Learn what your cannabis should look like (with pictures) so you can maximize marijuana yields by focusing on the right factors each week of the flowering stage. Know what to expect! How long does it take to germinate cannabis seeds? When to transplant seedlings? When to start vegging and flowering? Grow your knowledge about the lifecycle of the cannabis plant. Watching your cannabis plants flower is both exciting and daunting. Click here for an in-depth overview on how to guide your plants through the bloom phase.
Week-by-Week Timeline of the Cannabis Flowering Stage: 12/12 to Harvest (with Pictures)
Do you want to know what to expect when growing marijuana in the flowering stage? First, let’s talk a little bit about the beginning of your plant’s life so you can understand exactly how the flowering stage comes in. During the phase known as the vegetative stage (the first stage of life for marijuana), a cannabis plant grows about how you’d expect… like a weed! In the vegetative stage, a cannabis plant only grows new stems and leaves, and can grow several inches a day with the added ability to recover from just about anything.
Even if you run into major problems in the vegetative stage, you can bring your plant back from the brink of death simply by addressing the problem and giving your plant some TLC.
In the vegetative stage, your cannabis plant only grows stems and leaves and is resistant to problems. It grows like a weed!
However, things aren’t so rosy in the cannabis flowering stage. In the flowering stage, your cannabis plant grows very differently and is much more sensitive to problems. The tricky thing about the flowering stage is that you don’t have much room for error and big mistakes can lower your yields.
In order to maximize your yields, it’s important to know what to focus on during each part of the flowering stage. It’s also really helpful to know what to expect so you know when something is going wrong!
Week-by-Week Timeline of the Flowering Cycle (with pictures)
This marijuana flowering stage “walk through” will explain exactly what to expect week-by-week while your plant is making buds, and it’ll tell you what you need to do to ensure you get to harvest with the best bud quality and yields possible!
Week 1-3: Transition to Flowering
When growing cannabis indoors, the flowering stage begins when you change your grow lights to a 12/12 light cycle (12 hours light, 12 hours darkness each day). Getting those 12 hours of uninterrupted darkness each day gives your plant the signal that it’s time to start flowering. In a way the plant “thinks” winter is coming because the days are getting short.
Note: It’s common to think that a cannabis plant getting 12 or less hours of light is what initiates flowering, but it’s actually uninterrupted darkness that does the trick! If the plant gets any light during the dark period, even for just a minute, it won’t make buds! In fact, a flowering plant may even revert back or express hermaphroditism if it gets any light at night!
Outdoors, it’s also the days getting shorter that cause a cannabis plant to start making buds in late summer, but outdoor buds develop on different schedules depending on the local climate. This tutorial is meant to explain how a cannabis plant usually develops when grown indoors, since that is done under controlled conditions, and plants tend to grow the same way.
For the purposes of this tutorial, the flowering stage starts the day you switch to 12/12
Autoflowering strains of cannabis don’t need special light periods to start flowering, however the cannabis flowering timeline in this tutorial is a good general guideline for indoor auto-flowering strains, too. Their “vegetative stage” lasts about 3-4 weeks, so as long as you start counting at week 3-4 from seed (when they start getting their first pistils) this flowering timeline will generally apply to autos too, though sometimes they finish up faster.
During the first few weeks after being switched to a 12/12 schedule, your plant will be growing like crazy and rapidly gaining height. In fact, a cannabis plant can (and frequently will) almost double in height after the switch to 12/12. This period of super-fast and often stretchy growth is sometimes referred to as the “flowering stretch.”
Example of flowering stretch – what to expect
Pre-Stretch – just before 12/12
Post-Stretch – 4 weeks after 12/12
Although your female plants will start sprouting lots of white pistils, they usually won’t start growing “real” buds with substance quite yet. If you’re new to growing cannabis, it’s very important to note that only female cannabis plants make buds.
Did you know you can figure out if a plant is male or female while it’s still in the vegetative stage?
If your plant is male, it will start growing distinct pollen sacs and should be removed from the grow room immediately to prevent it from pollinating your female plants and causing ‘seedy’ buds. Learn where to get feminized (all-female) seeds online so you don’t have to worry about male plants.
Remove any plants growing pollen sacs instead of pistils, because they are male and won’t make buds. Plus they can pollinate your female plants and cause them to grow seeds! What if my plant is growing both pistils and pollen sacs?
Female plants should be growing pistils wherever a fan leaf meets a main stem. They look like white wispy hairs emerging from the joints
During the first few weeks of the flowering stage, you will see bunches of single leaves forming at the tops of your main colas (like in this pic). Soon white pistils will start coming out of the middle of the bunches, and they will become your main buds!
During week 1-3 of the flowering stage, your plant will mostly be producing new stems and leaves as it grows taller. Right now your plant is still very resilient and can handle problems just like in the vegetative stage. However, it’s still very important to avoid problems and take great care of your plant!
