How Long Does It Take To Grow Weed from Seed to Harvest

It’s one of the first questions a grower asks when he thinks of growing cannabis.

Honestly, there’s no perfect answer to this question.

Growing the herb is pretty straightforward.

However, the amount of time it takes depends on several factors.

The average time to grow cannabis will range anywhere from 4-5 months.

But, to get an exact answer, you’ll need to understand how the strain, environment, and even growing techniques play a role.


How Long Does It Take To Grow Marijuana Outdoors?

Growing marijuana outdoors is completely different than growing it indoors.

Like any other plant, cannabis also grows and flowers according to the seasons.

And contrary to many assumptions, it takes longer to grow this plant outdoors.

If you start growing in the spring, for instance, it might take anywhere from 5-6 months to harvest.

People that grow outdoors can only plant twice a year if all conditions are suitable.

How Long Does It Take To Grow Marijuana Indoors?

Cannabis seeds are divided into two categories including photoperiod and autoflowering plants.

Photoperiod Plants

Photoperiod strains are most preferred even if they take more than four months to harvest.


Simply because it’s forgiving and easy to grow.

Cannabis plants go through their vegetative stage before moving to the flowering phase.

The bigger the plant, the better the yield, obviously.

So, the grower can delay the vegetative phase by supplying 18 hours of light.

Even if you mess up, you will still have time to correct your mistakes.

And the plant will continue to grow as usual as long as you supply enough light.

Once you’re satisfied with the growth, you can switch to the flowering phase.

Most growers usually wait until three months before heading to the flowering phase.

But, it's not uncommon to switch to 12 hours of light when the plant is just two months old.

So, basically, the harvest time depends on you.

If you want the plant to grow huge, you'll need to wait at least three months.

Then, the flowering phase will take about two months, making it a total of 5 months.

Growers that wait only two months before switching can harvest the buds in 4 months.

This is assuming that you're supplying everything necessary for the plant to grow including fertilizers, soil, light, and ventilation.


Autoflowering Plants

If you’re running out of patience, growing autoflowering plants is the best option.

These babies will not yield as much as the photoperiod plants though, mind you.

However, it takes much less space.

And instead of growing one big plant, you can grow several autoflowering plants.

Autoflowering plants are completely different than photoperiod plants.

Here, the amount of light supplied will not matter.

This doesn’t mean that the plant will grow in complete darkness!

But, even if you supply 18-20 hours of light to delay the vegetative phase, the plant will flower within three months.

No matter what you do, the plant will do everything automatically.

However, here comes the kicker.

While photoperiod plants take more than five months sometimes, autoflowering plants are quick.

Some autoflowering strains can be harvested within 8-9 weeks since germination.

Now, before you rush to buy autoflowering seeds, remember that there are some cons too.

The yields will not be as great as photoperiod plants.

Also, beginners will have a hard time growing these strains.

Photoperiod plants are easy to grow, but it takes expertise to grow these girls.

For instance, if you mess up with fertilizers and delay the growth, there’s no turning back.

The plant will flower even if it’s just a couple inches in size.

You cannot manipulate the stages of growth to derive better yields.

Having said that, autoflowers are great if you have a few grows under your belt.

By planning, you can grow several plants and harvest faster to compete with photoperiod plants.

Autoflowering strains tend to stay small, but you can purchase strains that grow bigger.

In fact, strains like Onyx Auto and Super Lemon Haze grow as big as photoperiod strains!

If you want to grow only photoperiod strains and also reduce the harvest time, you must consider a few factors.

Provide More Light in the Vegetative Phase

The more light you provide, the better the plant grows during the growing/vegetative stage.

This is true for both autoflowering and photoperiod strains.

Some growers provide only 16 hours of light.

However, a plant that receives 20 hours of light every day will grow faster.

You can even supply 24 hours of light!

The plant will surely grow monstrous and cut your waiting time.

This allows the grower to switch to the flowering phase quickly and thereby reduce the harvest time.

Reduce Light in the Flowering Phase

Another trick is to supply less light during the flowering phase.

When a grower switches to the flowering phase, he goes by the 12/12 cycle.

12/12 cycle indicates that the plant gets 12 hours of light and 12 hours of darkness.

You can reduce the light in the flowering phase to only 10 hours.

This process increases stress and forces the plant to mature faster.

Stress is sometimes a good thing.

However, be careful with this technique because timing matters.

If you supply only 10 hours of light as soon as you switch to the blooming phase, you’ll have a tiny plant on your hands.

Your yields will reduce considerably.

So, ensure that you use this technique ONLY after the plant has adjusted to the flowering phase for at least two months.

Choose Strains That Flower Faster

It's always best to do your research before buying seeds.

From super-high THC levels to short flowering strains, you can purchase any strain that satisfies you.

Even if you want to grow only photoperiod strains, you can choose strains that flower faster.

For example, Northern Lights is a strain that grows tall and huge.

But, it needs only nine weeks in the flowering phase to be harvested.

You can supply 22-24 hours of light in the vegetative stage.

And when the plant grows big enough, you can switch to the 12/12 cycle.

By choosing a strain that flowers faster, you don’t need to increase darkness and risk small yields.

As you’ve probably deciphered by now, there’s no specific time period to harvest cannabis plants.

It's all a matter of choice, and you can alter your preferences to achieve what you truly want.

Tony Hand Jr

Tony Jr is the Founder and Editor-in-Chief of If he’s not smoking, writing or watching anime, then you can usually find him on the couch yelling over terrible play calling.

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