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How long for a cannabis seed to bloom

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 cycles 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 to harvest. 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.

When growing outdoors, you’re at the whim of the seasons and will have to wait until the sun starts to go down in the fall for plants to flower, and then to harvest.

However, one way outdoor growers can control the flowering cycle is by using light deprivation techniques.

How long can a marijuana plant live?

Weed plants are annuals, meaning they grow and live for one season and then die. Wild cannabis plants grow seeds and drop them when they die, which will grow into new plants the following year.

When harvesting, plants are cut down and die in order to get their buds. New seeds need to be planted in order to grow more plants.

If left unharvested, weed plants will eventually wither and rot within a few months after the peak flowering phase.

When should you grow marijuana?

If you’re growing outdoors in the Northern Hemisphere, growers usually get their seeds between February and April and start germinating seeds by the end of April.

Many start growing seedlings inside in a more controlled environment because seedlings are more delicate, and then put the seedlings in the ground outside once they’re a little bigger and the weather is warmer.

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.

Harvesting 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; growers in the Pacific Northwest will have to pull down their crops earlier than those in Northern California because of cold weather.

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

Many growers begin germinating seeds as early as February and March in order to have big plants come harvest time, but the Spring Equinox is a good reminder that it’s time to kick off the outdoor growing process and start germinating your seeds if you haven’t already.

Many farmers wait until after Mother’s Day in May to put their plants outside. Just make sure all of your plants are outside by the Summer Solstice at the latest.

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 the Fall Equinox is about when to start harvesting. It’ll depends on your climate and the year—it could happen a little before or after.

Everything should be cleaned up, dried, and curing by Thanksgiving, and in some places, even by Halloween.

As winter approaches, it’s prime 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 next year.

Take meticulous notes on when and how you perform each step, noting:

  • Weather
  • How much water you give plants, and at what intervals
  • Nutrient amounts
  • When you top and prune

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)

Cannabis seed germination

Seed germination length: 3-10 days

Marijuana light cycle: 18 hours a day indoors; full, direct sun 6 hours a day outdoors

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 so the plant can grow 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 in cannabis plants

Seedling stage length: 2-3 weeks

Marijuana light cycle: 18 hours a day indoors; full, direct sun 6 hours a day outdoors

When your marijuana plant becomes a seedling, you’ll notice it developing 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, or “fingers” (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 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 in cannabis plants

Vegetative stage length: 3-16 weeks

Marijuana light cycle: 18 hours a day indoors; full, direct sun 6 hours a day outdoors

The vegetative stage of cannabis is where the plant’s growth truly takes off, and it typically lasts 3-16 weeks. 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 high 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.

Cannabis plant flowering stage

Flowering stage length: 8-11 weeks

Marijuana light cycle: 12 hours a day indoors; full, direct sun 6 hours a day outdoors

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 18 to 12 hours a day.

There are three subphases of the flowering stage:

  • 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, as it can upset their hormones
  • Plants should be trellised or scrogged so buds will be supported as they develop and air can flow through plants
  • Consider giving plants bloom or 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. How long it takes to harvest buds depends on many factors, including harvesting methods and how many plants you harvest.

The Life cycle of Cannabis: From seed to harvest

Cannabis passes through a series of stages in its life. The most important of these are the germination, seedling, growth and flowering stages. Each stage brings its own challenges. Novice growers need to be aware of these, to be sure of giving their plants the attention and care that they deserve.

Plants are living beings. They are at the base of the evolutionary tree, they heal our bodies and souls, they delight our senses. I think all our readers know by now which is our favourite plant: Cannabis sativa L. – a fantastic crop and medicinal plant, and one of the oldest plant genera in the world.

No matter why cannabis is being cultivated, to see with your own eyes how a small seed grows into a bulky plant, which then starts flowering, is a moving experience every time.

Cannabis is an annual plant, so its entire lifecycle takes place within a single year, with most varieties reaching the end of their life after between four and ten months. In general terms, the following four stages of life can be distinguished:

  • Germination stage
  • Seedling stage
  • Growth or vegetation stage
  • Flowering stage

A quick glance is usually enough to determine the current stage. Over time, it is not just the appearance of the plant that changes, its needs also change. Different stages require different quantities of light, water and nutrients. Furthermore, if you want to determine the sex of the plant or prune it, it is useful to know which stage the plant has currently reached.

1 – Germination stage (1 to 2 weeks)

All forms of life start from a seed of some kind. High-quality seed is the single most important factor for successful cultivation. Cannabis seeds should be hard, dry and brownish in colour. There are a number of different ways of getting the seeds to germinate. The easiest is the paper towel method.