As part of the stretch, your plant will be growing out its bud sites. Stunting growth at this point could cause the plant to make smaller and fewer bud sites than it would if it were healthy and growing fast.
If you have more room in your grow space under the light to spread your plants out, or if you are running out of headroom, it is important to gently bend stretching stems down and away from the center of the plant to help maintain a flat canopy (a technique known as low stress training).
During the stretch, gently bend new stems down to try to maintain a flat, even canopy
If you keep up with it during the stretch, you can prevent any one stem from getting much taller than the others
When stems are new, they are flexible and easy to bend, but they quickly harden up and turn woody. By keeping a close eye on your plant and bending any too-tall branches down and away from the center of the plant as soon as you can, you will maximize your yields since that flat shape will most efficiently use your grow lights. If all your main bud sites are spread out and about the same height, you can increase your yields by up to 40% or more!
Spreading out your bud sites and maintaining a flat canopy can increase cannabis yields by as much as 40%…or even more!
At this point, you only have a few weeks left until you lose the ability to do any further training, so don’t miss this last opportunity to control the shape of your plant, especially if you’re running out of room!
Week 3-4: Budlets Form
The mad stretching of the first few weeks will start to slow down in week 3-4, but your cannabis plant will still be growing upward. At this point you’ll actually start to see real buds instead of just hairs (I like to call them “budlets” during this stage) and all the pistils will be white and sticking almost straight out.
“Budlets” start forming where buds will be, with white pistils sticking straight out
Your plant is going to start getting a little picky about the environment and nutrients in week 3-4 so it’s important to keep a close eye on your garden. You need to make sure your plant stays healthy all the way to the end of the flowering stage, and you’ve still got more than a month to go so you don’t want your plant to run into any major health problems now!
Be especially aware of leaf symptoms, for example: discolored/yellow leaves, or if your plant starts rapidly losing leaves. It’s completely normal to lose a few leaves at this stage, especially leaves that aren’t getting light (which often look like they may have a nutrient deficiency and then fall off, but it’s just your plant cannibalizing the leaf since it isn’t getting any more light). That being said, overall your entire plant should still be lush and green in week 3-4 while your budlets are forming.
As your plant continues through the flowering stage, it’s normal to see a few yellow or discolored leaves near the bottom of the plant, especially in the places where the leaves are no longer getting light. This isn’t anything to worry about if it’s just a few leaves as the plant is putting its energy to the top of the plant and the buds.
But it’s not normal for your plant to be yellowing or losing leaves rapidly like this
Another thing to be aware of is nutrient burn. This is what happens when you give your plants too-high levels of nutrients – the tips of all the leaves actually get “burned.” While a little bit of nutrient burn won’t hurt your plant, it’s important to try to avoid it if you can. Your plant can never recover the parts of the leaves lost to nutrient burn, so if you accidentally give too much nutrients in the future, the burning will start “climbing” up the “fingers” of the leaves. Cannabis leaves tend to look much less appealing/pretty as more of each leaf gets burned. However, even cannabis plants with severe nutrient burn can produce good bud, so don’t give up if you run into thi problem!
Try your best to avoid nutrient burn (burnt leaf tips caused by too-high levels of nutrients), as it can only get worse as the flowering stage continues
When nutrient burn starts getting bad, it can actually start discoloring your sugar leaves (the small single-finger leaves emerging from your buds). If nutrient burn reaches the base of the sugar leaves, you won’t be able to trim it off at harvest so your buds will end up with yellow/brown spots where all the leaves were burned.
Nutrient deficiencies can also cause the same problem if left unchecked. This doesn’t necessarily affect the potency but buds don’t look as good as they could have.
So to grow bud you’re proud of, you’ll want to be aware of avoiding nutrient burn from the beginning. Since your plant isn’t really growing many more leaves, you need to really care for the ones it has left.
If they haven’t already, your plants may start to smell!
Some strains like Blue Mystic and Northern Light are known for having relatively low smells, but many strains can start getting pungent quickly!
Week 4-6: Buds Start Fattening
Your budlets are fattening and soon you will have buds with substance! They will still have nearly all white pistils sticking straight up in every direction, but the buds themselves will be getting fatter every day.
By weeks 4-6, the stretch is almost over and you no longer need to pay attention to training your plant. Instead of trying to keep the colas down, from now on you’re doing the opposite – trying to hold any buds up if they start getting too heavy for your plant!
If you’re having trouble fitting your plant in your space within a safe distance from your light, your training options can start looking very grim.
If your plant has grown into the light, you may have to consider last-resort solutions like supercropping (a high-stress training technique of forcing stems to bend at a 90° angle) which you normally should never do this late in the flowering stage.
