If you need to determine the sex of your plants (to discard the males), they will start showing sex organs a few weeks into the veg stage. It’s imperative to separate males so they don’t pollinate the females.
Once your seed has germinated, or sprouted, it’s ready to be placed in a growing medium, like soil. The tap root will drive down while the stem of the seedling will grow upward.
The first marijuana plant stage begins with the seed. A cannabis seed should feel hard and dry, and be light- to dark-brown in color. An undeveloped seed is generally squishy and green or white in color and likely won’t germinate.
Flowering stage length: 8-11 weeks
It’s important to know these stages and how long each lasts to know what the plant needs and when. Knowing where your cannabis plants are in their life cycle will dictate when to prune, train, and trellis your plants, and when to harvest.
Buds typically grow the most toward the end of the flowering life cycle. You probably won’t notice much budding out at the beginning of the flowering stage, and it will slow down toward the end of the cycle, when buds become fully formed.
Marijuana light cycle: 16 hours a day
If growing male and female cannabis seeds, they’ll start to show their sex organs, or “pre-flowers,” after 8-10 weeks from germination.
But if the seed you found looks decent, you might as well germinate it and see what sprouts.
As interest in CBD as a medicine has grown, many breeders have crossed high-CBD hemp with cannabis. These strains have little or no THC, 1:1 ratios of THC and CBD, or some have a high-THC content along with significant amounts of CBD (3% or more).
Transplanting germinated cannabis seeds
Additionally, every long-time grower will tell you that clones degrade over time.
CBD, or cannabidiol, is one of the chemical components—known collectively as cannabinoids—found in the cannabis plant. Over the years, humans have selected plants for high-THC content, making cannabis with high levels of CBD rare. The genetic pathways through which THC is synthesized by the plant are different than those for CBD production.
For the typical homegrower, it may be easier to obtain cannabis seeds rather than clones. Growing from seed can produce a stronger plant with more solid genetics.
Check out Johanna’s full video series on how to grow weed on Leafly’s YouTube .
• Seedling stage
Time: 10–15 days
Now that you have an idea of how long it will take to grow weed indoors, we can start to break down some of the specifics so you can get the most out of your operation.
How long it takes for cannabis to mature its buds can vary greatly depending on genetics. Some indicas bred for speed can be ready after 5–7 weeks of bloom. However, the average flowering time for most indicas and hybrids is usually 7–10 weeks depending on the strain.
A DETAILED TIMELINE ON CANNABIS GROWTH
• Germinating your seeds
Time: 1–7 days
3. Vegetative stage (2–8+ weeks) – The vegetative stage could last indefinitely if we’re talking photoperiod (non-autoflowering) strains. Most growers let their plants vegetate for a month or two, or until their plant has a reached a certain size. Bigger plants can mean bigger yields, but how long you veg depends on available growing space.
• Time to grow cannabis (8 weeks–7+ months) – The time needed to grow weed from the moment you germinate your seeds until harvest; includes the four growing phases of cannabis:
This covers the entire cannabis life cycle from germination all the way through to harvest.