In the germination process, the germ in the seed breaks through its shell and forms a root, which is known as the taproot. Germination takes anything from 24 hours to 7 days. Generally cannabis varieties with a high proportion of Indica germinate faster than pure Sativas.

The germinated seed can now be placed carefully into the growing medium. The plant will start to grow and force its way upwards.

While the first two cotyledons (seed leaves) are being formed, the plant shrugs off the protective seed husk. That signifies the end of the germination stage.

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2 – Seedling stage (2 to 4 weeks)

Particular care is necessary at this stage in the lifecycle. Seedlings are susceptible to illnesses and mould. Many novices get carried away with watering and give the seedlings too much fertiliser. Even if you plan to grow outdoors, it may be useful to give the plants a healthy start indoors, assuming that a location is available with adequate light (e.g. a windowsill). The plants need as much light as possible at this stage.

How long the seedling stage lasts depends on the variety and on the environmental conditions. The main focus of the plant is on developing a root system. This forms the foundation for its later growth.

Meanwhile the plant will grow its first “real” leaves with the characteristic marijuana shape.

The leaflets are long and jagged. Initially a leaf has just one leaflet, although a mature cannabis plant will have five to seven leaflets per leaf.

Once the plant produces the full count of leaflets for each new leaf, the seedling stage is over.

3 – Growth stage or vegetation stage (2 to 8 weeks)

Now the plant starts its main growing phase. Provided it receives enough light, it can grow up to two inches (5 cm) in a single day. It is obvious that the plant needs to be repotted if it is still growing in a small pot.

Leafy plants like a healthy soil that is rich in nutrients. The production of chlorophyll and proteins depends on a supply of nitrogen. It is worth investing in the right kinds of fertiliser or even producing them yourself.

As it grows, the plant also needs more water. Young plants are best watered close to their stem, but later on water should be distributed more widely so that the tips of the roots can absorb water more efficiently.

Have you ever heard of topping, super-cropping or lollipopping? Using these techniques you can train cannabis or manipulate the shape of the plant. Growers use them to develop stronger plants with more buds. Opinions vary, however, on whether these techniques actually deliver results. They are only necessary for special cultivation methods such as the Screen of Green (SCROG).

How long the growth phase lasts is not a simple question to answer. Autoflowering cannabis varieties move automatically on to the flowering stage within 2 or 3 weeks. Regular or feminised varieties only start flowering once the days become shorter (outdoor cultivation) or the grower reduces the lighting period to 12 hours (indoor cultivation).

How to germinate cannabis seeds

So, you’ve decided to grow your own cannabis plants. You purchased a pack of seeds, assembled cultivation materials, cleared a space in your garden, and are ready to grow your first cannabis crop . With everything in hand, it’s time to begin the very first step of cannabis cultivation : germinating seeds.

What is germination?

Germination is the first stage of the cannabis growth cycle : the process that brings a cannabis seed out of its hibernation period and starts the cannabis growth process. After all, seeds in a bag don’t spontaneously start developing roots. Also known as “popping” seeds, seed germination begins when a seed receives environmental cues letting it know the setting is perfect to start growth.

Germination is the process that brings a cannabis seed out of its hibernation period and starts the cannabis growth process. Photo by: Gina Coleman/Weedmaps

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When a seed enters an environment with enough moisture, it will increase in size and slowly break out of its shell. A seedling or germ forms from which roots will emerge, helping the baby plant absorb nutrients from the soil. Seeds naturally develop roots facing down and stems stretching upward, allowing the young cannabis plant to simultaneously feed off light and earth.

It’s essential to acquire high-quality cannabis seeds for germination, as these will go on to become high-quality cannabis plants. Seeds that are fresh-feeling or too green indicate that they haven’t reached full maturity, while pale-green, white, or very dark cannabis seeds may have trouble sprouting. However, it’s tricky to know the outcome of a popped seed, so trying may be worthwhile. If you’re not ready to pop your seeds yet, store them in a dark, cool place until it’s time for germination.

Preparing to germinate cannabis seeds

Germination itself is a crucial aspect of cannabis cultivation. The seed germination process is the foundation of every marijuana plant, and steps can be taken to boost successful popping. For example, some cultivators improve germination attempts by soaking seeds in 1% hydrogen peroxide or a compost tea for 12 hours beforehand to kill any dangerous pests.

The environment in which seeds germinate also plays a role in the outcome. While there are several different germination methods, each requires proper moisture, minimal handling, and warm springtime temperatures between 68-72 degrees Fahrenheit.

How to germinate cannabis seeds

The best germination method depends on the cultivator’s choice. Here are some of the most common ways to pop your cannabis seeds.

How to germinate seeds in soil

Soil is an easy, more natural method with which to germinate your cannabis seeds. The soil protects the fragile roots from any interference, and soil is, after all, where a cannabis plant would grow in the wild.

