how fast does weed grow indoors

Marijuana light cycle: indoor—16 hours a day; outdoor—at least 6 hours of direct sunlight (“full sun”), plus several hours indirect sunlight.

Harvest happens sometime between September and November. This depends on your local climate, as well as the weather that particular year—one year it could be the end of September, the next, end of October, and growers in the Pacific Northwest will have to pull down their crops earlier than those in Northern California.

Marijuana light cycle: 16 hours a day.

We can’t stress enough that the timeframes in the above graphic are ranges of time for the Northern Hemisphere. You’ll need to adjust them based on your specific region and local weather and climate.

If you’re growing indoors, you can force a weed plant to flower after only a few weeks when it’s small, or after several weeks when it’s big. If you’re growing outdoors, you’re at the whim of the seasons and will have to wait until the sun starts to go down in fall for it to flower and then to harvest.

Seedling stage.

Outdoors, flowering occurs naturally when the plant receives less light each day as summer turns into fall. Indoor growers can trigger the flowering cycle by reducing the amount of light marijuana plants receive from 16 to 12 hours a day.

At this stage, the plant is vulnerable to disease and mold. Keep its environment clean and monitor excess moisture. Be sure to give it plenty of light.

Seedling stage length: 2-3 weeks.

The weather will start to turn and the sun will begin descending in the sky as your plants fatten up with sweet, sticky buds. It might be tempting, but wait until around the Fall Equinox to start harvesting.

Once your seed has germinated , or sprouted, it’s ready to be placed in a growing medium, like soil. The tap root will drive down while the stem of the seedling will grow upward.

If you need to determine the sex of your plants (to discard the males), they will start showing sex organs a few weeks into the veg stage. It’s imperative to separate males so they don’t pollinate the females.

The vegetative stage of cannabis is where the plant’s growth truly takes off. At this point, you’ve transplanted your plant into a larger pot and the roots and foliage are developing rapidly. This is also the time to begin topping or training your plants.

The Spring Equinox is a good reminder that it’s time to kick off the outdoor growing process and start germinating your seeds.

Everything should be cleaned up, dried, and curing well before the Winter Solstice. Now’s a good time to make your own cannabutter, topicals, or tinctures with all that trim from the harvest. Kick your feet up, relax, and hunker down for the cold, it’s been a long growing season!

There are a number of changes to consider once plants go from the vegetative stage to the flowering stage:

When should you grow marijuana?

Seed germination length: 3-10 days.

Two rounded cotyledon leaves will grow out from the stem as the plant unfolds from the protective casing of the seed. These initial leaves are responsible for taking in sunlight needed for the plant to become healthy and stable.

Take meticulous notes on when and how you perform each step, as well as what the weather is like. Other notes can include how much water you give plants, at what intervals, and how much nutrients you give them. Pictures will also give you a better sense of how your plants look along the way.

The flowering stage is the final stage of growth for a cannabis plant. This is when plants start to develop resinous buds and your hard work will be realized. Most strains flower in 8-9 weeks, but some can take even longer, especially some sativas.

Be mindful to increase your watering as the plant develops. When it’s young, your plant will need water close to the stalk, but as it grows the roots will also grow outward, so start watering further away from the stalk in the soil so roots can stretch out and absorb water more efficiently.

Flowering stage length: 8-11 weeks.

Within the flowering stage, there are three subphases:

What are a weed plant’s growth stages?

Cannabis plants are considered seedlings until they begin to develop leaves with the full number of blades on new fan leaves. A healthy seedling should be a vibrant green color.

As the sun reaches up high in the sky, your cannabis will want to as well. Make sure all of your plants are outside by the Summer Solstice.

The biggest variability in how long a marijuana plant takes to grow will happen in the vegetative stage—after the seedling phase and before flowering.

Buds typically grow the most toward the end of the flowering life cycle. You probably won’t notice much budding out at the beginning of the flowering stage, and it will slow down toward the end of the cycle, when buds become fully formed.

The first marijuana plant stage begins with the seed. A cannabis seed should feel hard and dry, and be light- to dark-brown in color. An undeveloped seed is generally squishy and green or white in color and likely won’t germinate.

When your marijuana plant becomes a seedling, you’ll notice it developing more of the traditional cannabis fan leaves. As a sprout, the seed will initially produce leaves with only one ridged blade. Once new growth develops, the leaves will develop more blades (3, 5, 7, etc.). A mature cannabis plant will have between 5 or 7 blades per leaf, but some plants may have more.

If you buy a clone from a grower or breeder it will be a seedling, so you can skip the seed germination phase.

Marijuana light cycle: 16 hours a day.

Light emitting diode (LED) technology has been around for a while, and they are getting more efficient all the time. The main drawback to LED grow lights is their cost: well-designed fixtures can cost 10 times what a comparable HID setup would.

The first step in odor control is making sure temperature and humidity are under control in your grow space—high temperature and humidity will perpetuate odors.

You will definitely want to invest in a timer for your lights. Because the amount of light a plant receives dictates its vegetative or flowering stage, it’s important to give it a consistent amount of light every day, and that’s done with a timer. It’s a good idea to check your timer at least once a week to make sure it’s working properly.

Fluorescent grow lights.

Plants need fresh air to thrive and carbon dioxide (CO2) is essential to the process of photosynthesis. This means you will need a steady stream of air flowing through your grow room, which will allow you to move hot air out of the space and bring cool air in.

It’s also a good idea to have oscillating fans to provide a constant breeze in your grow room as it will strengthen your plants’ stems, making them stronger and healthier.

