How Long Does It Take to Grow Cannabis? Realistic Timeline

The short answer: 8-20 weeks from seed to harvest, plus 2-4 weeks for drying and curing. Total time from planting a seed to smoking what you grew is roughly 3-5 months.

The detailed answer depends on three things: whether you're growing autoflower or photoperiod seeds, whether you're indoors or outdoors, and how long you cure.

The quick comparison

Fastest possible (autoflower, indoor): 8-10 weeks seed to harvest + 3 weeks dry and cure = roughly 11-13 weeks total. About 3 months.

Average indoor grow (photoperiod): 4-5 weeks veg + 8-10 weeks flower + 3-4 weeks dry and cure = roughly 15-19 weeks total. About 4 months.

Outdoor grow (photoperiod, northern hemisphere): Plant in May, harvest in October. Roughly 5-6 months including dry and cure.

Breaking it down by stage

Germination: 1-5 days

This is the time from placing your seed in a damp paper towel (or soil) to seeing a seedling break the surface. Most seeds crack within 24-72 hours using the paper towel method. Once planted, the seedling emerges in another 2-3 days.

Seedling stage: 1-2 weeks

The plant develops its first few sets of true leaves. Growth is slow. The root system is establishing itself underground even though the above-ground growth looks minimal. This stage needs the least intervention. Water sparingly, keep the light gentle.

Vegetative stage: 2-8 weeks

This is where the plant builds its structure. Stems thicken, branches multiply, leaves fill out. The length of veg depends on your approach:

Autoflowers have a built-in veg timer. They typically veg for 3-4 weeks before automatically transitioning to flower. You have no control over this, which is part of why autos are simpler to grow.

Photoperiods veg for as long as you keep them on an 18/6 light schedule. Most indoor growers veg for 4-6 weeks, but you can go shorter (for smaller plants in limited space) or longer (for bigger plants with higher yield potential). You trigger flowering by switching to 12/12 light.

Flowering stage: 7-14 weeks

This is when buds form. The length depends entirely on the strain's genetics:

Fast autoflowers: 7-8 weeks of flower. Strains like Critical Mass Auto and Northern Lights Auto finish quickly.

Standard autoflowers: 8-10 weeks of flower. Most popular autos (Gorilla Cookies Auto, Blue Dream Auto) fall here.

Indica-dominant photoperiods: 7-9 weeks of flower. OG Kush, Northern Lights, Purple Punch.

Hybrid photoperiods: 8-10 weeks of flower. Gorilla Cookies, Girl Scout Cookies, Gelato.

Sativa-dominant photoperiods: 10-14 weeks of flower. Amnesia Haze, Durban Poison, some Haze crosses can push past 14 weeks.

Drying: 7-14 days

After harvest, you hang the trimmed branches in a dark room at 18-22C and 55-65% humidity. Rushing this step ruins the flavor and smoothness. A 10-day dry is ideal for most conditions.

Curing: 2-8 weeks (minimum 2)

Dried buds go into glass jars and get "burped" daily for the first week, then every few days after that. Curing breaks down chlorophyll (removes the grassy taste) and allows terpenes to develop fully.

Minimum cure is 2 weeks for acceptable results. 4-6 weeks produces significantly better flavor and smoothness. Some growers cure for 2-3 months for premium quality.

Fastest path to harvest

If speed is your priority, here's the fastest realistic setup:

Grow a fast autoflower strain (Northern Lights Auto, Critical Mass Auto) indoors under 20/4 light. These can finish flowering in 7-8 weeks from seed. Add a 10-day dry and 2-week minimum cure.

Total: roughly 11-12 weeks, or about 2.5-3 months.

You won't get maximum yield or the best possible flavor with this speed run, but you'll have smokable, decent-quality flower faster than any other approach.

What slows things down

Longer veg time (photoperiods). Every extra week of veg adds a week to your total timeline but increases yield. It's a trade-off between speed and harvest size.

Sativa-dominant genetics. Pure sativas and heavy sativa hybrids can flower for 12-14 weeks. Beautiful plants with unique effects, but they test your patience.

Longer cure. The difference between a 2-week cure and a 6-week cure in flavor quality is substantial. If you're growing for personal use and quality matters more than speed, a longer cure is worth the wait.

Plant problems. Nutrient issues, pests, pH problems, and other setbacks can stall growth for days or weeks while the plant recovers. A clean, well-managed grow runs on schedule. A messy one adds unpredictable delays.

Realistic expectations for your first grow

If you're growing indoors with an autoflower strain and you follow a basic guide, plan for about 3.5 months from seed to the first time you smoke what you grew. That includes a reasonable dry and a 2-week cure.

Your first grow will likely take a bit longer than experienced growers report because you'll make small mistakes and learn as you go. That's normal and expected. By your second grow, you'll know your setup well enough to shave time off every stage.

If you want a detailed week-by-week breakdown of every stage with nutrient schedules, training timing, and harvest indicators, the Gorilla Grow Bible covers the full timeline in seven chapters.