how long does it take to grow marijuana indoors

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

The growth stages of marijuana can be broken down into four primary stages from seed to harvest:

Be sure to keep a grow journal to track the progress of your plants. Looking back on your notes will help you learn from mistakes and maximize the quality and quantity of your buds.

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.

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.

Seedling stage.

Vegetative stage length: 3-16 weeks.

Within the flowering stage, there are three subphases:

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

Marijuana light cycle: 16 hours a day.

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.

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.

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.

Marijuana light cycle: 16 hours a day.

Even if growing outdoors, a lot of growers will start their seeds inside under an artificial light to help them through this delicate stage of marijuana growth.

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!

Important dates for growing marijuana outdoors.

Flowering stage length: 8-11 weeks.

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.

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.

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.

Marijuana light cycle: 12 hours a day.

Be very careful to not overwater the plant in its seedling stage—its roots are so small, it doesn’t need much water to thrive.

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.

Notes on marijuana growth phases.

Seed germination length: 3-10 days.

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.

Vegetative plants appreciate healthy soil with nutrients. Feed them with a higher level of nitrogen at this stage.

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’re growing outdoors in the Northern Hemisphere, growers usually get their seeds between February and April, and you should start your seeds by the end of April. Some growers will start their seedlings inside in a more controlled environment because seedlings are more delicate, and then put their seeds in the ground outside once they’re a little bigger. If you’re growing clones or autoflowers, you have a grace period of another month or so. Plants usually need to be outside, in the ground, by the end of June.

As roots develop, the stalk will rise and you’ll begin to see the first iconic fan leaves grow, at which point your cannabis plant can be considered a seedling.

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.

Seedling stage length: 2-3 weeks.

Fluorescent light fixtures, particularly those using high-output T5 bulbs, are quite popular with small-scale cannabis growers because:

One trick to avoid hot temps is to have the grow lights on during the evening, when it’s cooler outside, and leave the lights off during the day when it’s hot. This may help bring down the temps, but you’ll only be able to work on the plants at nighttime when the lights are on.

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.

HID.

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.

There are many different media to choose from, including good ol’ fashioned pots full of soil, rockwool cubes, a hydroponic tray, and more.

Remember, a common mistake newbie growers make is to overwater plants.

These come in different shapes and sizes and are a great way to get rid of odor in an indoor weed grow. Also known as “carbon scrubbers” for their ability to get contaminants out of the air, these employ activated and highly ionized carbon to attract particulates responsible for carrying odor, such as dust, hair, mold spores, and volatile organic compounds, and traps them in a filter.

Check out our buying guide on indoor lights for more info.

Getting the right climate for your plants can be a delicate balance involving multiple pieces of equipment and also lots of electricity. This is part of what makes growing weed indoors more expensive than growing outdoors.

How to set up an indoor grow room.

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.

For small spaces or tents, clip-on fans can be attached to structures like walls, corners, or support beams. For larger grow rooms, use medium-sized oscillating fans or big floor models.

Inexpensive options include standard plastic pots or cloth bags, while some growers choose to spend more on “smart pots” or “air pots”—containers designed to enhance airflow to the plant’s root zone.

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.

Indoor climate.

Plants need 18 hours of light a day when in the vegetative stage and 12 hours a day when flowering. The reduction in light from 18 to 12 hours a day is what triggers the flowering cycle—when weed plants start to grow buds.

The two main types of HID lamp used for growing are:

HID (high-intensity discharge) lights are the industry standard, widely used for their combination of output, efficiency, and value. They cost a bit more than incandescent or fluorescent fixtures, but produce far more light per unit of electricity used. Conversely, they are not as efficient as LED lighting, but they cost much less.

If you’re growing in a cold, wet basement, you might have to run a dehumidifier or heater to stabilize the environment. Conversely, if your space is too hot, you might need to add extra fans or an AC to cool the plants down.

You’ll likely yield about the same amount of weed in both cases, but more harvests mean you’ll have fresh weed to smoke more often and have more opportunities to grow different strains. But more harvests also means more work in cleaning up the space between harvests, trimming, etc.

On average, it takes 3 to 5 months to go from seeds to smokable weed.

Note that low moisture content in the air can stunt growth and lead to longer vegging times, so you might need to raise humidity levels in your grow tent. Vegging time also increases every time you top your marijuana plants.

Curing weed eliminates the grassy smell and harsh flavor of dried buds. It also reduces the head rush aspect when smoking the buds, and makes them better at reducing anxiety, pain or feelings of depression.

Length Of Each Stage Of Cannabis Cultivation.

Why would you want this period to last any longer than it has to, though?

Most reputable online seed banks are located in Europe, but some have US offices, which cuts down on shipping times. Our article on the best places to buy marijuana seeds has everything you need to find the best seed bank.

If speed is the only thing that matters, you could switch to a 12/12 light cycle and begin flowering as soon as possible. Of course, this will result in much smaller plants and correspondingly smaller yields. We definitely do not recommend this, unless it is your goal to have small plants.

You should cure your buds for at least 2 weeks, but ideally a month or more. Drying generally takes a week to 10 days, though you could do it in 4 or 5 days.

The strain of marijuana you grow has the largest impact on how long it will take. If you choose a fast-growing strain, you can speed up the process considerably.

The following chart shows a breakdown of how long each stage takes in relation to the total time required to grow weed from nothing to the point where you can smoke it. This is based on the average time required for each stage. As you’ll see below, the actual times can vary greatly.

Time Required: 5 to 16 weeks (or more for select strains)

Our simple guide to growing marijuana covers everything you need to know.

If you are starting with clones, you don’t have to worry about germination, but you do need to get your clones to root, before they can start growing. This process usually takes 5 to 10 days. We have an entire article on getting your clones to root faster.

Even if you have the supplies, you may have to get everything set up, which can be done in a few hours, but may take a few days. If you are not sure what all you need, check out our article and checklist of the things you need to successfully grow marijuana indoors.

How much time it takes depends on a number of factors. That means it is not possible to give an exact time frame. It also means you can speed up the time it takes a bit.

How To Make Weed Grow Faster.

The amount of time it takes to grow cannabis can vary greatly, but there are things you can do to speed it up. Some, like shortening the vegging time, will have negative effects on yield, so you should always weigh the options carefully.

After harvesting your weed, you can’t smoke it right away. Well, you can, but we would not advise it. You should dry it at the very least, but ideally you want to cure it as well.

You also have to remember that your plants will approximately double in size from the beginning of the flowering stage to the end. This means you want to take them out of vegging when they are about half of the final desired size.

The reason this stage can last indefinitely when growing indoors is that you are the one who provides the signal for your plants that it is time to start flowering.

Let’s break the time it takes cannabis to grow down into the different stages, so you can get a better idea of how long each stage takes.