Categories
BLOG

how tall do weed plants 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 tall will my plant grow? And how long will it take?

Question: How tall should I expect my marijuana plants to get? And how long does it take until harvest?

How long will it take?

How tall will it grow?

Get the answers below!

These are very common questions for new growers, so let me give you the straight answers…

How long will my marijuana plant take to grow? How long from seed to harvest?

It will be 8 weeks – 6+ Months before your plants are ready to harvest.

But that’s a huge range, right?

The truth is, the time to harvest depends on your growing method, whether you grow inside or outside, your strain, and your desired yields…

Growing Method – soil tends to be the slowest growing medium, and hydro tends to create the fastest growth

Inside or Outside – In general, outdoor plants need longer to harvest than indoor plants. Outdoors, you plant in the spring, and harvest in late fall, taking 5-6 months or more. Indoors you have more control over the plant and can choose how long you want your plants to grow before harvest, and can get to harvest in just a few months. Indoors you can also start growing at any time (you don’t have to wait until Spring to start growing).

Strain – Some strains tend to have shorter lives, and others need longer before they’re ready to harvest. For example, you can choose to grow an auto-flowering strain to get to harvest in as short as 8 weeks. But many strains which originated near the equator can take months and months before their buds are ready to harvest, even when growing indoors. So strain is important when it comes to time-to-harvest.

Desired Yields – If you want bigger yields, you need a bigger plant, and that takes more time to grow than a small one.

Discover Exactly How Long It Takes Before You Get to Harvest

How tall will my marijuana plants get?

Plants can be grown shorter than your knees, or taller than your house.

Basically you (the grower) are in complete control of how tall your cannabis plants grow.

This is especially true for indoor growers, where you are in charge of nearly everything. When growing outdoors, you still have a bit of control over plant height, but you are also at the mercy of the sun and the elements.

Some strains tend to grow tall and thin, while others tend to grow short and squat, but you can force your plant to grow differently when growing cannabis indoors. In fact, you have many options to control the exact shape and size of your plant.

To learn about all the tools and techniques you have available to control the height and shape of your plant, take a look at our Plant Training & Height Control guide!

Short plant in a small space – this plant is only about two feet tall thanks to training with a screen, yet still producing lots of bud! You don’t need a huge space to get a good harvest when you use plant training.

These cannabis plants were also trained to stay short, this time using LST – they were under two feet tall at harvest and produced more than 6 ounces of bud under a small grow light!

These plants were trained using manifolding. They were about 5 feet tall at harvest, and produced more than a pound of bud!

You can achieve almost any size or shape when growing indoors as long as you use plant training. But if a cannabis plant is left to grow outside with tons of sun and without any plant training, the sky is the limit for how big they can get!

Although it isn’t the be-all end-all when it comes to size, strain is still definitely something to keep in mind when it comes to height. Although you can control the exact height and shape of your plant no matter what the strain with plant training, different strains grow differently and you want a strain that makes it easier to get the results you want. When growing with bagseed (seeds that you find in your buds) you often don’t know what to expect until the plant actually starts growing.

For example, some strains (known as “indica” strains tend to stay short, while “sativa” strains tend to grow tall). Just to give you an idea of the difference, these plants were grown in the exact same setup.

To fight these natural tendencies and force these plants to be the same height, the grower would have needed to use different techniques and training strategies. If the grower had wanted to make the right plant shorter, the plant would have needed more Low Stress Training and Supercropping.

For the left plant to grow taller, the grower would have needed to give the plant more time, since indicas tend to stay short. So even though you can force plants to grow into any size and shape, it’s often easier to start with a strain that naturally grows the way you want. That way your plant is working with you instead of against you. Learn how to find the right strain for your needs.

Learn more about how to get your plants to grow the size and height you want!

FOR SERIOUS GROWERS ONLY

You’ve told me you’re looking for a complete guide to growing marijuana that covers everything, from beginner to ultra-advanced.

And super cropping is just one technique to getting seriously killer harvests. If you want to learn ALL the secrets…

Learn from the best!

Total care explained step-by-step… indoors… outdoors…

Monster cropping… advanced growth control… bud production secrets… and much, much more…

Over 700 pages of pictures, tutorials and advanced insider tips!

Get Instant Access to It All Right Here: GrowWeedEasy.com/growing-elite-marijuana

I thought I already knew it all, but after I went through this grow bible, I discovered that there were still lots of easy ways I could increase my yields and grow even more potent buds! I find myself going back to it again and again for new ideas.

About Nebula Haze

In response to the need for more tutorials aimed at new growers, Nebula co-founded GrowWeedEasy.com in 2010 with fellow grower Sirius Fourside.

Since then, Nebula has published hundreds of growing articles in print and online, and continues to dedicate herself to serving the medical marijuana growing community.

“My mission is to show other medical marijuana patients how easy it can be to grow weed out of your closet.”

[Answer inside!] These are very common questions for new growers, so let me give you the straight answers…