Growing marijuana starting from seeds can be a daunting task. Luckily we've put together the ultimate guide for growing weed from seeds! When it comes to how long it takes to grow cannabis, there really isn't a simple answer. Learn more about marijuana cultivation as we explore some of the general time-frames for different stages of the cannabis growing process. Good weed comes to those who wait. But just how many months do you need to grow cannabis, and when can you harvest your first yield?
Grow Weed Starting From Seed
“Don’t judge each day by the harvest you reap but by the seeds that you plant.”
Growing your own cannabis plant starting from seed is a remarkable journey. Understanding the biology of the plant is one thing, but comprehending how a little miracle bean can turn into a gigantic tree producing flowers that can affect your body and mind is nothing short of an evolutionary miracle. Or rather a co-evolutionary story of plant and human.
Start Growing Weed From Seed
Our favorite thing about growing your own weed starting from a seed , rather than a clone, is that you get to see the full life cycle and enjoy a plant that is unique, just like you. An entirely new genetic makeup will enter the world for the first time, and if you’re lucky, something remarkable might be born.
Raising a cannabis seedling , however, requires some patience, gentle hands, and a smidgen of luck. Thankfully pot seeds are remarkably vigorous because they are what’s called endosperm seeds , which means they have almost pre-formed cotyledon leaves before you even add water. Below is a brief guide on the techniques we have found yield the most success when starting seeds and raising your seedling to a healthy plant ready for transplanting. And, don’t forget, a Pot for Pot’s Complete Grow Kits take the guesswork out so you always wind up with a splendid harvest!
1) Germinating Your Cannabis Seed
To accelerate germination, soak your seed in a small container with lukewarm water and place it in a dark and warm place (like a kitchen cabinet) for 12-24 hours, but no longer. By drenching the seed, it absorbs the water thoroughly, activating the germination process on a physical and chemical level. Doing this helps to loosen the shell as it becomes a little softer making it easier for the embryo to crack it open. When your seed sinks to the bottom, it is ready to be planted, and sometimes the seed will pop out a small taproot. A seed can still be planted though if it does not sink or put out a taproot. When a seed pops a taproot (often called a tail), it becomes more vulnerable and it is better to plant it before this root emerges.
2) Planting Your Weed Seed
We see best results with seedling pellets that are made of a mix of compressed peat moss and coco husk. To expand, soak it in water for 10 to 15 minutes. Using warmer, lukewarm water, instead of cold water, will speed up the time the pellet takes to fully expand. Once your seedling pellet has absorbed enough water and has expanded to its maximum size, gently squeeze to remove excess water. The growing medium should be like a damp sponge that would not leave streaks on the table. Dig a small hole about 1/4 inch deep for your seed. Use a spoon to lift the seed out of its bath. If it has popped out a taproot be careful not to damage it. Gently place the seed into the hole and lightly cover it with dirt from the pellet. Now that you have started the germination process, your seedling will come above ground within two weeks. The older the seed, the longer it takes for it to germinate.
Want an easy-to-use starter kit for Cannabis seedlings? Check out our Seedling Starter Kit, perfect for nurturing your germinated seeds into viable, healthy plants.
3) Weed Seedling Sprouts
Perhaps the most exciting stage, your plant baby will come above ground in 1-2 weeks, with the average popping up in 5 to 7 days after planting. As your seedling comes above the soil, its shell might take a few days to fall off. It’s best to leave it alone, nature has the job covered. If it does not come above ground after about two weeks, the chance of success is dramatically reduced, and it’s best to try again. Even the best seeds have an 85% germination rate. When your seedling comes above ground, it is going to want to see a direct light source.
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4) Lighting for Your Cannabis Seedling
Marijuana seedlings require a medium amount of light — enough to get energy to grow, but not too much light that to get burned. Leaving your seedling in direct sunlight will cause the leaves to curl, while too little light will cause the seedling to stretch. If growing outside, seedlings want to see a direct light source to stop them stretching. If inside, a sunny windowsill with more than half a day of sunlight works wonders. Otherwise, 24 to 30 inches from a grow light is an excellent supplement. Your seedling should not stretch more than 6 inches at most.
