If you’re thinking about growing at home for the first time, this is probably one of your first questions. The honest answer is that it depends on a few key factors — but none of them are complicated. Here’s what actually determines your timeline from seed to harvest.
The Short Answer
Most cannabis plants take somewhere between 8 and 20 weeks from seed to harvest. That’s a wide range, and where you land within it comes down to three things: whether you’re growing indoors or outdoors, whether you’re growing autoflower or photoperiod seeds, and how long you choose to let your plants grow vegetatively before flipping them into flower.
I’ve been growing for over a decade, and I can tell you that the timeline is one of the most predictable parts of the whole process. Once you understand the growth stages, you’ll know almost exactly when your harvest is coming.
The Growth Stages (and How Long Each One Takes)
Every cannabis plant moves through the same basic stages regardless of seed type or environment. Here’s what to expect.
Germination: 1–7 Days
This is where it all starts. You plant your seed, keep it warm and moist, and wait for it to crack open and push out a taproot. Most healthy seeds germinate within 2–3 days, though some can take up to a week. If nothing has happened after 7 days, that seed probably isn’t viable.
Seedling Stage: 1–3 Weeks
Once your seed sprouts and pushes above the soil, you’re in the seedling stage. The plant is small, fragile, and developing its first sets of true leaves. During this time, your main job is to not overdo it — light watering, mild light, and patience. This stage typically lasts 1–3 weeks.
Vegetative Stage: 2–8+ Weeks
This is where things start to diverge depending on what you’re growing and how you’re growing it. During vegetative growth, your plant is focused entirely on building structure — stems, branches, and leaves. It’s not producing flowers yet.
For autoflower seeds, this stage is short and automatic. The plant will grow vegetatively for roughly 2–4 weeks before it transitions to flowering on its own, regardless of your light schedule. You don’t control this timeline — the genetics do.
For photoperiod seeds, you have full control. Indoors, your plants will stay in veg as long as you keep them on a long light cycle (typically 18 hours of light, 6 hours of dark). You decide when to flip them to a 12/12 light cycle to trigger flowering. Outdoors, the plant stays in veg through the long days of summer and naturally transitions to flower as the days shorten in late summer and fall.
Most indoor growers veg their photoperiod plants for 4–8 weeks, depending on how large they want them before flowering. A longer veg means a bigger plant with more potential bud sites, but it also means a longer total grow time.
Flowering Stage: 6–12 Weeks
This is the stage everyone’s waiting for — when your plant starts producing actual buds. Flowering time is largely determined by genetics. Some strains finish in 7–8 weeks of flower, while others need 10–12 weeks to fully mature.
Autoflowers typically flower for 5–8 weeks. Combined with their short veg stage, this gives you a total seed-to-harvest time of roughly 8–12 weeks.
Photoperiod plants generally flower for 7–12 weeks depending on the strain. Add in the veg time, and you’re looking at a total grow time of 12–20 weeks indoors. Outdoors, this is dictated by the seasons — you’ll plant in spring, veg through summer, and harvest in fall, usually around late September to November depending on your climate and latitude.
Drying and Curing: 2–4+ Weeks
A lot of growers forget to account for this, but your timeline doesn’t end at harvest. After you cut your plants, you’ll need to dry them for about 7–14 days in a cool, dark space with good airflow. After that, curing in jars for at least 2 weeks (and ideally 4+ weeks) is what takes your buds from decent to great. Curing improves the smoothness, flavor, and overall quality of your flower.
Indoor vs. Outdoor: How the Environment Affects Your Timeline
Indoor Growing
The biggest advantage of growing indoors is control. You set the light schedule, which means you decide when flowering starts (with photoperiod seeds). This lets you plan your grow timeline with a lot of precision.
A typical indoor grow with photoperiod seeds looks something like this: 1 week for germination and early seedling growth, 4–6 weeks of veg, 8–10 weeks of flower, and 2–4 weeks of drying and curing. That puts you at roughly 15–21 weeks from seed to smokable flower.
With autoflower seeds indoors, you’re looking at a shorter window: 8–12 weeks from seed to harvest, plus drying and curing. Total time is closer to 10–16 weeks.
Outdoor Growing
Outdoor grows are tied to the seasons. You plant in spring (after the last frost), your plants veg through the long days of summer, and they begin to flower naturally as daylight decreases in late summer. Harvest usually happens between late September and early November, depending on your strain and location.
For photoperiod seeds outdoors, you’re looking at roughly 5–7 months from planting to harvest if you plant in spring. Autoflower seeds grown outdoors can be harvested in as little as 10–12 weeks regardless of the season, which is why some growers plant multiple rounds of autos in a single outdoor season.
One thing worth noting — outdoor grows don’t give you the same control over timing as indoor setups. Weather, pests, and light pollution can all affect your timeline. But the tradeoff is that sunlight is free, and outdoor plants can grow large and produce significant yields without the electricity costs of an indoor setup.
