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 in a marijuana grow tent.
Generally speaking, it takes anywhere from 14-32 weeks, or about 4-8 months, to grow a weed plant.
The biggest variability in how long a marijuana plant takes to grow will happen in the vegetative cycle—if you’re growing indoors, you can force it to flower after only a few weeks when it is small, or after several weeks when it is big. If you’re growing outdoors, you’re at the whim of the seasons and will have to wait until fall to harvest. The plant will develop buds in the last 8-11 weeks.
The life cycle of cannabis can be broken down into four primary stages from seed to harvest:
Germination (5-10 days)
Seedling (2-3 weeks)
Vegetative (3-16 weeks)
Flowering (8-11 weeks)
1. Germinating Seeds
To effectively germinate, you must ensure that seeds are mature enough. If your seeds are immature they will likely not germinate.
If your seeds have reached maturity they will appear shiny & light to dark brown & will be dry & hard to the touch.
If your seeds are underdeveloped they will feel soft & appear white or green.
To germinate, keep your seed in a wet, dark place. Some growers may keep it in a cup of water or wrapped in a wet paper towel & set inside of a cabinet.
Exposing seeds to light & moisture stimulates hormones & gives the growth process a boost.
A single root, called the radicle, will shoot downwards as the new stem grows upwards pushing the seed out of the soil.
Unlike common marijuana leaves, two rounded cotyledon leaves will sprout from the stem as the plant breaks away from the seed's protective casing.
These cotyledon leaves gather energy from sunlight so that the plant can become stable & grow bigger. Once the roots develop, the first true leaves grow & the plant is not in its seedling stage.
2. Seedling Stage
The seedling growth stage is fragile & plants must receive 18-24 hours of sunlight, moist soil, & mild humidity to grow rapidly. All growers know that a full spectrum LED grow light is best for plant growth.
Because the seedling has such a small root system, it's important to not drown it by overwatering.
Once a plant becomes a seedling, it will develop more traditional-looking cannabis leaves.
A marijuana leaf is made up of anywhere between 3 to 13 fingers. The leaves produced from a sprout will appear with only one rigged finger. With new growth, marijuana leaves will develop more fingers. Mature marijuana plants will typically have between 5 & 7 fingers per leaf but can reach up to 13.
The first fingered leaves can grow up to 4 inches above cotyledon leaves & will have the notorious serrated edges. This set of leaves grow in pairs on opposite sides of the stem.
Cannabis plants are treated as seedlings until they develop leaves with a full number of fingers.
Healthy seedlings should be short with thick vegetation & their leaves should appear vibrant green in color.
During this stage, growing environments must be kept clean & free of excess moisture to ensure the plant does not become diseased or moldy.
3. Vegetative Growth
Once a seedling develops 7 sets of pointed leaves, it enters vegetative growth.
After being relocated to a larger pot, the growth of a cannabis plant soars. It's stem become thicker & grows taller, it produces more leaves, nodes, & branches, & its root system becomes more established to prepare for flowering.
This is the stage where growers will begin topping & training plants.
The spacing between nodes displays what kind of cannabis you are growing. A node is where any two branches intersect off the main stalk. When a plant is young, nodes develop in pairs. When a plant has matured nodes start to alternate. They still develop in pairs but there is more distance between them & branches are no longer parallel to one another.
There are also secondary nodes on branches that have developed from the main stalk.
Sativa plants are lanky & don't have as many leaves while Indica plants are shorter & denser.
During the vegetation stage, it's important to increase water to aid in the plant's development. As your plant grows larger & the roots grow outward, it's better to water farther away so that the tips of the roots can more easily absorb it.
During this stage your plants need an increase in warm water, a flow of dry air, nitrogen & potassium-rich nutrients, & a lot of soil space to allow them to grow 2-3 feet tall.
Similar to the seedling stage, during vegetative growth, cannabis plants should be in well-drained soil. It's important to let the plants dry out between watering to ensure they do not drown.