5) Watering Your Cannabis Seedling
For cannabis plants young and old, it’s best to use bottled, distilled, or filtered water as these are without chlorine. If using tap water, let it sit for 48 to 96 hours before watering to dissipate any chlorine. Chlorine can also be eliminated by boiling for 20 minutes. Under normal conditions, after soaking your seedling pellet, it should contain all the moisture your plant needs before it comes above ground. As it grows, it will only need about a shot glass worth of water at most per week to keep the medium damp. Seedlings don’t drink a lot of water, which makes sense given their size. Your plant will do better in a growing medium which is damp but not soaking wet. Overwatering is just as deadly as drying out!
Damping off happens when the seedling is in too moist of an environment. The young plant’s immune system is not strong enough to ward off a fungus that results in the plant rotting from the bottom of the stem. When this happens, the plant will bend over and die if not treated. To help fight the infection, lightly spray a 0.5% solution of hydrogen peroxide around the affected area. However, the best option is to avoid this by not exposing your seedling to too much moisture.
6) First Cannabis Seedling Leaves & Hardening Off
The first set of leaves to come above ground are called the cotyledons . These little leaves are packed with energy and will grow to about 1/4 in in size before eventually falling off. Your second leaves to emerge will be single blades and will be serrated, looking like regular pot leaves.
They will become several inches in length. During their growth your first actual set of leaves will appear. These are typically three blades. Around this time is when your plant is “hardening off”. You will notice that the stem will start to develop a thicker skin and harden off. As the leaves of the plant get bigger, they can gradually handle more sunlight, so move it into more direct light– the more light the better!
7) Transplanting Cannabis Seedlings
About 10 days after germination, when the baby cannabis plant has hardened off, roots will start emerging from the bottom of your seedling pellet and the plant is ready to be transplanted into a bigger pot. Be very careful not to damage the roots during this stage. Any stress will slow its growth.
Dig a small hole in your bigger pot for the seedling, sprinkle some rooting booster in the bottom of the hole then carefully plant the whole seedling pellet holding your weed baby.
Now bury so the base of its stalk is level with the topsoil. Give it a watering to set the roots in the ground, then hold off watering until you pick up the pot and it feels light in weight.
Are you ready to transplant your seedlings? Shop our best selection of cannabis starter growing kits from small to large pots.
8. Separating the Girls from the Boys
At about 4-6 weeks into your plant’s growth , you’ll be able to determine the sex of the plant. You’ll want to separate and dispose of any male plants. This is an important step for growing marijuana because the female plants are more potent and valuable. You also don’t want male plants to compromise the growth of your female plants.
Why Do You Only Want Female Weed Plants?
Only female marijuana plants produce THC buds that are high in potency. You want to make sure your Cannabis plants are all female. If you have a male plant, it can fertilize the other female plants, and they will work to produce seeds instead of flowers and nugs.
It’s essential as a grower to know the difference between a female and a male plant so that you can remove the male plants before they contaminate your crop . Unfortunately, you have a 50/50 chance of getting a male plant when growing a plant from a seed from a nug.
There is a massive market for seeds that will only grow into female plants. But even these seeds are not a 100% guarantee you’re going to get a female plant. To ensure a good crop, you’ll want to germinate and plant many marijuana seeds and then separate the females from the males when the plants begin to show their sexuality.
How to Tell if a Weed Seed is Male or Female
As your plant matures sexually, it will develop between its nodes. Nodes are the area of the plant where the branches connect to the plant’s stalk. The distinguishing characteristics that will help you identify your plant’s gender:
- Male Plants : Small pollen sacs will cluster in the nodes.
- Female Plants : Stigmas will develop in the nodes. The stigmas can catch the pollen of male plants. Stigmas have hair-like veins that will extend from the sacs in the nodes.
- Hermaphrodite Plants : These plants have both the stigmas and pollen sacs in their nodes. These are female plants that develop both sex organs when exposed to a lot of stress.