Soil is an easy, more natural method with which to germinate your cannabis seeds because the soil protects the fragile roots from any interference. Photo by: Gina Coleman/Weedmaps

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First, make sure you use the correct type of soil, either gently fertilized potting soil or a seed starter with a pH level of approximately six (6). The soil contains the right acidity and enough nutrients to strengthen your young cannabis plants for the first two weeks. Be careful not to add more nutrients, or you risk overfeeding and killing your seeds.

Place the soil in a small pot and use your finger or a pencil to push a small hole in the dirt, a bit more than half an inch deep. Insert the seed into the hole and bury it with soil. From this point on, don’t touch your seed. The young plant is fragile and knows how to position itself in the soil bed.

Gently water the soil with a spray bottle and situate your pots under a fluorescent lamp. Keep seeds away from the windowsill, as the temperature is too volatile for germination. In general, you’ll want to keep the temperature in the range of 70 to 80 degrees Fahrenheit.

Monitor your soil every day and keep it moist. Within four to seven days, you should see tiny stems sprouting from the soil.

When the seedling stems reach two to four inches in height, it’s time to transplant your cannabis into larger pots with more room for roots to spread down and out. After you’ve done this, you’ve successfully germinated your cannabis seeds into proper, young plants.

How to germinate seeds in water

You can also germinate your seeds by placing them in water. It’s slightly faster than the soil method, but you need to adjust your environmental factors accordingly. Remember, successfully germinating seeds requires a perfect balance of ideal growing conditions. When germinating in water, seeds need only 24-48 hours to pop their stems, though cultivators can keep them soaking for up to a week as needed. Water germination is faster because the seed gets all the moisture it needs immediately, and the shell softens and cracks more easily after soaking.

To employ water germination, fill a glass with tap water and let it sit until it reaches room temperature or around 65 degrees Fahrenheit. Add two to three plant seeds per cup and allow them to sit, watching for any changes. Change the water to fresh tap water every two days, making sure it stays at room temperature.

The seeds should start sprouting in about two days, though older seeds can take up to a week to sprout. You can remove them from the water and place them in the soil at any point once they’ve sprouted. Once the roots are about five millimeters long, they need to be planted.

The downside of water germination is that once they’ve popped, you’ll need to maneuver them into their growing medium manually. This is a delicate process, as germinating seeds are extra fragile, and any harm risks the development of your plants. Make sure to place the seed roots down in the soil when you transfer to a pot.

How to germinate seeds using paper towels

The paper towel method is also a common way cultivators pop their seeds. Some even use this method with cotton pads instead of paper towels, but the necessary steps are the same.

To germinate seeds this way, lay one paper towel on top of a countertop, place a few seeds, and cover them with a second paper towel.

Lay one paper towel on top of a countertop, place a few seeds, and cover them with a second paper towel. Photo by: Gina Coleman/Weedmaps

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Use a spray bottle to moisten the paper towels and then store the cushioned seeds between two plates, under a face-down bowl, or gently place them in a plastic bag. Maintain a temperature of about 72 degrees Fahrenheit, keeping the paper towel wrapped seeds in the dark and away from a windowsill. In two to five days, the seeds will pop inside the paper towel sandwich and emit tiny roots, ready to plant when they reach about five millimeters in length.

Use a spray bottle to moisten the paper towels and then store the cushioned seeds between two plates, under a face-down bowl, or gently place them in a plastic bag. Photo by: Gina Coleman/Weedmaps

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The paper towel method also has its risk, as the fragile seedlings can be damaged during the potting process. The tiny roots can also get tangled in the paper towels, so make sure to move the seeds to potting soil before roots grow too long. Use your hands or tweezers to gently remove each seed from the paper towels and place them in a prepared growing medium.

How do you germinate seeds indoors?

Whether you’re planning an indoor cultivation or outdoor grow, it’s best to germinate your seeds indoors. It’s easier to maintain proper temperature, light exposure, and moisture inside, and you can protect your seeds from the elements. Indoor germination, whether using soil or paper towels, will ensure your cannabis seeds have the best chance for survival.

To germinate seeds indoors, use any of the methods described above. Within a few days, you’ll have popped seeds ready to transfer to a growing medium.

Do you need to germinate seeds before planting?

While many plants can be germinated in the ground, cannabis seeds are fragile enough that you should germinate them before planting.

Once your seeds have sprouted roots, they should be planted in soil, a soil-less medium, or in your hydroponic setup. Make sure not touch the root, caring for and navigating the seedling so that the roots face downward. Plant the seed about one inch deep in your growing medium, cover lightly, and allow for about a week for the seed to emerge from the soil. If the seed hasn’t poked through by day ten, it likely didn’t survive.