How To Harvest As Soon As Possible
5 min

How Long Does It Take To Grow Cannabis?

5 min

Perhaps the most frequently asked question from novice cannabis growers is how long will it take to grow my cannabis? With our simple guide you will understand the cannabis life cycle and know what to expect from plants

How long does it take to cultivate a cannabis crop? This is the question on the tip of every newbie grower's tongue. We’ve been there before, even grandmaster cannabis growers started out as novices once upon a time.

So how long does it take to grow cannabis? The short straight answer is 3-4 months with good quality feminised seeds diligently cultivated in optimal conditions.

Many variables, from genetics to cultivation methods, play huge roles in the cannabis life cycle. Outdoor cannabis cultivation of photoperiod strains, i.e. marijuana that flowers in a 12/12 light/dark cycle, can take longer than 6 months to bring a late blooming sativa strain to harvest.

That’s provided Mother Nature is generous with her blessings, ensuring ideal climatic conditions prevail for the duration of the grow.

Knowledge really is power. Before plunging in and getting your hands dirty straight away, it’s advisable to do a little desk research first.

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Books, blogs, magazines or even YouTube videos, whatever is your preferred media, it’s always best to “study under many teachers because a teacher can only take you as far as they themselves have gone”. – Dr. Richard Alan Miller, author/herbalist/former trainer of Navy SEALs.

Heed the advice of reliable sources with decades of cannabis cultivation experience. Do some field research if you have access to a local cannabis club or association.

Use the best tools available that best suit you and your grow show. Also, don’t be afraid to experiment, but don’t get carried away if you’re not especially “green fingered”.

The following stage by stage guide is a handy reference for cannabis cultivators of all levels to make sure your grow show is on the right track, and will help you avoid getting derailed on the journey to a heavy harvest.


Fail To Prepare And Prepare To Fail

Before you go into hunter-gatherer mode, pause and come up with a plan. Once you have decided on your cultivation method and selected a strain or strains to grow, you must invest in the key ingredients of cannabis cultivation.

Prepare a budget and allow a couple of weeks before you are all set to get started. Most growers purchase their kit online these days for convenience, discretion and value, so don’t forget to factor in delivery times.

When it comes to seeds, especially feminized seeds, purchase high-quality genetics from reputable breeders and distributors exclusively. Knock-offs and hermaphrodites spoil the cultivation experience and produce lousy weed.

Outdoor cultivation can be accomplished with a relatively minimalist kit and basic nutrients. However, indoor cultivation can be as simple or as complicated as you make it.

Similarly, it can be a costly endeavor, but there are also plenty of bargains to be found. Our advice is to hunt for bundle deals from trustworthy online growshops on grow tents, lighting systems, hydroponic systems and nutrient packs.

Latest grow tech like LED systems are rapidly emerging as the dominant new technology on the market, replacing HID lighting similar to the way CDs led to the obsolescence of cassette tapes. So it’s no surprise LED kits are generally more expensive than old school HPS and MH lamp setups.

However, they are more economic to run, have a longer lifespan, and convert far more energy into light rather than heat, making for easier environmental control.

Don’t get it twisted, some of the best dope we’ve ever smoked has been grown under HID lights, but the fire bud of the future will be cultivated indoors with LEDs.


Getting Your Grow On: Germination And Seedlings

Step one is to germinate your precious beans. This is a relatively simple process and if you use the “paper towel method” you will see tap roots bursting out in as little as 24-48 hours. For specific instructions on all 3 proven germination techniques see this link.

Once they burst forth to the surface with a pair of tiny little leaves and delicate stem, your beans have transitioned to cannabis seedlings.

The best conditions for these infant plants for the next 7-14 days is inside a grow tent with 18-24 hours of light (preferably white light, CFL bulbs work fantastic), temperatures between 20-25°C and high humidity in the 50-70% range.

There is a range of propagation tools out there that can make this stage a lot easier to manage.


Vegetative Growth

All cannabis can be cultivated with a 12-12 light-dark cycle, in fact with as little as 8 hours of light hardy ruderalis strains can endure. We recommend far more comfortable treatment of cannabis plants.

Sativa strains may only require a further week or two under 18+ hours of light before inducing flowering or plant height could become unmanageable later in the bloom cycle.

In contrast, indica strains typically require 4-6 weeks as they are generally stockier bushes and need time to fill out. Hybrids are a great option for novices and veteran cultivators alike as they can race through vegetative growth, becoming vigorous branchy beasts in as little as 2-3 weeks with 18+ hours of light.