Odor becomes much more difficult to manage in the final six weeks of a marijuana plant’s life, when trichomes and terpene production ramps up. You can also get odor-absorbing gels, which replace weed smells with other scents. Keep in mind that odor gels don’t eliminate odors, but simply mask them.

Terra cotta pots offer a unique set of benefits to growers in hot climates.

Cannabis, like all plants, prefers certain environmental conditions in order to thrive. Temperature, humidity, light intensity, and airflow are all factors that will need to be monitored and regulated in order to keep cannabis healthy through its different phases.

You’ll need a dedicated space for your marijuana plants—you won’t be able to move them around. Ideally, the space is next to a window so you can vent air from the grow space outside. Growing weed plants smell! Especially when flowering kicks in, you’ll want to redirect air so your house doesn’t reek of weed.

Check temperature and humidity levels.

Check out our Guide on nutrients for more info.

For growers who have a little extra money to spend and want full control over their indoor garden, environmental controllers will allow you to automate the process. These devices are essential for if you’re away from the garden for a long period of time.

You’ll need to ensure that temperatures remain within a comfortable range for your plants, between 70-85°F when lights are on and between 58-70°F when off. Some varieties of cannabis—generally indicas—prefer the colder side of the range, while others—typically sativas—are more tolerant of high temperatures.

Humidity is the amount of water vapor in the air. Here are some ways to control it in your marijuana grow room:

Timers/Automation.

These are quickly becoming the standard. Roots in fabric pots grow to the outer edges and attempt to bypass the porous fabric wall but are cut back, allowing new growth to occur. This process, called “air pruning,” results in a denser root composition which promotes healthy growth and development.

Generally speaking, it takes anywhere from 10-32 weeks, or about 3-8 months, to smoke what you’ve grown. (It’ll be quicker if you start with a clone or an autoflower seed.)

As your indoor weed plants grow, they’ll need less attention, but you’ll still need to check up on them every 2-3 days.

Different lights produce different colors of light. Here’s a brief rundown of the most popular types of cannabis grow lights used for indoor growing.

Inevitably, there will be fluctuations of temperature and humidity in your cannabis garden. These fluctuations can occur both throughout a grow space as well as within pockets inside a given room. They can also occur at different points within a given day or throughout a season as conditions change in the environment outside your grow space.

This plant didn’t spend any time in the Vegetative Stage. It was given 12-12 lighting almost immediately after sprouting. It’s so small that it spent its whole life in a solo cup, and its only light came from CFLs. I weighed down the bottom of the cup so it didn’t fall over. It ended up yielding about 0.75 oz.

The Average Indoor Cannabis Grow Takes 3-5 Months.

This includes the time needed to grow your cannabis plant from seedling to harvest plus an additional 2 weeks (or more) which is used to cure your cannabis buds after harvest (making them more potent and better smelling).

Before You Start Growing Weed.

So, after you’ve bought seeds and equipment, grown a plant from seed to harvest, trimmed, dried and cured your buds, that brings us back to the original answer…

Here’s the breakdown…

That’s why most cannabis growers won’t give you a straight answer. The truth is, there are many factors will affect the total time until you have ‘ready’ buds, by days, weeks or even months. This includes your strain, your setup, and how big you plan to grow your plants (bigger plants need more time!). So instead of giving you a huge range, an easier-to-swallow answer might be to say that the average grow takes 3-5 months for indoor growers.

Your plant will likely double in size (maybe a bit less, maybe more) from when you first put it into the flowering stage; this is known as the Flowering Stretch. So make sure you end the vegetative stage before your plant reaches half the final height you want, or your cannabis plants may outgrow your grow space during the flowering stage!

Short (6-8 weeks)

Two weeks is considered the minimum time to cure your buds, but I personally cure all my buds for a month or even a bit longer because the buds continue to improve for several more weeks.

Total preparation time needed: Up to a few weeks.

Time Needed to Grow Weed, From Seedling to Harvest.

Get seeds or clones: 0-4 weeks: If you’ve found seeds in your bud or have instant access to genetics (like knowing a grower or buying seeds/clones locally), you’re already good to go. If you order from a seed bank overseas (especially US residents), expect to wait 1-4+ weeks to get seeds. Shipping time depends on the shipper and how fast the mail gets delivered. Sometimes seeds get caught up in customs for weeks. Make sure to always order from a trustworthy vendor.

Here’s the breakdown…

Utopia Haze is a mix of Brazilian landrace strains.

Total post-harvest time needed: 2.5 weeks – 1.5+ months.

These cannabis plants were vegetated for about 9 weeks before being flipped, in the exact same setup as above, and produced over 10 ounces each. Besides an extra week of veg, the biggest difference between this grow and the one above was simply the strains.

Post-Harvest (before you smoke you should do this stuff too)

Additionally, for at least the first time you grow, you also need to consider the time needed to get your equipment and seeds/clones.

Get equipment: 0 days – 2 weeks This includes purchasing your equipment and/or waiting for it to show up in the mail. This goes much quicker if you buy everything locally, for example at a hydroponics shop. Once you have your marijuana growing supplies, you’ll need to setup your growing area and equipment. A standard setup should take an afternoon at most. Depending on how you purchase your equipment and how quickly you setup, you could be ready the same day or in two weeks (after factoring in shipping time).

Frisian Dew plant growing outdoors with deep purple buds.

It’s actually a really good question! Every new marijuana grower should know how much work they’re signing up for! The short answer is…

If you haven’t started growing your own weed yet, today is the day!

Here’s the breakdown…