Once you can identify the sex of your plants, you’ll want to remove the male or hermaphrodite plants because they can negatively affect the harvest of your female plants. That’s why it is crucial to germinate and grow several cannabis plants to this stage to ensure you get at least one healthy female plant.
9) Grow Weed Plant, Grow!
Suddenly, before your very eyes, the plant will transform. She will grow in height and branch out, putting off leaves and a network of branches. It is your job as the grower to meet her needs so that she can reach her full potential. With a good grow kit, this means as much light as possible and lightly watering only when she is thirsty.
This is considered your marijuana plant’s vegetive stage. The goal in this stage is to keep her healthy and allow the plant to grow as big and strong as possible so that she can hold many, many flowers.
Our complete grow kits include everything you need to go from seed to your very own supply of high grade medical cannabis.
How Long Does it Take to Grow Cannabis Plants?
T here are a lot of reasons to give growing your own cannabis a try. Regardless of whether you’d like to grow the herb for medicinal or recreational purposes, tending to your own cannabis plants can be rewarding for weed growing newbies and green thumbs alike, and may even be more affordable in the long run than purchasing marijuana at your local dispensary.
- Growing Marijuana: The Beginner’s Guide
- How to Grow Marijuana for Personal Use and Avoid Dispensaries
- How to Properly Distance Cannabis Plants in a Grow Room
- Closing the Yield Gap for Cannabis: A Meta-Analysis of Factors Determining Cannabis Yield
However, growing cannabis is not exactly like taking care of a potted plant, and one thing a houseplant certainly does not need is a deft hand to guide it through its grow cycles. After all, daisies will bloom if you can at least remember to give them some water and sun. Cannabis? Not so much.
To grow cannabis that can be consumed for its intended purpose, you’ve not only got to lead the plant through its many stages from germination to curing, but your plants require both attention and time. Which begs the logical question, how long does it take to grow marijuana plants? Let’s dig in.
How Long Does it Take to Grow Weed?
The very short answer is – that depends on whether you’re growing indoor, outdoor, greenhouse, coco, or hydroponic weed. Grow times for cannabis plants vary widely, but on average, expect about three-to-five months for indoor grows. However, there are many factors that could add or subtract from that range, including whether you choose to grow from a clone or a seedling, the target yield (how much consumable product) and the growing method you’ve chosen.
A very loose breakdown of a growing timeline could look like this:
Basic Cannabis Cultivation Timeline:
- Seed germination: 1-7 days
- Vegetative stage, when the plant is growing just stems and leaves: three weeks to eight weeks or more
- Flowering stage, when buds start to appear: five weeks to sixteen weeks or longer
- Harvesting, drying, and curing: two to four weeks
But the number one determinant of growing time depends on whether you’re growing sativa, indica, or hybrid cannabis strains. Let’s take a look at some average grow times for each.
Cultivation Time for Different Cannabis Plants
For those looking to grow cannabis more quickly or achieve higher yielding strains, indica is the way to go. With a shorter flowering period – about eight-to-twelve weeks – plus a generally higher end yield, growers often prefer them because they can be cultivated in more frequent cycles indoors, while outdoor growers can time several growing cycles before the weather turns cold.
Another benefit of growing indica seeds is that they tend to grow shorter and bushier than sativas, making them a better fit for indoor setups or growing in a backyard garden.
This cerebral and uplifting cannabis variety poses more challenges than growing indica. In addition to their longer ten-to-twelve week flowering period, plants grown from sativa seeds tend to produce a smaller yield (although this is certainly not true of all sativa strains).
Sativas can also grow to be very tall, up to 20 feet in an outdoor setting, which makes them difficult to conceal from neighbors in an outdoor grow setting. Even when confined inside, they may still grow long and lanky, a challenge for anyone trying to manage a small grow space.
A genetic mix of both indica and sativa strains, the growing time for hybrid marijuana strains may vary depending on which way the genetics lean.
Since hybrid seeds are a true blend of both sativa and indica, cultivators often prefer to grow them because of their higher output, generally faster growing time, and consumer appeal.
On average, hybrids tend to grow faster in the vegetative stage like a sativa, but may have a shorter flowering period like indica, about six-to-ten weeks.