Since you don’t get many more new leaves, you need to think of your remaining leaves as armor – insurance against any nutrient or leaf problems.
Although you don’t want an excessively leafy plant, and strategic defoliation (for advanced growers) can be helpful to expose bud sites, it’s important to make sure that you let your plant keep enough leaf coverage to power the growth of buds. It may need a little extra help if something happens!
Although defoliation may be used to expose buds sites, make sure your plant still has enough leaves (“armor”) to last until the end of the flowering stage to power the growth of buds, and as insurance against any possible nutrient or leaf problems.
Although most of the pistils will probably still be mostly white by the end of week 6, the buds are getting bigger and denser every day!
Week 6-8: Buds Ripen, Pistils Darken
From now on your plant won’t be making any new leaves or stems. It has completely switched gears away from vegetative growth and all its energy will be focused on growing buds from now until harvest.
It’s normal for some of the bottom leaves to begin to turn yellow as the plant continues to put its energy in the leaves and buds getting the most direct light, though the plant should still be mostly green from top to bottom even in week 6-8.
At this point, your plant may start getting much more picky and sensitive to nutrient problems, including those caused by incorrect pH at the roots. Now is not the time to slack off on caring for your plants!
If your leaves are already turning yellow in week 6-8 it’s too early! Early leaf yellowing is likely caused by either a nutrient problem or light burn (which are both much more common in marijuanas flowering stage). React quickly to problems so you don’t hurt your yields!
Another common problem to watch out for at this stage: if you see a whole new bud or “spire” emerging out of the side of an old bud that’s already developed, it’s usually a sign of heat or light damage.
“Foxtailing” like this is caused by too much heat or light – it’s not normal bud growth! If you see this it means you need to control your temperature and light levels to prevent further damage!
From now until harvest it’s extra important to avoid too-high levels of light or heat because (in addition to foxtailing) this can discolor/bleach/burn your buds and may even “evaporate” away some of the THC / potency.
If things are going well, your buds should be really hitting their stride at this point. They will grow in size significantly over the next few weeks!
Week 8+: Flowering Ends, Final Flush, Harvest
Home stretch! You’re so close! To make sure things go smoothly until harvest, treat your plant like a movie star and attend to its every need! Very few strains of cannabis are ready to be harvested before week 8, but now we’re at to the point where some short strains are getting close to being harvest-ready!
Many growers do a final flush, which involves giving only plain water to your plants (for a few days up to a few weeks) before harvest.
Once you’ve reached week 8, buds are fattening quickly. Trichomes and pistils are maturing, though new pistils may continue to develop on the buds as they grow.
You are basically just maintaining your plant until harvest. Different strains are ready at different times, but from now on you’re going to pretty much treat them all the same. Keep a close eye on the buds, pistils and trichomes as a whole to help you figure out the best time to harvest to get the effects you are looking for.
Now is Probably the Best Time to Take Bud Pics!
Quick Tip: Want to take better bud pics? Try taking a picture of the bud in the dark with your camera flash on. Learn more tips for taking great bud pictures!
Just around 8-10 weeks is when you get to see the buds in their full glory. It’s also when the smell of cannabis often starts to get overpowering!
Your plants are probably STINKING up everything around them!
At this point it’s completely normal for your plant leaves to start yellowing, sometimes rapidly. As long as the yellowing isn’t affecting your buds and you’re very close to harvest then it’s completely normal. You probably can’t prevent this type of yellowing no matter what you do with nutrients because this is just what a cannabis plant naturally does as it’s wrapping up the flowering stage.
After Week 8 it’s normal to see leaves turning yellow, in fact there’s not much you can do to prevent it. As long as it’s close to harvest and the yellowing is not affecting your actual buds it’s ok!
Raising nutrient levels at this stage is not recommended as it won’t stop the yellowing and can possibly prevent your buds from fattening up as much as they could have (cannabis wants relatively low levels of nitrogen in the flowering stage for proper bud growth).
If buds start getting too heavy and fall over, special tools known as plant yo-yos (pictured to the right) can be hung from the ceiling and will hook around your buds to gently hold them up without damaging them.
Many growers choose to give their plants a 2-week flush before harvest to help make sure the plant has used up any additional nutrients that may affect the taste or smell of the buds.
These buds are ready to start flushing – white pistils have nearly all darkened and curled in
(learn exactly when to harvest so your buds produce the right effects)
Sometimes you’ll need to harvest your plant early due to life situations, or because the plant is unhealthy and buds are starting to look burnt or discolored. If your buds look completely done, and you’re seeing leaf symptoms getting worse, it’s often better to harvest a little early to ensure the best possible quality given the situation.
You may want to harvest your marijuana buds early if they’re starting to get damaged by nutrient or other problems. Sometimes it’s better to cut your losses than let your buds continue to get beat up! If you harvest your plants too early you can improve many unwanted effects by curing them. For example, these buds probably should be harvested before the buds get any further damage.
