2) VEGETATIVE (2 – 7 WEEKS)

  • As the seedling matures to a plant, it is time to transplant to a larger pot with well-draining soil where the plant will grow to maturity, beginning with the vegetative stage.
  • During vegetation, plant growth soars so it is important to pay attention to water and nutrient needs. Avoid overwatering.
  • Plant stems become thicker and longer, more leaves and branches form, and the plant will grow to approximately 2 – 3 feet tall.  Ensure your plants have sufficient space and air circulation.
  • Plant growth is largely determined by the rate at which leaves collect and transform light through photosynthesis. At this stage, plants should receive 18 hours of light and 6 hours of dark to rest.
  • To induce the next phase, flowering, the hours of light are reduced.

3) FLOWERING (8 – 10 WEEKS)

  • By reducing the duration of light received from 18 to 12 hours per day, the plant moves from the vegetative stage to the flowering stage (some refer to this stage as “pre-flowering”).
  • Plant growth will cease, and energy will move toward producing flowers and the beginning stages of marijuana buds.
  • Marijuana plant gender matters. Only female weed plants can produce high potency THC marijuana buds.
  • To identify the gender of the cannabis plant, you must examine what grows in between the nodes. The nodes are the part of the plant where the branches extend from the stalk of the plant. Male plants will have small pollen sacs for the purpose of spreading seeds while the female plant will have stigmas, which catch the pollen that male plants spread. It is best toidentify the sex of the plant before the plant’s reproduction cycle become active. Usually, it is possible to determine the sex of the plant by 4-6 weeks into plant growth.
How to Tell the Difference Between a Male and Female Marijuana Plant

Source: https://thegreenfund.com/male-vs-female-marijuana-plants

4) HARVESTING / CURING (1 – 3 WEEKS)

  • How do you know when to harvest a marijuana plant?
    • Leaves begin to yellow and curl. Some may fall off.
    • Marijuana buds are plump and developed. Branches hang more.
    • “Hairs” (flower pistils/stigma) begin to turn reddish-orange.
    • Thrichomes (sticky droplets) turn from clear, to opaque, to amber.
Mature Marijuana Flower Ready for Harvesting
  • FLUSHING: If growing marijuana using nutrients, you should “flush” your cannabis plants, which means you stop using nutrients and only water for about 2 weeks before harvesting.  Flushing your plant helps produce smoother, more enjoyable marijuana.  For more information, see this fantastic article How to Flush Your Indoor Cannabis Plants on GrowWithJane.com.
  • HARVESTING: Tools needed for harvesting: gloves, scissors/shears, rubbing alcohol (recommended).
    • Remove branches with buds and separate from the rest of the plant, which may be discarded.
    • Remove leaves from each branch. Gently trim leaves from the marijuana buds.
    • Hang leave-free branches with trimmed-buds to dry for 10 – 14 days. Ensure sufficient air circulation.
    • After approximately 14 days of drying, remove the buds from the branch and trim-off any remaining dried leaves or leaf-fragments.
    • CURING: (2 – 3 weeks) Place the dried marijuana buds in sealed jars. For the first 2 weeks of curing, briefly open the jars for 30 – 60 minutes, then reseal. 
  • CONGRATULATIONS!  YOUR CROP IS READY TO ENJOY!