how long for weed to grow

4 stages of marijuana plant growth

Cannabis plants go through a series of stages as they grow and mature, and those different growth stages call for different amounts of light, nutrients, and water.

It’s important to know these stages and how long each lasts to know what the plant needs and when. Knowing where your cannabis plants are in their life cycle will dictate when to prune, train, and trellis your plants, and when to harvest.

How long does it take to grow a marijuana plant?

Generally speaking, it takes anywhere from 10-32 weeks, or about 3-8 months, to grow a weed plant from seed. It’ll be quicker if you start with a clone or an autoflower seed.

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.

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.

When should you grow marijuana?

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.

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.

If you’re growing weed indoors, you can grow whenever you like. Keep in mind that the outside environment will affect your grow space—you may need to add heaters in the winter or fans and ACs in the summer. Other than that, you can start seeds whenever you like and flip them into flower whenever you like, depending on how big you want the plants.

Important dates for growing marijuana outdoors

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

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 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.

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!

Notes on marijuana growth phases

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.

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.

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.

What are a weed plant’s growth stages?

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

  • Germination (3-10 days)
  • Seedling (2-3 weeks)
  • Vegetative (3-16 weeks)
  • Flowering (8-11 weeks)

Seed germination

Seed germination length: 3-10 days

Marijuana light cycle: 16 hours a day

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.

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.

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.

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.

Seedling stage

Seedling stage length: 2-3 weeks

Marijuana light cycle: 16 hours a day

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.

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.

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.

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.

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.

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

Vegetative stage

Vegetative stage length: 3-16 weeks

Marijuana light cycle: indoor—16 hours a day; outdoor—at least 8 hours of direct sunlight (“full sun”), plus several hours indirect sunlight

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.

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.

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

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.

Flowering stage

Flowering stage length: 8-11 weeks

Marijuana light cycle: 12 hours a day

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.

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.

Within the flowering stage, there are three subphases:

  • Flower initiation (week 1-3): The plant will continue to grow and females will develop pre-flowers—pistils, or white hairs, will grow out, which are the beginnings of buds.
  • Mid-flowering (week 4-5): The plant itself will stop growing and buds will start fattening up.
  • Late flowering/ripening (week 6 and on): Trichome density will increase and plants will get very sticky; keep an eye on the color of the pistils to tell when to harvest.

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

  • Don’t prune when plants are flowering stage, as it can upset their hormones
  • Plants should be trellised so buds will be supported as they develop
  • Consider giving plants bloom (phosphorus) nutrients

When do buds grow the most?

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.

Once buds have reached full maturation, it’s time to harvest your marijuana.

Pat Goggins and Trevor Hennings contributed to this article.

Knowing where your cannabis plants are in their life cycle will dictate when to prune, train, and trellis your plants, and when to harvest. Learn more about marijuana growth stages today.

How long does it take to grow weed?

Many new growers ask us: how long does it take to grow weed? A solid question as most want to plan their culture. If you are wondering how long you have to wait for a weed plant to grow, the first thing you need to understand is that the art of cultivating marijuana cannot be rushed, quite the contrary. After all, Rome wasn’t built in a day and neither was a fine crop of delicious weed plants. The correct development of your plant, in time and architecture, will be what will mark the difference between a solid, firm and productive plant, and a “cluster of branches” with little foliage and low production.

In this article, we will discuss the typical development time of the plant, as well as the different phases it will go through before it is ready to harvest. Here are some of the questions that often arise on the subject:

  • How long does cannabis take to germinate or flower?
  • How can I get the plant to flower as soon as possible?
  • Is it possible to accelerate growth?
  • What is the fastest growing and most productive plant?

How long does it take to grow a weed plant?

These frequently recurring questions make us understand that more than ever, time is money. However, you should understand that the purpose of this article is not to respond subjectively to these questions, but rather to give you a thorough overview of the topic so that you know the courses of action to follow to determine the development time of a cannabis plant.

Let’s begin this explanation by differentiating the different stages of plant development:


The germination phase is defined as the length of time it takes for the seed to develop to transform into a seedling.

If you use cuttings, this germination time will be identified as the cloning and rooting time.

The methods of germinating cannabis seeds are different. The most common is to use a wet kitchen towel as a base for the seed. However, many growers use other methods, such as damp cotton, or even directly in the soil, in a Jiffy bag or in water.

Some growers also use germination boosters, which promote the seed’s initial metabolism and soften the seed pod, greatly reducing germination time.

For the other cases, the time is relative. It will depend not only on the type of variety but also on the quality of the seed. Other determining factors will be the age of the seed, its fertility, and the way it has been stored.

The time it takes for the seedling to emerge usually varies between one to five days, although it is not unusual to see seeds take 5 to 15 days to germinate. This will depend on water, humidity, oxygenation, and especially the temperature which must be between 21 ° and 24 ° C during this phase.


Also called the vegetative phase, it is crucial in the development of the plant, except that it is probably the most important phase.