The growth of the plants is based on the rate leaves gather light & transform it into photosynthesis.
For indoor grow rooms, plants should be kept on an 18-hour day light cycle with a 6-hour night period. You can keep your plants on a 24-hour light cycle but plants tend to do better when given breaks & it will save you some money.
Fun fact: Since light cycles control when a plant goes from the vegetative stage to flowering, they can be kept in vegetation forever. This is a tactic used to skip the germination stage & grow plants from cuttings.
4. Pre-flowering
It can take anywhere from 7 to 14 days for a plant to enter the pre-flowering stage. Once it does the sex can be determined by the pre-flower found at the nodes. It becomes easier to figure out the sex when the plant goes deeper into vegetation.
Once the sacs on a male or intersex plant burst, the pollen can fertilize the cola of nearby females ruining the psychoactive potential of their trichomes (small gl&ular hairs). This is why it's critical for male & intersex plants to be removed before flowering.
Since Hermies have both gl&s & leaves (the reproductive organs of a cannabis plant), they can pollinate themselves & ruin your harvest. You must remove & destroy all intersex plants because of this risk.
A cola is the flowering site on a female cannabis plant where flowers grow together tightly. This is also known as the terminal bud. Healthy plants typically form one main cola from the center of their structure & smaller colas form on the outside of the plant. Trimming & training are used to increase the number of large colas a plant will form.
Non-pollinated female plants produce Sinsemilla, they have no seeds & produce more cannabinoids. Sensimilla has an exceptionally high concentration of psychoactive agents & is responsible for effects like talkativeness, increased sociability, euphoria, the munchies, & hallucinations. These plants produce large volumes of resin & fake seed bods both containing high levels of THC.
Sinsemilla is identified by the white hairs that sprout from the bracts at the plant's nodes.
Once the plant starts receiving less light per day (from 18 to 12 hours), its growth will halt & it will enter the flowering phase.
5. Flowering
The flowering stage occurs naturally when plants receive less than 12 hours of light a day. For cannabis to completely enter the flowering stage it requires periods of 10 to 12 hours of complete darkness.
You will know that your plant is ready to be harvested when the colors of the pistils on cola buds turn from white to reddish orange & the trichome heads turn from transparent to milky to opaque & finally amber.
The amber color indicates a higher CBD to THC cannabinoid ratio in its resin.
Trichomes produce THC, terpenes, flavonoids, & other cannabinoids. As flower clusters develop more cannabinoid compounds develop & the clusters become sticky from resin.
In the flowering stage, cannabis plants enjoy warm weather, medium humidity, & benefit from intermittently receiving blooming nutrients.
If you notice that the trichomes fell off, you let the plant grow too long & most of the cannabinoids are gone meaning you won't get the THC or CBD effects & will have to start over with a new batch.
Trichomes turn from cloudy white to brown once THC begins to weaken. While having some brown trichomes is okay, its a sign that the plant is ready to be harvested.
It's recommended to harvest once half the trichomes are opaque. It's believed that this method produces the highest amount of THC & the lowest levels of CBD.
Another way to determine if your plants are ready for harvest is by checking the color of the hairs that grow inside of the pistils or calyxes.
If there is a high color ratio of white to red pistils your cannabis will provide a euphoric THC high.
If the color ratio is more red to white, your cannabis will provide a calmer, CBD-stoned feeling.
If you harvest once half the trichomes are opaque & the pistils haven't turned brown, your cannabis will provide a balanced THC/CBD high.
6. Harvesting
Once it's time for harvest, the cannabis plant should be cut down into smaller branches to ease the drying process. When the plant is cut into small sections, the pieces should be strung & hung upside down in a cool, dark room.
Commercial cannabis is typically dried by applying a humidity level of between 40 & 50%. The plants should remain hanging for 7 to 14 days.
Drying is necessary to prevent fungus & bacteria from growing. By removing moisture, you can effectively preserve the life of your cannabis. Completing the drying process too quickly will result in harsh cannabis.