Autoflower vs. Photoperiod: The Timeline Difference at a Glance
| Autoflower | Photoperiod (Indoor) | Photoperiod (Outdoor) | |
|---|---|---|---|
| Veg stage | 2–4 weeks (automatic) | 4–8 weeks (you decide) | Spring through midsummer |
| Flowering stage | 5–8 weeks | 7–12 weeks | Late summer through fall |
| Seed to harvest | 8–12 weeks | 12–20 weeks | 5–7 months |
| Total with dry/cure | 10–16 weeks | 15–24 weeks | 5–8 months |
The shorter timeline of autoflowers makes them appealing, especially for new growers who want results sooner. But photoperiod plants give you more flexibility and generally produce larger yields because they have more time to develop.
At Triangle Hemp, we carry both photoperiod and autoflower seeds across THCa, CBD, and CBG varieties. If you want a faster turnaround, an autoflower like Purple Lemonade Auto is a great option — stunning purple colors and citrus flavors with a shorter seed-to-harvest window. If you want more control over plant size and yield, a photoperiod strain like Sour Diesel gives you that flexibility. And if you’re growing for CBD specifically, check out our CBD seed collection. Either way, understanding the timeline for what you’re planting makes the whole process less stressful.
What Can Make Your Grow Take Longer (or Shorter)?
A few real-world factors can shift your timeline in either direction.
Strain genetics are the biggest variable. Some strains are bred to finish faster than others, and this is baked into the plant’s DNA. When you’re choosing seeds, the breeder’s estimated flowering time is a good reference point.
Light intensity and schedule matter indoors. More consistent, higher-quality light can help plants develop faster during veg. And with photoperiod plants, the sooner you switch to 12/12, the sooner you’ll harvest — though with a smaller plant.
Growing conditions like temperature, humidity, and nutrient management can slow things down if they’re off. A stressed plant may stall growth or take longer to mature. This is one of the reasons I always tell new growers that the most important thing you can do is spend time with your plants. The more you observe, the faster you catch problems before they set you back.
Growing medium can also play a role. Hydroponic setups can speed up vegetative growth compared to soil because nutrients are delivered directly to the roots. But for most home growers, soil works great and the timeline difference is minimal.
Plan Your Grow Before You Plant
The best thing you can do is set realistic expectations before you start. If you’re growing photoperiod seeds indoors, plan for roughly 4–5 months from seed to cured bud. If you’re running autoflowers, you can cut that closer to 3 months. Outdoor growers should work backward from their expected first frost date to determine when to plant.
Knowing the timeline takes the guesswork out and lets you focus on what actually matters — spending time with your plants and dialing in the basics.
If you have questions about timelines for any of our strains, feel free to give us a call – (919) 410-6945 — we’re always happy to talk through your grow plan.
Frequently Asked Questions
How long does it take to grow autoflower cannabis from seed to harvest?
Most autoflower strains take 8–12 weeks from seed to harvest. They transition from vegetative growth to flowering automatically, without needing a change in light schedule. Add another 2–4 weeks for drying and curing, and you’re looking at roughly 10–16 weeks total before your flower is ready.
How long does it take to grow photoperiod cannabis from seed to harvest?
Indoor photoperiod grows typically take 12–20 weeks from seed to harvest, depending on how long you let your plants grow vegetatively before flipping them to flower. Outdoors, photoperiod plants follow the natural seasons — planted in spring and harvested in fall, which can be 5–7 months. Drying and curing adds another 2–4 weeks.
Does it take longer to grow cannabis indoors or outdoors?
Outdoor grows generally take longer because you’re working within the natural growing season. Indoor grows give you full control of the light schedule, so you can start flowering whenever you choose. However, outdoor plants often grow larger and can produce bigger yields because they have access to natural sunlight for extended periods.
What’s the fastest way to grow cannabis from seed?
Autoflower seeds grown indoors offer the fastest path to harvest — typically 8–12 weeks from seed. If speed is your priority, choose an autoflower strain and provide consistent light (18–20 hours per day) with proper watering and nutrition.
Why does drying and curing take so long?
Drying removes excess moisture from your harvested buds, which typically takes 7–14 days. Curing is a slower process where buds are stored in sealed jars and burped periodically to allow remaining moisture to equalize and chlorophyll to break down. Proper curing improves the smoothness, taste, and overall quality of your flower. Rushing this step is one of the most common mistakes new growers make.
Can I speed up the flowering stage?
Not significantly. Flowering time is primarily determined by the plant’s genetics. You can support healthy flowering by providing the right light intensity, maintaining proper temperature and humidity, and making sure your nutrients are dialed in — but you can’t rush the biology. Harvesting too early results in less potent, less developed buds.
About the Author
Matt, Co-Founder of Triangle Hemp – Matt has been growing plants commercially since 2013, starting with Endless Sun Farms before co-founding Triangle Hemp in 2017 alongside childhood friend Chase. Over more than a decade, Triangle Hemp has produced and sold over a million seeds to home growers, homesteaders, and hemp farmers across the United States. Matt and Chase manage seed selection person