After having obtained your seedling and carefully carrying out its transplant (in a Jiffy or directly in the pot), the growth phase will commence. As its name indicates, it is at this point that the plant will achieve a good part of its size, as well as the architecture necessary to start the next phase as strongly as possible.

As we already know, the photoperiod at this phase will be more important than for the others. In general, we recommended applying 18 hours of light for 6 hours of complete darkness each day. A correct balance between light and dark will be the key to perfect development. Light will be important for photosynthesis, but absolute darkness also plays a key role, because it is during this period that is realized.

This period will vary according to the variety of seed you plant, the variety and/or the crop you have chosen to use. This means that auto-flowering plants will grow more quickly than feminized varieties, and indoor crops will, in general, grow more rapidly than outdoor ones. Similarly, using a high-powered light source will help plants to grow faster than using less powerful lamps.

It is impossible to exactly quantify the length of the growth phase, but the same is true for the other phases, because of plant, environmental, and external factors (such as fertilizers and the dexterity of the cultivator) which can have a considerable impact. In general, indoors, you will count 3-4 weeks (21-25 days) for automatic varieties and around 6 to 8 weeks for feminized strains.

Although regular and feminized seasonal cultivated outdoors often take 8-9 weeks to complete their growth stage, indoors it is possible to falsify climatic and ambient conditions to shorten growth.

Once the right conditions are in place, when you see your plant reach an adequate size and start to open its initial inflorescences, it will be time to switch the photoperiod to commence the flowering cycle.


Flowering is the last period of development of the cannabis plant. Its start will not depend solely on the growth time you give the plant, but also whether or not it has the right characteristics to support the precious buds that it will develop during this phase.

Indeed, you may come across plants that will remain weak, small and without inflorescences even after a month since germination. In this case, you will still need to stay in the growth phase to allow for more solid training.

The automatic varieties will start flowering almost autonomously, which will require you to change the photoperiod when they decide to so close daily observation is necessary. Seasonal seeds, indoors, will depend on the grower’s goodwill. You will need to alter the photoperiod to 12 hours of light and 12 hours of darkness per day, to use the light stress to push the plant towards the flowering phase.

If the time of a growing plant is relative, this is all the more the case in flowering. Here, there are no other rules than those listed by the seed banks for their variety, that said, in the majority of cases, they will be only for information.

What matters when deciding when to finish flowering, and therefore when to clean the roots and cut the plant, is to be able to see the complete bud development. Even if the time indicated by the seed bank will give you a rough idea of ​​the right time to cut, the main thing is to be able to see that the buds are growing until they cover most of the pistils.

Once your weed plants have fully ripened, harvest time will be revealed by the ripening and progressive oxidation of the trichomes and pistils, which acquire a characteristic amber/honey colour.

Indoors, auto-flowers generally complete their development in about 8 weeks. Feminized strains will take longer depending on the growth you have produced, with an average of 10-12 weeks.

Drying and curing

This phase cannot be considered in the strict sense as a phase of the cannabis plant, but as it is a process which takes time and which is determining to obtain a quality product in terms of flavour, odour, effect and power, it is normal to consider it as a separate phase, with its own characteristics.

It is necessary to make a distinction between drying and curing weed. Drying is the first treatment to be carried out once you have harvested.

Drying will consist of placing your recently cut and manicured buds, in a dry, dark, and cool place, on a drying mesh (remember to thoroughly clean the roots with abundant watering before cutting). Every day you will need to change the position of the buds on the mesh to avoid distorting them.

This process can take 2 to 4 weeks, depending on the location and the conditions of maintenance. The signal that will tell you a bud to dry ideally, will come when you try to bend the stem where the buds are. If you hear a crackle without the stem breaking, your flowers will be ready for curing.

This step aims to put every bud in an airtight container and let them sit with periodic ventilation. Curing can be carried out in various containers, in plastic, glass or drink. Wood is faster, and glass is more practical because it emits no toxic substances or odours.

The container in which you place your harvest should be stored in a dark, cool and dry place. The only thing you will need to do is open the container each day for several minutes so that the little remaining moisture gradually evaporates.

This process generally takes between 2 and 6 weeks. The key moment in ripening will come when the bud creaks by taking it lightly. The idea is to make the intense green go away and no longer emit this vegetable odour, which comes from the chlorophyll still contained in the plant.


According to these estimates, we see to what extent cannabis is slow to develop fully: around 3 months for autoflower varieties, and 4-6 months for feminized according to the type of culture used and the care provided. Besides, you must take into account the drying and refining which can last from 1 to 2 months approximately.

We specify that it depends on the care given to the plant, as well as the variety you choose, the times dedicated to each phase will be more or less long, which therefore influences the time of complete development. Feminized varieties will take longer than automatic ones, for example. In general, weed plants grow much faster in indoor crops, but keep in mind that it is mainly the patience of the cultivator that is fundamental to get the best results.

Growing weed plants is a time-consuming process, but one which can be a lot of fun and that we think you will find very rewarding!

Wondering how long it takes to grow a weed plant indoors or outdoors? Check this blog and find out!