The curing process is optional & involves aging cannabis in sealed, airtight containers (generally mason jars) & placing them in a cabinet where temperature levels remain between 50 & 60 °F.
To avoid a decrease in airflow, jars should not be packed tightly. They must remain stored for 1 to 3 weeks & opened briefly once a day to release any buildup of gases while absorbing the fresh air.
It's believed that curing improves flavor & burn quality, & reduces the harshness.
If you are a beginner, ECO Farm marijuana grow kit can help you more.
How to Speed Up Harvest Time?
Many of our readers write in to ask about speeding up the time to harvest.
So, how long does it actually take to grow marijuana?
Short Answer: From Day 1 of your marijuana plant's life to a smokable harvest, you are looking at a window ranging between 3 and 7+ months!
Many factors will affect the total time, but the average grow takes 3-4 months.
Long Answer: These factors have the greatest impact on total time to harvest:
Plant strain – strain has the largest impact on growing time.
Desired yields – do you want to grow a few grams, a few ounces, or a few pounds?
Growing method – differing grow methods/setups can add or subtract a few weeks or even months!
Now that harvesting and trimming are complete, it’s time to cure your flowers. Curing is an essential process that removes the last of the residual water from the buds, minimising the chance of mould and greatly prolonging shelf life. Curing also enhances the taste and quality of the smoke, making for a smooth and potent experience.
If you opted to use the dry trimming method, then your flowers will be ready to cure straight away. If you chose wet trimming, then your flowers will need to be properly dried before you go on to cure them.
To do this, spread them out over some cardboard, newspaper, or, even better, a wire drying rack. Whichever you choose, make sure they are spread out over a large surface area and exposed to as much fresh air as possible. Aim for a steady room temperature of 21°C and a relative humidity of 50% to ensure a longer but gentle drying process to maintain as much flavour as possible.
Now we can move on to curing. For this, you’ll need airtight glass jars to minimise mould from taking hold. Fill each jar so it’s ⅔ full, leaving adequate room for air. This is the perfect environment for excess sugars and chlorophyll to be broken down, a process which is key for those smoother hits of smoke.
For the first two weeks of curing, open each jar once or twice per day and remove each bud, checking for any signs of cobweb-like mould. If you detect anything, remove this bud from the jar and place it in the bin. Opening jars this regularly will also serve to replace the air within the jar, keeping it fresh.
After a few weeks, the need to check your buds as much will reduce; the drier they become, the less chance there is of mould striking. At this stage, you’ll only need to check around twice per week to expose your buds to fresh air. After a few weeks, your buds will be cured; however, some growers choose to go a few weeks further to develop pristine and high-quality flavour. You can smoke-test you buds as the weeks go by to see if the current taste suits your preference.
How Much Time Per Week Does It Take To Grow Cannabis?
Now that you're equipped with the information to get you to harvest as soon as possible, let's quickly address another common question we receive about time.
Growers often write in to ask us how much time it will take per week to grow a marijuana plant. We understand that many of you have busy schedules, and want to know if growing your own weed is a realistic goal for you.
The amount of time spent growing varies greatly depending on the method you use to grow, the size you let your plants get and the skill of the grower. But that doesn't mean there isn't a growing method that's conducive to spending less time plant-tending.
The truth is, you can grow weed in only 20-30 minutes a week when you use the right techniques and get used to the process of growing. The following article reveals the best way we know to grow lots of potent bud while using a minimum amount of time to do so. We make this happen using a hydroponic style of growing known as Top-fed DWC (aka "bubbleponics").
Final thoughts
Using your own home-grown Mary Jane can be very rewarding. If you’re a cannabis user with a green thumb, then we recommend giving it a go at least once. You never know, you might find your new favorite hobby! Once you get the hang of things, you can start growing more challenging and exciting strains.
Before you start, though, it’s crucial to find out the laws in your locality. Growing weed in a state where it’s illegal can carry hefty penalties, so it’s just not worth it! Make sure you stick to the laws in your state, and you will find the experience much more pleasant.