Harvest buds early if they’re getting damaged!
Harvest day is the best day!
(well, until the day you try your buds for the first time!
Cannabis growth stages breakdown
Growing cannabis can seem easier when the process is broken down into the 4 main cannabis growth stages. These are the cannabis seed germination, seedling, veg and bloom. At each stage the requirements for nutrients, light and water will vary. The experienced cannabis grower will know how to give the right environmental conditions at each of the stages of cannabis growth. However cannabis plants will always teach you something new to improve the way you grow. Dive into this guide to learn all you should know about the life cycle of cannabis!
|●||How long is a cannabis full grow cycle on average?|
|●||Cannabis germination stage (2-10 days)|
|●||Cannabis seedling stage (2-3 weeks)|
|●||Cannabis vegetative stage (3-15 weeks)|
|●||Cannabis flowering stage (7-14 weeks)|
|●||Other important cannabis life cycle considerations|
How long is a cannabis full grow cycle on average?
There are 4 main stages of the cannabis life cycle as it transitions from seed to harvest. Germination is often defined as the time taken from planting the cannabis seed to the point where it has produced it’s first cotyledon leaf pair. These are the first ‘baby’ (non-serrated) leaf set which is formed as the seed germinates.
|Cannabis growth stages||Average duration|
|Germination stage||2-10 days|
|Seedling stage||1-3 weeks|
|Vegetative stage||1-15 weeks|
|Flowering stage||7-14 weeks*|
The cannabis plant life cycle for a fast growing autoflower seed variety such as as Auto Blueberry or Auto Blackberry Kush could be as little as 9 weeks from seed to harvest.
Or it could be a 6 months cannabis life cycle for an outdoor seed variety. The indoor cannabis grower has full control over their plants and the environment. This allows indoor feminised seed growers to dictate the length of vegetative growth, which in turn will affect final plant size, yield and overall life cycle.
The length of the cannabis full grow cycle will depend on your choice of cannabis seeds (autoflower seeds vs feminised seeds) and whether you grow them indoors or outdoors.
|Autoflower seed vs feminised seed outdoor cannabis growing|
Cannabis germination stage (2-10 days)
Cannabis seeds are typically small, hard and dry. The colours vary from light to dark brown. The first cannabis plant stages take place after the seed has germinated. During seed germination the shell of the seed is initially softened by the moist germination conditions. It’s important to provide moist, but never soaked, conditions for cannabis seed germination in order to achieve maximum germination rates from your precious seeds.
Cannabis seeds should be germinated in dark conditions and don’t need any nutrients initially. Water is sufficient for the first few days. The tap root will emerge from the cannabis seed and grow downwards. The first set of cotyledon leaves will emerge and the cannabis grow cycle has begun! Note that these leaves don’t have the ‘normal’ serrated edges which you will see on all subsequent leaves. As all this is happening the cannabis root system starts to form.
It can take around 2-10 days for seed germination to occur. Occasionally, cannabis seeds can take up to 2 weeks to germinate. Eventually you will see the first set of ‘true’ cannabis leaves with serrated edges appear. For many growers, this represents the end of the cannabis germination stage and the start of the seedling stage.
|Dark vs white cannabis seed germination test|
How long does it take to germinate cannabis seeds?
It can vary from one cannabis seed to another. Usually you can expect seeds to germinate somewhere around 2-10 days after you begin the germination process. Occasionally you can get cannabis seeds to germinate in just one day. Sometimes it can take around 2 weeks. But usually you can expect to wait around 2-10 days for your cannabis seeds to germinate.
Can you speed up the germination process?
Not really. You need to provide good cannabis seed germination conditions and then wait for nature to do her work. If you have bought good quality cannabis seeds from a proven supplier than you can expect cannabis seed germination rates of 90%+.
Many growers have accidentally killed their plants during germination by trying to speed things up by a day or two. It definitely isn’t recommended to e.g. sand-paper your seeds to reduce the shell thickness in an attempt to speed up germination. Nor is it recommended to try to force the shell off the plant during germination. Instead, just be patient and allow the cannabis genetics to do their work.
When to transplant cannabis seedlings?
If you have germinated your cannabis seeds with the moist cotton pad method then you will simply place the germinated seedlings in your grow medium (e.g. soil or coco fibre) or your grow system (e.g. DWC or NFT hydroponic system).
Many growers that use e.g. autoflowering cannabis seeds will simply put their seedling into the final grow container. This avoids the need to repeatedly transplant the seedling to progressively larger containers. In the case of an autoflower strain with a limited lifetime, this process allows the auto to focus all the available time on growth. No plant time is spent adapting during repeated transplants, allowing your auto to reach maximum potential.
