how big weed plants grow

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.

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.

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.

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.

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.

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.

Within the flowering stage, there are three subphases:

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

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.

How long does it take to grow a marijuana plant?

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.

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.

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.

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 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.

When should you grow marijuana?

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.

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

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.

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.

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

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.

Weed typically likes warm, temperate climates—think of Northern California’s Emerald Triangle region—but certain strains thrive in different temperatures. Traditionally, indicas like cold, dry climates and sativas like warm, humid climates.

How much light a plant receives is highly variable. When growing outside, it all depends on where a plant is located to receive the most light throughout the entire season. Weed plants like full sun—at least six hours of direct sunlight every day. If a plant is in the shade or gets shaded as the light changes throughout the season, it can affect yields.

When growing indoors, you’re often limited by space—a plant can’t get as big in a grow tent as in a big, open basement. You’re also limited by how powerful your grow light is. For example, Leafly editor David Downs harvested 150g from one indoor plant with one 200W Black Dog LED light. The company said that light maxes out around a half-pound of buds, or 224g.

Check out guidelines on how big of a container you need for different sized plants here.

We’ll go through those factors and talk a little bit about the harvest process to estimate how much weed you can get from one plant.

Light.

Also, these estimates are for healthy plants. If a plant becomes nutrient-deficient, gets bugs or mold, or doesn’t receive enough light, expect a lot less.

For example, Lemon Skunk is famously a tall, lanky strain, so you’re likely to get high yields from it. Blue Dream and Chemdog are also known for their high yields.

Additionally, if growing in containers, the size of the container, or the amount of soil the plant’s roots have, will affect the size of a plant. Growing in too small of a pot can stunt a plant’s growth.

Note that these are estimates . When growing outdoors, plants can usually get massive because they aren’t restricted to space—it’s not uncommon to get closer to a pound a plant or more.

Aside from its candy-like flavor, Runtz gets its name because its buds grow small, like the runt of the litter. It might be a low-yielder, but you’ll usually get high-quality buds.

Be sure to prune your plants to remove dead leaves and buds, and branches that won’t turn into sizable buds. Clearing out plant matter will allow the quality buds to get more light.

Sudden extreme changes in temperature can affect a plant’s growth and yields, such as a sudden cold snap, which can slow a plant’s growth, or a heatwave, which can dry out a plant.

However big your plant gets, you’ll likely have more flower than you know what to do with. Many people will save a certain amount of flower for smoking, and make edibles, concentrates, and other weed products with the rest of their harvest.

Some regions get rain early in the fall, so you’ll want to grow plants that are ready to harvest by the beginning of October. In tropical climates, you can practically grow weed outdoors all year round.

As states legalize weed and the plant becomes more accepted, more people are trying out their green thumbs by growing their own weed at home. Most states with legal weed allow one person to grow six plants at their residence and an entire household to grow 12 plants. Some allow less, and some allow more.

Growth duration.

How long you allow a plant to grow, or the length of time from seed germination to harvest, is one of the most significant factors determining weed yield. If you start growing seeds in March rather than May, those plants will have two extra months to get big.

The amount of dried buds you harvest from a weed plant is called its yield, just like any crop, such as corn, wheat, fruit, etc. Ideally, when growing weed, you want high yields and high-quality buds. Getting both takes a little practice.

So if you weigh a freshly cut plant at three pounds, don’t get too excited—you’ll likely get ¾ lb. of finished buds (which is still a lot of weed).

Some major factors that contribute to a weed plant’s yield include:

Indoors, it depends on how powerful your light is. A small 200W LED is great for a small grow tent, but you’ll need something bigger for a bigger space, which also means a more expensive light.

Many factors affect how big a plant gets, but generally speaking, if you are growing a healthy plant, you can expect these yields from one weed plant:

Different soils have different nutrient levels and some nutrients can promote plant growth. You can also add nutrients to soil or water to help plants grow big and strong.

How long will one plant’s worth of bud last you?

Certain weed strains grow big or tall or are high-yielders simply because of their genetics. Traditionally, indicas grow short and stout, and sativas grow tall and lanky. That’s not always true across the board, but it is a good rule of thumb.

Consider how much weed you smoke in a day, week, or month. For reference, a gram is about two medium joints or 3-4 bowls. Do you smoke a gram a day or a week? Two grams a day or a week?

Using the above yield estimate of ¼ lb., or 112 grams, for one medium-to-large-sized indoor plant, if you smoke one gram a day, that one plant would last you 112 days, or just under four months! Two grams a day would last you just under two months, and half a gram a day—or an eighth a week—would last you eight months.

When growing indoors, growth duration is determined by how much space you have to work with. If you have a spacious basement or shed, you can let plants grow for months and get as big as you want before forcing them to flower. If space is tight, like in a grow tent or other small areas, you may only be able to let your plants get a few feet tall.

This will help give you a sense of how many plants you should grow. If you’re growing indoors, you can grow one plant at a time, harvest it, and start another, keeping a continuous cycle of growing.

(To see how many plants your state allows you to grow at home, check out this table ) .

When growing outdoors, the local climate is the main determining factor of when you can put seeds in the ground. Some regions are too cold to put plants outside until May, but you can start growing plants indoors with the right setup.

A big plant doesn’t necessarily mean big yields, as buds can be thin and wispy. A medium-sized plant with quality, dense nugs could yield more than a six-foot tree. Also, if growing multiple plants, they can grow over each other and shade one other out, reducing yields. Make sure to give plants plenty of space.

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

But that's a huge range, right?

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

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

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How tall will my marijuana plants get?

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.

How long will it take?

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

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

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.

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

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.

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

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

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

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

Learn from the best!

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).

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.

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

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.

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

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!

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.

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

How tall will it grow?

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