The short answer
Cannabis is a fast-growing annual. Give it a legal place to grow, strong light, a loose well-draining medium, steady airflow, water when the top inch of soil dries out, and nutrients matched to the stage of growth. Vegetative plants want 18 hours of light and 6 of dark. Flowering plants want 12 and 12. Most indoor runs finish in 3 to 5 months from seed.
That is the whole cycle in one paragraph. Everything below is detail you can dial in as you go.
cannabis growing guide for beginners
Check the law before the light goes on
Home growing in the US runs through state rules, not one national rule. Many legal states allow a small number of plants per household, often six, with a cap on how many can be mature at the same time. Some legal states do not allow home grow at all. Medical patients sometimes get a higher count.
how long does it take to grow cannabis
Read your state cannabis authority page and your lease. Growing over the plant count, or in a rental that forbids it, turns a hobby into a real problem.
Seeds or clones?
Seeds give you variety and a long shelf life. Clones give you a known result and a shorter veg time, since a clone is a cutting from a female plant. You already know the sex and roughly how it will grow.
Two terms matter on the seed pack. Photoperiod strains flower when the light schedule flips to 12/12. Autoflowers flower on their own clock, usually 8 to 10 weeks from sprout, and ignore the light schedule. Autos are forgiving for a first run, though the yields are smaller.
Buy from a seller who lists breeder, genetics, and expected flowering time. Bag seed is a lottery ticket.
Indoor or outdoor
Outdoor plants get free light and huge root space. They also get pests, weather, and an October harvest. If you live somewhere humid, the last two weeks can turn into a mold clinic.
Indoor gives you control over light, temperature, humidity, and smell. It also costs money for electricity, ventilation, and gear. A 2x2 or 4x4 tent is a solid indoor starting point.
The basic kit
- Grow tent or a light-sealed room
- LED or HID light sized to the space
- Inline fan and carbon filter for airflow and odor
- Pots in the 3 to 7 gallon range, fabric pots work well
- Soil or coco plus a nutrient line
- pH meter, thermometer, and hygrometer
- Timer
- Shears, a drying rack, and jars for curing
Germinate and start the seedling
Drop the seed in a glass of water for 12 to 24 hours, then move it to a damp paper towel or straight into a small pot of soil about a quarter inch deep. Keep it warm, around 70 to 80F.
Roots show in 2 to 7 days. Once the first true leaves appear, keep the light gentle and the distance generous. Seedlings burn under a strong LED that sits too close.
Vegetative stage
This is the building phase. Under 18/6 light, the plant stacks stems, fan leaves, and root mass. Feed nitrogen-heavy nutrients at half the label strength at first. Water deep, then let the medium dry back.
Low stress training helps here. Bend the main stem down and tie it so side branches rise to the same canopy height. More bud sites end up in direct light. Topping once or twice does something similar.
Airflow matters. A gentle moving breeze builds thicker stems and keeps mold from settling in later.
Flowering
Flip the timer to 12 hours on, 12 off. The plant stretches for the first two weeks, so leave headroom for the light. Buds form over the next 6 to 10 weeks depending on strain.
Switch to bloom nutrients and back off the nitrogen. Keep humidity in the 40 to 50 percent range and watch for buds touching each other. Dense wet clusters are where bud rot starts.
Check trichomes with a jeweler's loupe. Cloudy with some amber is the common harvest window. Clear means you are early.
Harvest, dry, cure
- Cut the plant and hang whole branches in a dark room at about 60F and 60 percent humidity.
- Dry for 7 to 14 days until small stems snap instead of bending.
- Trim and move buds into jars, filling them about three quarters of the way.
- Burp the jars once a day for the first two weeks, then about once a week.
Curing is not optional. Two to four weeks in the jar smooths out the harshness that freshly dried flower has. Store jars in a dark, cool spot.
Mistakes that cost you a run
- Overwatering. More first grows die from wet roots than from anything else.
- Full-strength nutrients too early.
- A light that is too close or too weak for the tent size.
- No airflow during flower.
- Harvesting by calendar instead of by reading the plant.
- Letting the smell escape. A carbon filter is not optional in an apartment.
What to expect from a first run
Expect problems. A little leaf discoloration, a stretched stem, a pH drift. Most of it is fixable, and most first-time growers still end up with something worth smoking. Take notes on what you fed, when you watered, and how the plant responded. The second run is where the results get good.