Those that grow photoperiod feminised seeds indoors can choose when the blooming process starts simply by reducing daylight hours. That gives them more time to spend progressively potting up and transplanting into gradually larger containers if they wish.
|Cotton pads germination video tutorial|
Cannabis seedling stage (2-3 weeks)
For the next 2-3 weeks after germination, the cannabis seedling will grow. The cannabis root system is essential for healthy growth and development. Experienced growers aim to deliver fully optimised grow conditions in order to maximise root growth. Give the roots waterlogged cold soil and they won’t grow well, this may result in a permanently stunted plant.
Above ground, the cannabis seedling will continue to grow. With each new set of leaves you may notice progressively more ‘blades’ or fingers on the leaves. Initially you may see 3 fingers, then 5 or 7 etc. During the life cycle of cannabis, the seedling needs less water and nutrition than it does in subsequent veg growth and flowering stages. This is one of the most delicate cannabis growing stages. The seedling needs little water and minimal nutrients.
If growing in light mix soil there you may not need to consider any grow nutrients until a week after the first set of serrated leaves emerge. Generally, a light mix soil has enough nutrition for the first couple of weeks after cannabis seed germination. After that many growers use root stimulator and grow nutrients.
If you are growing in hydroponics or coco fibre you may already be carefully using very light nutrients on young seedlings. You may prefer to use specialist low strength seedling nutrients at this stage. The goal is to keep the cannabis seedling in the nutrient sweet spot without over feeding or underfeeding. If seedlings are given excessive nutrients it can ‘burn’ the plant, permanently limiting future growth.
|Everything you need to know about cannabis roots|
How long does the cannabis seedling stage last?
Many growers consider the first 2-3 weeks after germination to be the cannabis seedling stage. These are the first couple of weeks where the seedling is most vulnerable. The seedling may only be a few inches/cm tall with a couple of sets of true (non-cotyledon) leaves.
Lighting levels don’t need to be particularly intense for cannabis seedlings, for the technically minded PPFD levels of 200-400 should be adequate. Many use T5 fluorescent tubes for cannabis seedling lighting. The delicate young seedling leaf tissue can be damaged by the intense light levels which you will need in later cannabis flowering stages.
If you do see your cannabis seedlings stretching a little too much it can help to reduce the distance between the plants and the light. With higher light intensities, the stretching should reduce. If your seedling suffer elongated stems you can gently prop up your seedling with some small wooden supports, such as toothpicks (or similar)
What does a healthy cannabis seedling look like?
You can expect a short, squat plant. The cotyledon leaves will be small in comparison to the emerging ‘true’ leaves and you will notice new leaf sets emerging from the central growing point of your plant (the ‘apex’). The colour should be a vibrant green. Any signs of yellowing is a signal that something is wrong. If your seedling has brown leaf tips it’s a sign that you have overfed your seedlings and ‘burned’ the plant. This is never a good sign and can temporarily or permanently restrict future growth.
If you have a healthy cannabis seedling it will have all the basics in place for future growth. The roots should have the space and nutrients/minerals required to grow a larger frame. The leaves will be ready to grow and absorb more light which will power future photosynthesis. Your plant is set for vegetative growth and will be ready for more light, nutrients and water.
Autoflower seed growers may already have their plant in the final grow container at this stage.
|Top 10 germination and seedling mistakes|
Cannabis vegetative stage (3-15 weeks)
Vegetative growth is the indoor cannabis growing stage where roots, branches and leaves grow but no buds are formed. Indoor growers often use 18-24 hours of daily light whether they are using autoflower seeds or photoperiod feminised cannabis seeds.
During vegetative growth the cannabis plants gradually grow in both height and width. Nitrogen rich nutrients are particularly useful in the vegetative growth stage. The first sets of cannabis leaves grow gradually larger and new leaf sets are formed. As the plant grows it’s requirements for nutrients, water and light will all increase. Light levels can be increased from around 200 PPFD to nearer 400-600 PPFD – your light manufacturer should be able to detail the PPFD levels at various hanging heights.
How long should a cannabis plant stay in veg?
Those growing photoperiod feminised cannabis seeds can select the length of the vegetative growth stage. Often it’s around 4-6 weeks for many growers. But some growers, e.g. SCROG growers (Screen Of Green method), prefer very long periods of ‘veg’ growth, in extreme cases up to 15 weeks or so. However, SOG growers (Sea Of Green method), may not give their plants any veg growth and instead put them straight into bloom conditions.
Those growing autoflower seeds will not be able to dictate the length of the vegetative growth phase. Instead the autoflower seed genetics will determine the point at which it automatically transitions from veg to bloom. It does this without any change or alteration to the light cycle. Autoflowering cannabis seeds grow from seed to harvest under the same light cycle, typically 20 hours of daily light. Photoperiod feminised cannabis strains only commence bloom when indoor light hours are reduced to 12 per day.
|SOG vs SCROG cannabis growing|
How does a healthy cannabis plant in veg look like?