Frequently Asked Questions about Cannabis Plant Growth
What is the fastest you can grow weed?
One seed company says they have a strain that can go from seed to harvest in 49 days. Before you buy seeds from any company, be sure to do your own research on quality and reputability, and make sure you’re getting a strain that suits your consumption habits and preferences.
Is there a way to speed up cannabis growth?
There are a couple of hacks that could speed up cannabis growth, including growing autoflowering hybrids, growing from clones instead of seeds, growing hydroponic weed, and changing up the stressors put on the plant (although this option is probably best left to more experienced growers).
Do you have any experience growing cannabis at home? How long did it take you from seed to harvest? Share your stories in the comments below.
Erin Hiatt is a New York City-based writer who has been covering the cannabis industry for more than six years. Her work – which has appeared in Hemp Connoisseur Magazine, PotGuide, Civilized, Vice, Freedom Leaf, MERRY JANE, Alternet, and CannaInvestor – covers a broad range of topics, including cannabis policy and law, CBD, hemp law and applications, science and technology, beauty, and psychedelics.
Erin’s work and industry insights have been featured on the podcasts The Let’s Go Eat Show, In the Know 420, and she has appeared as a featured panelist on the topic of hemp media. Erin has interviewed top industry experts such as Dr. Carl Hart, Ethan Nadelmann, Amanda Feilding, Mark A.R. Kleiman, Dr. James Fadiman, and culture icons Governor Jesse Ventura, and author Tom Robbins. You can follow her work on LinkedIn, WordPress, @erinhiatt on Twitter, and @erinisred on Instagram.
How long does it take to grow cannabis?
Good weed comes to those who wait. But just how many months do you need to grow cannabis indoors?
The average time for most indoor cannabis plants is roughly four months, but that could fluctuate depending on dozens of factors.
While it’s tough to say when your cannabis strain will mature, you could get a general timeline by reviewing marijuana’s primary stages of development. New growers should get comfortable with these phases to monitor their plant’s progress and schedule their time.
From germination to recreation: the average life cycle of cannabis plants
Traditionally, cultivators recognize four distinct phases in a cannabis plant’s life cycle before harvesting:
- germination: 1-14 days
- seedling: 2-3 weeks
- vegetation: 2-8 weeks
- flowering: 8-10 weeks
You could, however, eliminate the germination and seedling phases if you start with clones rather than seeds. In this overview, we’ll assume you’re beginning with a batch of healthy, feminized seeds.
It also assumes that the seed you have chosen is photoperiod sensitive, meaning that it’s flowering cycle is driven by how much light the plant is exposed to.
1. Germination phase: get your seeds going
You could plant cannabis seeds directly in soil, but most cultivators prefer coaxing out taproots before putting seeds in their growing medium.
Establishing these first roots gives cannabis seeds extra strength during the delicate seedling phase. It also allows growers to “weed out” any weak seeds beforehand rather than wondering whether they’d take root in soil.
The simplest way to jump-start germination is to wrap seeds in a slightly damp paper towel and cover them with a plate. You could also place seeds in a glass of purified water. The important thing is to keep these seeds far from light.
You also should take extra care to avoid contaminating seeds with your fingers. Some cannabis cultivators use tweezers to avoid any unintentional cross-contamination.
Usually, you’ll see white roots sticking out of your seeds in less than one week. There are some rare cases where it could take longer than two weeks, but you probably shouldn’t wait any longer than 14 days.
Monitor your seeds every day for signs of progress, and place them in starter pods once they show signs of development.
2. Seedling phase: growing baby buds
Seedlings should be ready to transplant into your main soil pot after two to three weeks (Shutterstock)
As your cannabis seedlings first reach for life, they will be incredibly fragile. During this early stage, you must use gentle lighting like a dimmed LED or a CFL bulb for 16 hours per day. 1
You should also only mist your cannabis seedlings with pH-corrected water.
Initially, seedlings will have tiny rounded leaves called cotyledons. However, as your plant grows, you should notice the true “cannabis” fan leaves emerge. Generally, people know they’ve transitioned from seedling to vegetation by the number of leaves on their plants.
