How Long Does It Take to Grow a Marijuana Plant?

The Typical Marijuana Growth Timeline

So how long does it actually take to grow a marijuana plant? The short answer is: it depends. On average, you’re looking at anywhere from 8 to 16 weeks from seed to harvest, but that number can change depending on the strain, the setup, and how hands-on you are.

Some people grow autoflowering strains, which are kind of the go-to if you want a faster grow time. These plants usually finish up in about 8 to 10 weeks, start to finish. No need to mess with light schedules — they flip into flowering on their own after a few weeks. If you’re trying to get in a quick harvest, autoflowers are solid.

Photoperiod strains take a little longer, but you get more control. You decide when they move from the vegetative stage to the flowering stage by changing the light cycle. That means you can veg them longer for a bigger yield, but it also means your grow might stretch out to 12 to 16 weeks depending on how you do it.

The grow cycle itself has a few key phases: germination, seedling, vegetative, and flowering. Each stage has its own vibe and timeline. Germination only takes a few days, but the vegetative stage can last a few weeks or longer if you let it. Flowering usually takes around 6 to 10 weeks, and that’s when the real action happens — the buds develop, trichomes show up, and you start thinking about harvest.

If you’re growing outdoors, the timeline shifts around the seasons. Most outdoor growers plant in spring and harvest in the fall, usually around late September or early October. It takes longer overall, but you get the sun doing half the work.

The average grow time really depends on your setup and what kind of cannabis seeds you’re working with. But no matter how you grow, the process is all about timing and paying attention to your plant’s signals.

Indoors vs Out

Like all plants, marijuana plants thrive outdoors, but indoor gardens can take their growth to the next level. 

Indoor cannabis gardening allows you to have complete control over the atmosphere, you can dictate temperature, humidity, water, nutrition, and when the light cycle changes to trigger the switch from vegetative to flowering stage.

A main benefit to growing indoors over outdoors, your cannabis garden can grow year round. Outside, marijuana plants are beholden to the natural cycle of light and dark, and buds begin to form sometime around the end of June when the daylight hours begin to dwindle after the summer solstice. Generally speaking, most marijuana strains are ready for harvest sometime mid to late October. Wait too long and the cooler weather can have significant impacts on your final product. 

Marijuana planted outdoors may take slightly longer to grow, but purists tend to weight the benefits over the cons: 

• The sun is the ideal light source, providing all the spectrums a marijuana plant needs to thrive;
• When not confined, cannabis plants can breathe and take advantage of fresh air and natural circulation;
• Taking into consideration the above, outdoor gardening is significantly cheaper, as you aren’t paying for expensive equipment or electricity. 

A Closer Look at the Flowering Stage

Although every part of a marijuana plant’s life cycle is important, the flowering stage is the most exciting, as its during this period when marijuana plants truly shine (literally and figuratively). Below, a rough guide to what you can expect as your marijuana baby undergoes one of its final transformations: 

• Weeks 1 & 2 Plants will make the transition from vegetative to flowering
• Weeks 3 & 4 You’ll begin to notice “budlets” forming at the nodes where the leaves meet the stem 
• Weeks 5 & 6 The buds begin to get fatter, and you will notice more as they develop along the length of the stalk and lower branches
• Weeks 6 to 8 Buds start to “ripen”, crystals begin to form along the surface of the flowering sites and leaves, and the delicate white pistils will start to darken
• Weeks 8 and beyond As budding sites get fatter and pistils turn from white to brown, you will begin preparing your plants for the final flush (to remove excess food and nutrition and improve the overall taste) and harvest. 

When you can’t wait 

They say good things come to those who wait and its true – the longer you allow your marijuana plants to “do their thing”, the better your finished product. But, if you can’t wait that long, you may want to consider the following strains in your therapy garden: 

• Northern Lights – in addition to being a totally well-rounded and easy-to-grow marijuana strain that’s suitable for beginners, Northern Lights is also pretty quick on the draw, and flowers within 7 to 9 weeks. 
• OG Kush – a strain that should be on everyone’s bucket list, OG Kush is a potent marijuana that offers up an above average yield within about eight weeks of flowering. 
• Hash Plant – considering Hash Plant credits Northern Lights as one of its parents, it should come as no surprise this densely budding plant can be ready for harvest within as few as 40 days of flowering. 
• Gigabud – another offspring of a Northern Lights cross, fruity Gigabud will be finished flowering within 50-60 days and will produce a hefty crop of extremely sticky buds. 
• Critical Kush – this indica-dominant hybrid only needs 50-60 days of flowering to produce a monstrous yield of 21 ounces per square meter of heavy-hitting weed. 

Thanks to modern breeding techniques, many of your favorite strains now come in autoflowering varieties, so be sure to keep an eye on what’s available when you’re ready to start your garden growing. 

Factors That Affect Grow Time

There’s no one-size-fits-all answer to how long it takes to grow weed, mostly because a bunch of stuff can change your grow time. From the type of cannabis seeds you start with to the setup you’re using, little things can make a big difference.

First off, strain type matters a lot. Autoflowering strains are way faster than photoperiod ones. Autoflowers usually start flowering on their own after a few weeks and are ready to harvest in around 8 to 10 weeks total. Photoperiod strains take longer since they don’t flip to flowering until you switch up the light cycle. That extra control is cool if you want bigger plants, but it can also drag the whole process out.

Your grow environment is another big deal. An indoor grow gives you more control over things like temperature, humidity, and light, which usually means fewer surprises and a slightly faster grow. You can flip to flowering whenever you’re ready, which is super useful if you’re trying to hit a specific timeline. On the other hand, an outdoor grow relies on natural sunlight and the seasons. That means your plants might take longer to finish, but you won’t have to babysit every little detail as much.

Lighting is huge, especially for indoor setups. Photoperiod plants need around 18 hours of light during the vegetative stage, then 12 hours once you want them to flower. Get the light schedule wrong and it can slow things down or even confuse your plant. With autoflowers, the light cycle isn’t a big deal — they’ll do their thing regardless — but more light usually means better growth.

Nutrients and soil quality also play a role. If your plant isn’t getting what it needs, it’s going to grow slower or get stunted. Too much or too little of the right stuff can mess with the timeline, especially during the flowering stage. Same goes for watering. Overwatering or letting your plant dry out too much can throw off the whole cycle.

Even things like plant training — topping, LST, or other grow techniques — can affect how long it takes. Sometimes training your plant slows it down at first but leads to a better yield later, so it’s a trade-off.

Bottom line: your strain, your setup, and how you treat your plant all factor into the grow time. Some people harvest in two months. Others take closer to four. You’ve just gotta know what you’re working with and plan accordingly.