Much depends on the length of time the plant has been in the vegetative growth stage for. A feminised strain with 15 weeks of veg growth could have filled a very large SCROG screen. Whereas an autoflower plant in veg may be perhaps 10-20cm tall, perhaps 3 weeks old and ready to start stretching once bloom begins. Much depends on your cannabis genetics and grow style. But you can expect to see a medium-sized plant with healthy green foliage, but no buds.
Why does my cannabis plant want to flower in the vegetative stage?
The cannabis flowering stage follows veg growth. Cannabis plants are genetically geared towards bloom. It’s the only chance for cannabis to produce seeds and produce the next generation of plants. You may see pre-flowers at the nodes between the stem and branches. Autoflower genetics don’t hold back. As soon as they are ready, autos start to transition from veg to bloom. During this process the auto exhibits features of both veg and bloom.
Cannabis flowering stage (7-14 weeks)
During the cannabis flowering stages, the female plant produces buds and resin. The flowering stage follows the vegetative growth stage. When growing autoflowering cannabis seeds, the transition from the vegetative stage to the flowering stage happens automatically (hence the name, autoflowering).
When growing photoperiod feminised cannabis seeds, bloom begins indoors when the daily light hours are decreased to 12. Outdoors, feminised strains sense the shortened daylight hours as autumn/fall approaches and bloom begins. However if you are growing at equatorial regions the plants can sense the short days immediately.
During the cannabis flowering stage, the plant will require gradually increased levels of nutrients and water. Phosphorus will be required in greater quantities as the plant biochemistry changes. During the cannabis flowering stage the plant biomass can increase dramatically.
Intense light levels can be used in bloom, often with PPFD levels of 600-900. More light can deliver heavier yields. Some professional cannabis growers used PPFD levels of around/over 1000 and may also supplement with Carbon Dioxide to further boost yields.
The length of the flowering stage depends on the genetics. 7 weeks of bloom is required by fast flowering indica strains such as Bubba Island Kush seeds. But a slow blooming Haze may require upwards of 14 weeks in bloom.
The following cannabis flowering stages are shown in week by week pictures, below.
How to tell if a cannabis plant is ready to bloom?
Knowing when your plant is ready to be flipped from veg growth to bloom is one of the most important decisions you will make. But first you may wish to consider a few points related to the timing of the cannabis flowering stage.
• The height of your grow room may be a limiting factor. If you have restricted vertical growing space you may prefer to have minimal veg time.
• Are you growing indica or sativa cannabis seeds? Sativa strains may stretch dramatically during bloom. Take this into account when deciding if your cannabis plant is ready to bloom.
• Growing clones or seeds? Clones don’t always have well established root systems and can take a while to create one before being flipped into bloom.
• Outdoor plants can also be forced into early bloom if you have a greenhouse equipped with blackout blinds. Otherwise, they will choose their own moment to bloom as daylight hours shorten.
• Which growing method are you using? If using the SCROG method you may wish to wait and give the plant a long veg stage. If using the SOG method you may want to offer minimal veg time or even none at all and grow from seed to harvest under 12/12 light
• Which region/climate are you growing in? If you’re growing in tropical equatorial regions you may want the most sativa dominant strains with the most stretch. That’s because the plants go into flowering more-or-less immediately. In more temperate climates, the plants commence bloom as daylight hours shorten. For Northern Hemisphere growers (Europe, USA etc) this often happens around August.
|Power Plant grown from seed to harvest under 12/12 light|
How long does it take for cannabis to start blooming after switching the light cycle?
Once you switch the light cycle to 12/12 (12 hours of daily light) the plant undergoes plant hormone changes as it senses the shorter days.
The plant hormones cause the plant to prepare for bloom. Over the following week or so you will see the changes on the cannabis plant as she gets ready to stretch and produce flowers. You may see female pre-flowers producing a couple of pistils (hairs) at the node between the stem and a branch.
However you can expect to wait 1-2 weeks before you start to see flowers starting to appear. With certain sativa and hybrid strains it can take 3-6 weeks before any significant flower formation.
How does a healthy cannabis plant in flowering look like?
Initially you may notice areas of light green foliage at the eventual points where buds will eventually form. You may also notice the plants stretching, with increased internodal distance.
Growers monitor their cannabis flowering stages week by week. Some like to consider the cannabis flowering stage as 3 separate mini-phases; early bloom, mid bloom and late bloom. As your cannabis plant flowers the weight of buds and resin should increase as harvest point approaches.
During the cannabis flowering stage you will notice that your plant appetite for nutrients reaches maximum as it produces bigger buds and more cannabinoid-containing resin. The ratio of required nutrients will change too. Less Nitrogen (N) is required and increasing amounts of Phosphorus (P) and Potassium (K) are needed to support heavy harvests of compact flowers.