Applying training methods and/or pruning for yield, techniques like topping or FIMing will usually require a prolonged vegetative stage regardless of the strain as all plants require recovery time to respond to these practices.

Some strains respond better and faster than others, in general terms if your number 1 aim is high yield: SOG for indica and pruning or LST followed by ScrOG for sativa’s.

Hybrids are versatile and respond well in a variety of systems too.
If you seek efficiency, then think about a second grow tent or grow room dedicated to vegetative growth; with minimal investment you can take advantage of crop rotation.


Flowering Stage

Photoperiod cannabis strains will only enter the bloom phase with light reduction. In nature this is more gradual, which is why outdoor cropping is seasonal, with crops ripening in the autumn.

Indoors, adjusting your timers to 12/12 is how you induce flowering.
Always pay attention to the breeder’s description of the cannabis strain you choose to grow to get an idea of the expected flowering time, growing characteristics and genetic background.

Indica-dominant strains typically bloom in 7-9 weeks, hybrids 8-10 weeks and mostly sativa strains like Neville’s Haze and Amnesia Haze can be a real patience tester with flowering taking 12+weeks.

Further reducing light to 10 hours can hurry along a particularly late blooming strain or help an impatient grower shave some time off the bloom cycle. This expedites ripening, but it also reduces harvest weight.


Harvesting, Drying And Curing

Harvesting cannabis is the culmination of all your hard work. Be patient and keep your eye on the trichomes; harvesting too early will reduce yields and potency too. Harvesting too late can ruin the high, particularly if you’re looking for an uplifting buzz.

Take care to manicure your marijuana carefully. Whether you’re using a simple trimming scissors or pro trimming tools, pay attention to removing as much leaf material as possible without spoiling the buds.Toss away the fan leaves and save that quality trim in a paper bag for making hash from it later.

Dry your marijuana in a dark and dry place. Popcorn buds and trim leaves can be dried relatively quickly in 3-5 days in basic brown paper bags stored in the wardrobe.

The bulk of your harvest should be dried slowly and carefully over a period of 10-15 days. You’ve got lots of options and the grow tent can easily be repurposed with the addition of a drying rack.

Drying nets are really effective too. Just make sure the humidity is low, ideally 40% or less and room temperature or a little below is perfect. The box from your new pair of runners with a few air holes poked through the top can be a great drying box.

If you simply cannot resist any longer or have depleted your stash, well, feel free to sample the fruits of your labour after two weeks drying. It’s no harm to sample at this stage just to make sure everything is delicious, potent and free from mould.

Curing is the final process to get the absolute maximum flavour and potency from your marijuana buds. This can take anywhere from a few weeks to a few months. We have put together a comprehensive guide to drying and curing your cannabis properly, so check it out.

If you are in the market for some high-end curing jars, then we implore you to check out the CVault and our review of it - it is well worth the investment.

If you can keep your patience and complete this process we congratulate you and recommend a tasty spliff to celebrate.


Let'S Not Forget Autoflowering Cannabis

Autoflowering cannabis has begun to enter a renaissance of sorts. Cannabis ruderalis was once considered the ugly duckling of the Cannabis family tree. In the last five years the new generations of autoflowering genetics have become genuine rivals to traditional photoperiod cannabis varieties.

Autoflowering strains are the fastest flowering type of cannabis. They are not photoperiod-sensitive when it comes to flowering, rather they will enter the bloom cycle regardless of the light cycle within 4-6 weeks of growth from seed.

Autoflowering strains thrive in 18+ hours of light and have amazing unique selling points. Autoflowering plants are the fastest, hardiest and most versatile cannabis plants. For inexperienced growers and outdoor growers growing in unfavourable conditions and/or out of season autos are a blessing.

Some can be harvested in just 8 weeks from seed and produce decent yields of potent 15%+ THC level marijuana. Virtually every seed bank is offering a wide selection of autoflowering strains to cater to the phenomenal demand from growers of all levels for the new emerging force in cannabis gardens.

Whatever you grow, however long it takes, give it your absolute best effort and remember practice makes perfect.

Adam Parsons
Adam Parsons
Professional cannabis journalist, copywriter, and author Adam Parsons is a long-time staff member of Zamnesia. Tasked with covering a wide range of topics from CBD to psychedelics and everything in between, Adam creates blog posts, guides, and explores an ever-growing range of products.
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