Cycle of Life: What Are the Stages of Growing Cannabis?
There are several distinct stages in the life cycle of a cannabis plant. So what are the stages of growing cannabis? This quick guide will run you through the essentials.
Stage 1 – Germination
This is where it all begins – where your tiny seed will swell and burst in the presence of warmth and water, until its hard, tough casing finally cracks.
During this step to growing cannabis, your seedlings need only water and warmth to grow.
They don’t even need light, and may actually suffer stress if exposed to too much light.
So it’s perfectly fine to keep them in a dark cupboard or similar for the first couple of days – just make sure that they are kept warm and sufficiently moist!
Most growers germinate seeds in small trays, or simply on a scrap of cotton wool well-soaked in water.
What Happens During Germination…
- First, a tiny root emerges, known as the radicle. This is the principal taproot from which all other roots branch out (except for some “adventitious” roots that may grow later, straight from the stem).
- After the radicle has established itself, the next step is the growth of the stem and the first leaves – the cotyledons. These two “proto-leaves” are rounded, soft and smooth – very different from the serrated “true” leaves that will follow next.
- By the time the cotyledons have emerged, you should get your seedlings transplanted into your soil (or whatever your chosen medium is) as soon as possible.
- Once they’re transplanted, you’ll need to give them light so that they can move on to the next stage of cannabis plant growth – vegetative growth.
Stage 1(b) – Rooting
When you’re growing from clones, the “first step” in the life cycle of a cloned plant is actually the rooting stage!
To make clones, cuttings are taken from a mother plant, and quickly placed in a warm, well-lit, and moist environment.
Moisture is essential, as the plant no longer has roots and needs to keep its tissues hydrated.
When subjected to this procedure, the cuttings respond to their change in environment, and express rooting hormones in stem tissues in order to encourage the growth of new roots.
Typically, growers use a propagator (often not much more than a plastic box with a lid), and sometimes a heating pad to make clones.
The propagator helps hold moisture, and the heating pad obviously helps to maintain temperature.
Just remember to open the lid of the propagator at least once a day to allow excess moisture to escape.
What Conditions Are Needed For Rooting?
- Usually, rooting of clones takes 7-10 days.
- Relative humidity levels of 80-90%.
- Temperatures of 75-85 F.
- 20+ hours of light per day. are great for rooting.
Any hotter or more humid than this, and your clones may well succumb to mold before they ever get a chance to root!
By now your clones should be rooted and ready to transplant, and will behave pretty much like any other cannabis plant in later stages of growth.
However, there are a few differences.
Clones often aren’t quite as vigorous as their seed-grown counterparts, partly as they don’t have a radicle (taproot) and instead have a network of much smaller adventitious roots.
Stage 2 – Vegetative
At this stage of growing cannabis, your plants should have established the beginnings of a root system, and will really start to put a lot of energy into growing stems, branches and leaves.
The more time you are able to keep your plants in this stage, the bigger they will get – and if you veg for, say, 2-3 months, you could end up with absolute monsters at the end.
Many growers, especially indoors, limit the length of time they keep plants in veg, so that the eventual size of the plant is limited. This strategy also ensures that the overall life cycle of a plant is reduced.
Key Points About The Vegetative Stage
- Generally, cannabis plants grow vegetatively when they are exposed to 18 hours of light per day.
- Indoor growers usually veg for around 1-3 weeks before switching to flower.
- Young plants should be positioned close to the light to avoid stretching.
- Lights used at this stage of cannabis growth should be a little more blue than those used in flower.
- Lights with too much of a red/far-red spectrum may encourage stretching.
- Outdoor growers have less control over day length, but can practice light-deprivation techniques to kick off flowering early.
- The optimum temperature and RH for vegetative growth of cannabis is 68-86 F and 40-70%.
Stage 3 – Flowering
The penultimate of the steps to growing cannabis is arguably the most exciting and fascinating – the flowering stage!
This is where you will see the vegetative growth slow down and finally stop, and the growth of beautiful, pistil-fringed flowers.
In the first two weeks or so of flowering (and this depends heavily on variety!) your plants will continue to grow vegetatively – this phenomenon is often called “stretching”.
This why it’s important to limit the size of the plant – many indoor growers have let their plants veg for a little too long, only to find that they reach gigantic, unmanageable proportions when they’re done stretching.
What Happens During Flower Growth?
- To flower most cannabis strains, all you need to do is switch the light cycle from 18 to 12 hours per day.
- By around week 2 after switching light cycle, stretching should slow or stop.
- Small, sparse flower calyxes and limited crystal will be present at this point.
- By weeks 4 or 5, flowers should already be starting to plump up and form dense clusters.
- Structure, density and other characteristics of your flowers depend heavily on the variety.