During the first few weeks of bloom your plant will stretch. A sativa may stretch to 2-3 times the height it was at the end of veg. You will see increasing amounts of pistils being produced and the buds start to form and eventually fatten up. After around 5 weeks of bloom the cannabis plants have generally stopped stretching and the buds start to get larger.
As harvest approaches, the pistils start appearing as orange rather than white.
How to tell when your cannabis buds are ready for harvest?
Your cannabis seed supplier should give an indication of the approximate length of the flowering stage. This is a guideline rather than a fixed rule and it may indicate the typical earliest harvest point rather than the recommended harvest time.
Environmental conditions and the specific phenotype will determine the actual harvest date. In addition, you may have a preference for early, mid or late harvested buds.
There are various cannabis bud growth stages. They start small and gradually pack on weight and resin as they grow. Some growers like the slightly heavy effects (and more generous yields) offered by allowing the buds a week or two extra in bloom.
There are different cannabis trichomes stages to consider. Immature buds tend to have clear trichomes. As the buds approach harvest the trichomes become cloudy and eventually start to produce amber (or even red) colourations. Many harvest their buds as the trichomes are transitioning from clear to cloudy.
|Understanding cannabis trichomes|
What to do in case of early or late flowering?
If your plant flowers early you can look forward to an earlier harvest. A late flowering plant will generally have enjoyed more time for veg growth, so you may be able to look forward to a heavier harvest.
When growing autoflower seeds you may find some plants will be ready to harvest a week or two before the slower phenotypes. Remember each plant is different. Try to time the harvest so that you have buds of the perfect maturity level for your personal tastes. Some growers love the lively energetic buzz from an early harvested plant. Other growers will always wait an extra couple of weeks to ensure that their plants have a high proportion of amber trichomes which can produce heavier effects.
What really matters to the home grower is that they:
• are growing the best cannabis seeds for them personal needs and,
• they select the optimised harvest date which provides maximum enjoyment and satisfaction for their recreational or medical needs.
Other important cannabis life cycle considerations
There are different cannabis growth stages as well as different cannabis flowering stages. The experienced grower understands the various environmental, nutrient and lighting requirements at the various stages of cannabis growth.
What stage of growth does cannabis produce trichomes?
This can depend on the specific cannabis seeds being grown. Trichomes can be seen even on young plants though they can be microscopically small. As the plant matures the amount of trichomes increases dramatically. When growing photoperiod feminised cannabis seeds you may see the first trichomes around 3 weeks into bloom. Over the following month trichome production is heavy and gives the plant a frosty appearance, as if sprinkled with sugar.
When growing autoflower seeds, trichome production tends to start around 4 weeks after germination. In the following weeks, trichome production steps up a gear as the buds gain weight. Aroma also increases as more and more trichomes are produced.
What stage of growth does cannabis stop growing?
During flowering, most photoperiod cannabis plants stop stretching after around 4-5 weeks. After that point most of the growth happens on the buds. For autoflower plants, stretch tends to stop around 6-7 weeks after germination. At that point the bulk of the plants energy is focussed on bud growth and resin production.
But it’s worth adding that these figures are only approximate. Much depends on the specific cannabis genetics that you are growing, your environmental conditions and the grow method.
How long should the harvested buds be left to dry?
Harvested buds are typically left for 7-14 days to dry before being transferred to the curing jars. When the branches ‘snap’ (rather than bend) it’s an indication that the plant is dry enough for curing to begin.
How long should the harvested buds be cured?
Many would say that a month or two is a realistic minimum to allow the taste and aromas to fully develop. Keeping your cured buds in jars even longer isn’t an issue. Many people feel that a 6-month cure with your jars in cool/dark conditions is a great way to maximise taste and aroma.
How to keep a consistent cannabis growth timeline?
When growing photoperiod feminised cannabis seeds the growth timeline is up to you. You can offer minimal veg growth for a SOG grow or several months for a SCROG grow.
Autoflower seeds, on the other hand, have a cannabis growth timeline of their own. They, not you, decide when to start blooming. Good quality auto seed suppliers should be able to give you a good idea whether they are likely to have a growth lifecycle as fast as 9 weeks e.g. Auto Blueberry seeds or a slow growth lifecycle of 12-15 weeks e.g. Auto Ultimate seeds. Note that the autos which take longer to grow may well deliver very heavy yields.
Outdoor cannabis growers should note that the different regions you live in can also determine how many daylight hours per day you will have. That will have a huge influence on your outdoor cannabis lifecycle (or growth stages). Equatorial cannabis growers have 12/12 light (or thereabouts) almost all year round. This means you won’t have any veg time at all if you grow outdoors.