When you see about four sets of about five fan leaves, your plant should be strong enough to transition to a larger pot. Typically, your seedlings should be ready to transplant into your main soil pot after two to three weeks.
3. Vegetation phase: time to flourish
The vegetation phase is all about growth. During this stage, your plants will rapidly reach upward and grow many stems and fan leaves. To help fuel this growth, vegetative plants need extra nitrogen in their feeding schedules. 2
Arguably, lighting is the most consequential element during vegetation. Since cannabis is a photoperiod plant, it will transition to flowering when you limit the daily amount of light. 3
Interestingly, you could transition from vegetative to flowering any time you want. There’s even a training technique called Sea of Green that takes advantage of this biological feature.
The downside of transitioning out of vegetation early is you’ll have fewer buds. By giving the cannabis plant plenty of time to grow, you’ll enjoy more bud sites, and thus a higher return. If you learn training techniques like bending or topping, you’ll increase your total yield even further.
To keep your strains in vegetation, you need to maintain a light schedule of at least 18 hours on. You could keep this going for as long as you want, but most strains are ready to switch after four to eight weeks. It all depends on how strong your flowers are growing, what strain you’re using, and what kind of yield you want.
4. Flowering phase: see the ‘fruits’ of your labor
In preparation to begin producing flowers, cannabis plants can double their size during early flowering (Shutterstock)
To transition from vegetation to flowering, you need to flip your light schedule from 18/6 to 12/12. The shortening of daylight hours mimics the natural seasonal change from summer to fall and triggers major changes in the plant’s hormones. 4
This causes the plant to shift its focus from growth and development of roots and shoots to the production of pistils as the female plant awaits pollination, which in nature would result in the eventual production of seeds before the plant dies during the winter.
Monitoring flowering plants is similar to vegetation, but you’ll need to transition to flowering nutrients and slightly lower your ambient temperature (~ mid-70s F). You also have to be extra vigilant for signs of mold or hermaphroditism during flowering.
You can determine the sex of a cannabis plant during flowering by looking at the nodes. Male plants have ball-shaped pollen sacs, while females have thin pistil-like strands. If you have a hermaphrodite, it will have both of these features, which means the pollen could disrupt bud production.
The length of the flowering stage largely depends on your strain’s average grow time. The only way to know when to harvest buds is to monitor their size and the color of their trichomes.
For most strains, it takes eight weeks to go through flowering, but it could easily last an additional two or three weeks with sativa strains.
It’s also important to consider that even though this stage is called flowering, that doesn’t mean the plants will solely concentrate on making buds. In preparation to begin producing flowers, plants can double their size during early flowering, so plan your grow space accordingly.
When’s a good time to harvest cannabis?
There’s no set time you should harvest buds from a flowering plant. Instead, you have to rely on your sense of sight to choose when’s a good time to clip your nugs.
Using a high-quality magnifying glass or a jeweler’s loupe, take a close look at the trichomes on each of your buds. Cultivators usually want most of these trichomes to have a milky-white, opaque appearance.
Clear trichomes are too young, and they will have minimal THC concentration. On the opposite extreme, orange-haired trichomes contain an oxidized form of THC known as CBN. 5 While some people enjoy CBN’s supposedly sedating effects, most prefer to clip their nugs when most trichomes are milk-white.
Want professional-quality cannabis? You’ll need patience!
Cultivators could use a few tricks to speed up the growing process, but most feminized seeds will take roughly four months to reach maturity. If you’re an impatient cultivator, you could opt for feminized autoflowering seeds, but remember these cultivars have a lower overall yield and often lower cannabinoid production.
For those not keen on the tradeoffs associated with autoflowers, consider starting with clones or focusing on indica strains to shave off significant time from your schedule. On average, indicas reach full-flowering weeks before sativa strains.
As a final tip, growers should research their preferred cannabis strains in online growing forums. Each hybrid has a unique growing pattern, and there’s a wealth of strain-specific information now available online. Knowing the estimated time for your cultivar is the best way to get an accurate read on how long it will take to grow cannabis.