- The generally-accepted optimum temperature and RH for flowering cannabis is around 68-82 F and 40-60% RH.
Environmental Factors To Consider
As well as variety, environmental factors are hugely important in determining how you plants will grow.
On top of this, different strains may respond very differently to different variables.
Some may hate excessive humidity, while others may not be able to tolerate excess heat.
- If temperatures are too cold, flowers could be smaller than average.
- Too hot, and they may grow very large flowers but be low in trichomes, and/or experience heat stress.
- Too humid, and they may form mold.
- Too dry, and again, you may limit flower size.
- However, you may significantly boost terpene levels if you keep RH below 40% during the final two weeks of flower.
Stage 4 – Maturity
The final stage of growing cannabis is maturity.
At this stage, the leaves will start to yellow and die off, and the rate of bud growth will slow right down.
By now, most of the pistils that fringe your flowers should have turned brown, pink, orange, or similar – although some varieties stay relatively white.
If you use a magnifying glass or loupe at this stage, you should be able to see the trichomes (the resinous, mushroom-head stalks that cover the leaves and buds, and that contain the cannabinoids and terpenes).
Before your plants reach maturity, the trichomes are translucent and clear.
When your plants are mature, these trichomes should mostly have changed to a milky-white color. Some trichomes may even have changed to amber.
A good rule of thumb is more than 50% milky white, and no more than 10% amber.
When your plants are definitely ready, it’s time to cut, dry and cure them. We’ll talk more about that in future articles – for now, we hope you have enjoyed our guide to the stages of growing cannabis!
Can I leave grow lights on for 24 hours?
Wondering should you leave grow lights on for 24 hours straight is one of the common questions when growing weed. Let’s explore this topic in-depth and find the best solution.
With marijuana being allowed for more than just medical purposes in several countries, this industry is starting to blossom, literally. Many started growing weed at home, for many obvious reasons – with quality, lower costs, and safety being the most prominent ones.
As a conscious grower, you should ought to provide the best conditions for your plants to grow and bring the best yields. Lightning is one of the most important aspects of successful growth & plant development, so having it set in order is a must.
Let’s figure out should you leave grow lights on 24 hours and why!
The current state of the topic
Currently, there’s a lot of debate going on should you keep the light on 24 hours without stopping. The main reason behind this ongoing debate lies in the yields and plant development, alongside personal opinions and experiences of individuals.
On the other hand, a lack of firm evidence is the biggest possible contradiction to all the opinions stated online, including message boards, forums, groups, and social media. It all ties together to the point that there’s no right answer.
After researching the topic for a while, I realized that people form their opinions based on their personal experiences, and base their assumptions on their previous experiences with growing.
Adding the internet to this equation as a factor, and a possibility for everyone and their dog to state their opinion makes finding the truth quite difficult.
For example, the cannabis growers in the States have separate opinions, and could be classified into two groups:
- “24-hour lights on” group
- “Anti 24-hour lights on” group
The former group of weed growers claims that the photosynthesis is the core of growth & development, and it’s an absolute must for plants. These claims are coming from the basic definition of photosynthesis – which states that plants use the energy from the light (the sun) and transform it into usable energy – carbohydrates. By stimulating this process 24-7, growers ensure that the plant is growing to its highest potential and gain the most biomass possible.
We could agree that photosynthesis is a necessity for proper development and thriving, there’s no doubt about that.
On the other hand, the second group addresses the plant’s natural order of life & functioning. The 24-hour-lights-off is preached because the darkness allows the plant to breathe, consume the carbohydrates stored, and rest from intensive photosynthesis.
That’s where the microbes which are fed into the rhizosphere (root system + soil) get the proper resting period which makes them not “overwhelmed” by constant photosynthesis. This results in the healthier plant overall; less robust stems, bulbs, leaves, with more defense to diseases.
Furthermore, the end product that comes from a plant grown in cycles which involve darkness (18/6, 12/12, 14/10, etc) is of better quality, especially considering cannabinoid & terpene levels (both indicate the quality of the plant and the product – the more the better).
The above-mentioned situation and divide of thought aren’t really precise & definite, because growing a plant involves many more factors & conditions, which could (or could not) be manipulated.
The plant itself is the first variable in the equation; many species react to light differently and require a different amount of it throughout the day/week/lifetime.
Since we’re focused on growing weed and best practices in this branch of the science (no pun intended), we’ll disregard the other types of plants.
By definition, the plant of cannabis classifies into photoperiod plants, which means it reacts to both light and darkness. There are also auto-flowering cannabis plants, which will be explained later.
Simplified to the core (there are huge studies about this field), this means that the cannabis grows under while being lit, and blooms during the darkness. When considering what is required for best yields and best end product, the combination of light and darkness in growing appears as the best one.