Understanding the cannabis growth stages is key
With an increased understanding of the different cannabis growth stages you will find your control and enjoyment of cannabis cultivation will increase. As well as optimising your grow environment and improving your understanding of the cannabis grow cycle be sure to select the best cannabis seeds for your personal grow situation. The choice of cannabis seeds may seem large and possibly confusing.
If so please check out the Dutch Passion Seed Finder which asks a few simple questions before recommending the seeds which best fit your needs.
The Flowering Stage Of Cannabis Week By Week
Slip-ups during the flowering phase can significantly affect the size and quality of your harvest. With a few simple tricks, however, you’re guaranteed a great harvest every time.
Cannabis cultivation, cannabis history, cannabis culture
- The first few flowering weeks (weeks 1, 2 and 3)
- Weeks 6, 7 and 8 (late flowering stage, right before harvest)
- Pro tips for a better harvest
- Happy budding!
When the light cycle provides your cannabis plants with longer hours of uninterrupted darkness, they enter the flowering stage. Your plants will stop growing and instead put their energy into producing buds (flowers). Outdoors, this will normally happen when the days get shorter around the end of summer. When you grow indoors, flowering will begin once you switch your lights to 10-12 hours of darkness.
For most cannabis strains, the flowering period will last about 7-9 weeks, although some sativas require even longer for their buds to mature.
What happens during flowering and at what exact time can somewhat vary depending on the particular strain you are growing. So don’t expect your plants to follow this schedule to the T; see it more as a general guideline that you can go by. Let us look at the flowering phase of cannabis week by week.
The First Few Flowering Weeks (Weeks 1, 2 and 3)
When the flowering period starts, it isn’t an abrupt change in your plants’ growth. Cannabis won’t just stop growing and then go into flowering right away. In these first weeks of flowering, many cannabis strains may indeed undergo a considerable growth stretch. This is important to know when it comes to feeding your plants properly, but also if you want to give them sufficient space to grow.
|(Week 1)||(Week 2)||(Week 3)|
Week 1 (Transition Stage and Stretch)
In the very first weeks of flowering, your cannabis plants will be in the transition stage. Thinking that winter is not far away and that she will soon have to carry a big load of bud, your plant will likely grow rapidly. Some strains can almost double in height during this time. Because of the fast growth that your plant is undergoing now, this early flowering phase is also known as the stretch phase.
While your plant is putting in quite some overtime to gain size and height, she will grow a number of new leaves mostly at the top of the main colas. Your cannabis plant is busy growing “green stuff,” like leaves and stems so she can become stronger and sturdier.
Important things to know in this early stage of flowering.
LST Plant Training Clips
Although your plant has officially entered the flowering phase, she will now have an increased need for growing nutrients. You should not abruptly change your nutrient schedule and use flowering nutrients from one day to the next. It is usually recommended that you continue to give growing nutrients for at least one more week once flowering starts.
With the stretching of cannabis in early flowering, you may possibly want to think about training techniques such as low stress training (LST). This is where you bend the stems down and away from the centre of the plant so you can get an even canopy for a more efficient use of your grow lights. This can help you obtain much better yields later on.
In week 2 of flowering, you may spot the first white pistils growing on your female cannabis plants. These fine and wispy white hairs will develop at those locations where the big fan leaves meet the main stem. It is these fine hairs that will later become buds.
If your cannabis plant happens to be a male, it won’t grow these “hairs,” but will instead grow small pollen sacs. Should you grow regular, non-feminized plants where you don’t know their gender, now is the time when you should “sex” your plants so you can separate the males from the females. The males won’t grow buds and will also pollinate your females, causing them to grow seeds. This is something you do not want to happen.
To properly feed your plants once they start to flower and to initiate the first signs of growing buds, you should check your nutrient manufacturer’s schedule. It is normally around this time at week 2 where you will have to increase flowering nutrients to help your plants reach their maximum yield potential.
Your cannabis plants have still not entirely stopped growing and will now be about 50% bigger than what they were just three weeks earlier. Although still stretching a bit, the stretch will now gradually slow down and soon come to a complete halt.
At the locations on the plant where you previously saw some hairs, you can now see the first signs of real buds developing. There still won’t be many resin glands and trichomes on your plants, which means that the smell won’t be too pungent yet either.
This phase of flowering where your plant is starting to spend increasingly more energy on growing flowers is particularly critical. Make sure that the nutrients you give are appropriate and check the labels for the recommended dosages.
As your plants become more picky, you should check for potential deficiencies that could manifest in various ways, such as discoloured, yellowing leaves or loss of leaves entirely. At the same time, you should also check your plants for signs of possible overfeeding (“nutrient burn”) that could show up around this time as well. Nutrient burn will usually show in the tips of the leaves becoming discoloured. If this happens, you need to cut down on feeding.