But, the situation isn’t that simple to come to a conclusion that easily. There are more factors included in the process of growing & proper lightning.
Deeper into the rabbit hole we go…
Acknowledging the above-mentioned, we have to address the plant next. Throughout the growth & development, the plant of cannabis goes through several phases, each having its distinctive requirements and best practices.
- Vegetative stage
- Flowering stage
Also, both stages have significantly different practices when it comes to the location of the plant: indoors or outdoors (more on that later).
The vegetative stage starts with planting the seed and starting with the initial sprout. During this process, the plant is developing stems, leaves, and overall size. A photoperiod cannabis plant can stay in the vegetative stage almost indefinitely, as long as it receives less than 11-12 hours of darkness per a 24-hour cycle.
This means that you can keep your plant (if you have the right type) in this growth & development state for as long as you’d like, and eventually reach an impressive size.
The flowering stage starts after the plant starts receiving 12 or more hours of darkness. During this process, the growth is not as quick as in the veg stage, and the plant starts developing buds. A properly educated and careful-enough grower can put this fact into good use, and maximize growth and produce, which is often the case in growing cannabis for commercial purposes.
Where do you grow?
One of the biggest differences in growing cannabis comes from the environment – outdoors or indoors. Both environments can stimulate the plant in a great way, but both will require specific conditions & equipment and will yield results based on your engagement and investing.
Growing outdoors: Pros & Cons
The natural way to grow influences when you’re going to plant, water, and releases you from the hustle of proper lighting. When you’re growing outdoors, you just have to be careful when you’re going to start.
It all comes down to the geographic zone you’re in. You should plant during the spring season when the nights are getting shorter. The plant will grow slower and start flowering when the nights start to get longer, in the colder part of the year.
You might not get the exponential growth and plant/bud size, but the plants will surely be healthier compared to the ones grown indoors. (presuming you’ll handle the fertilizing, watering, and overall care about your plant)
By growing this way, your costs will be much lower, and you’ll end with high-quality cannabis with a high level of THC.
On the other hand, you’ll have fewer buds per plant, and smaller plants overall, which might be ok if you don’t want to commit too hard and invest a good chunk of money into equipment.
Growing indoors: Pros & Cons
If you grow indoors, you have full control over the plant’s environment, such as the airflow, the temperature, and the type of lightning. Most importantly, you decide how long you’ll treat the plant with lightning cycles.
Speaking of lightning, there’s a big difference in types of lightning used in different stages of plant development. Having a fancy HID, CFL, or LED grow light can bring you tremendous growth and prosperity, but a poor choice can also bring your plant down and wither it to a low-quality bush.
Lights can be classified in the spectrum & provide the required illumination and stimulation for the plant in a specific stage. Here’s the image that explains what is best for a cannabis plant in different growth stages (Courtesy of RoyalQueenSeeds).
As you can see, the UV lights are the best during the vegetative stage, while the infrared spectrum stimulates the flowering cannabis plant the best.
It’s important to keep in mind that watering during the flowering stage must be on par with the lightning because the stronger infrared spectrum produces a lot of heat and dries out the plant.
Important: Never leave the infrared light on your cannabis plant for more than 12 hours.
By growing indoors, you can stimulate your plants to reach exponential growth, and keep them in a healthy state by providing perfect light spectrum and the perfect amount of lightning in all stages. (presuming you’re handling other areas of proper plant care)
On the other hand, you’ll have significant costs for equipment and the dreaded electrical bill.
Conclusion: leaving the lights on 24 hours – yes or no?
Now we get to process the deeper knowledge & information:
When considering all the above-mentioned facts, the answer to the burning question – should I leave the grow lights on for 24 hours – manifests itself:
|Short answer: It depends on you – what your goals are, and what you’re trying to grow/produce.|
The longer answer is as follows:
The 24-hour periods are very good for the vegetative stage if you’re trying to maximize the growth, but you should be careful not to overdo it because the plant won’t have the proper growth process and eventually will become prone to illnesses and will yield lower-quality results.
How tall cannabis plant is at 3 week og veg?
First time grower, 4 plants, my oldest just hit veg state 4 days ago. about 4 inches tall, on it’s 4th set of leaves, 4 days ago it just sprouted the second set. I’ve counted a set of leaves every 2 days. Space your watering schedule, let the roots dig in. Dry the soil, water, dry the soil, water.
Here is my rant. been saving it, I can’t seem to grasp indica and sativa visually. I see tall skinny plants, I think idie kids with skinny jeans and think. Indica. So, clearly I see the opposite with sativa strains, and that visual stereotype drives me insane. anyways. 4th set of leaves, 4" tall, i’m thinking the short fat kid strain.