Stages of Growing Cannabis
Cannabis, weed, marijuana, kush, ganja – whatever you want to call it, it’s now legal to own and grow in the state of Virginia. So what does this mean for those interested in growing it?
Growing Cannabis for the first time can be quite overwhelming. A quick Google search will lead you to hundreds of results with more information than you can ever sift through. There’s so much to learn – lighting, pH, soils, training methods, curing, and so much more. Where does one start?
It’s really easy to fall down the rabbit hole of information online. The sheer amount of information can almost hinder you when you’re first getting started. I think it’s easiest to just get started and learn as you go.
Starting with gaining a general understanding of the stages of growing Cannabis is a great place to begin before you try growing for the first time. It will help you have a decent idea of what to expect along the way.
How long does Cannabis take to grow?
How long Cannabis takes to grow can vary based on the variety of the plant and conditions it is grown in. On average, from seed to harvest, it takes anywhere from 10-32 weeks (about 3-8 months). It’s a quicker process if you start with a clone (rooted cutting) or an autoflower seed. The biggest variability in how long a marijuana plant takes to grow will happen in the vegetative stage—after the seedling phase and before flowering.
Stages of Growing Cannabis
Every plant begins with a seed. Cannabis seeds should be germinated just like any other seed. They can take anywhere between 3-10 days to germinate, although it can happen in as few as 24 hours or as long as 2 weeks. To germinate, you can place the seeds in a damp paper towel, which you should then place in a dark place, such as inside a drawer. Check on them after a few days to see if the primary root, called the radicle, has emerged. This will look like a little white “tail” coming out of the seed. Once germinated, move them to damp soil.
Alternatively, you can place the seeds directly in damp soil to germinate and grow, without having the trouble of moving them. For this method, I would recommend a seed starting mix. These are usually lighter and fluffier than traditional potting soil, which gives your fragile germinating seeds a start on the right foot. We carry Coast of Maine Sprout Island Blend Organic Seed Starter Mix. It has additional perlite that aerates the soil and helps prevent damping off. It also has mycorrhizae, worm castings, lobster meal, hen manure, and kelp to get your plants off to a healthy start.
2. Seedling Stage
Once your seed has germinated, it’s now time to move the germinated seed from its paper towel to a growing medium. If you started them in a seed starting mix, you will want to move them from the seed tray to a larger pot with a high-quality potting mix, such as the Coast of Maine Stonington Blend Grower’s Mix. This is a super soil, that works especially well for growing Cannabis. It contains mycorrhizae, kelp, alfalfa meal, fish bone meal, worm castings, perlite, manure, peat, coir, and lobster compost that feed your plant throughout the growing cycle, with no need to use additional nutrients.
Plants are considered seedlings for about 2-3 weeks after germination. During this time, the plant should be moved to a spot with direct sun, if growing outdoors. If growing indoors, set your grow lights to run for 16 hours a day.
3. Vegetative Stage
After the seedling stage, Cannabis plants move to a vegetative stage. This is the time when the plant focuses on leaf production. It will not produce flowers at all during this stage, as the plant needs to grow plenty of leaves to take up enough photons (sunlight) to create the necessary energy to produce large flowers. The vegetative stage can last anywhere from 3 to 16 weeks, depending on the variety.
During this stage, indoor plants need 16-18 hours of light per day, and outdoor plants need at least 6 hours of direct sunlight (“full sun”), plus several hours of indirect sunlight. They will also need plenty of Nitrogen during this point, as Nitrogen is the nutrient that promotes healthy leaf growth.
The flowering stage is the last stage of the Cannabis plant life cycle. This is the time when your plant will stop putting as much energy into leaf growth and will instead focus that energy on creating the flowers (buds), which are used for medicinal and recreational purposes.
Stages of Flowering – Source: Katie Plummer
Cannabis is triggered to flower when the hours of light it receives are reduced. If you’re growing outdoors, you’re at the whim of the seasons and will have to wait until the sun starts to go down in fall for it to flower and then harvest. If you’re growing indoors, you get to play mother nature and can force your plant to flower at any point. When you’re ready for plants to start the flowering stage, change your lights to a 12/12 cycle ( 12 hours with the light on and 12 hours with it off ). You will see signs of flowering in 1-3 weeks . On average plants will be ready to harvest after 8-11 weeks of flowering.
Your plant will be ready to be harvested once flowers are compact and the pistils turn orange/brown. These pistils look like “hairs” coming out of the flowers.
To dry your Cannabis, hang sections of the plant upside down in a dark, cool space, such as a closet. You want to aim for 55-65% humidity and 60-70°F in the spot that you’re drying your plants in. Prolonged periods of light, friction from handling, and humidity/dampness can degrade resin glands, so you will want to avoid all of these.
During the drying process, plants lose roughly 75% of water weight, which increases the cannabinoid to weight ratio. It also helps equalize moisture content, preserve cannabinoids, and shed chlorophyll.
Cannabis is ready to trim once the stem snaps when bent, typically after 3-7 days of drying.
After your plant has dried, it’s time to trim! Trimming makes your fingers very sticky, so wear gloves if this is something you want to avoid. Simply trim off the larger leaves and stems. You can leave smaller sugar leaves if you’d like, as these still contain a good amount of cannabinoids and terpenes that provide the medicinal properties of Cannabis. It’s all personal preference of exactly how much you trim off. And you can save all the trimmings to make edibles, tinctures, salves, and more.
Curing is an essential part and the last stage in growing Cannabis. It helps the buds achieve full aroma. Curing is as simple as placing your freshly trimmed buds in a glass jar with a lid, like a mason jar. You’ll then want to place the jar in a cool, dark place, such as inside a drawer or in a cabinet.
During the first week of curing, you will want to “burp” your jars. This means you should open the containers once or twice a day for a couple minutes to allows moisture to escape and replenish the oxygen inside the container. After the first week, you only need to burp containers once every few days.
You should allow buds to cure for at least 2 weeks, but some people choose to cure for as long as 6 months. This helps stop the loss of moisture and to preserve flavors and aromas.
How and when to transplant cannabis plants
Transplanting is the process of “re-homing” a cannabis plant, or moving a plant into a bigger pot with more soil as it grows bigger.
Growers typically start off the cannabis growing process by planting many seeds in small pots because they don’t know if all of them will sprout—or germinate—and they don’t know if all of them will be female.
Only female cannabis plants produce buds, so if you start growing from regular seeds, you will have to sex them out and discard the males.
Why is transplanting marijuana plants important?
Transplanting gives a marijuana plant’s root system more space to spread out, allowing the plant to grow healthy and strong and to flourish.
When roots become cramped and can’t spread out they can get tangled and become “rootbound”—this will effective choke the plant, leading to a stunted, sickly plant, and can even kill it. A healthy root system will lead to a healthy weed plant.
A plant’s container will determine how much the roots can stretch out, and therefore how big your plant will get. A container that’s too small will stunt it.
You don’t want to plant a seed in a giant pot because you could potentially waste soil if the seed doesn’t make it. Also, if growing weed outdoors, it’s hard to plan out a garden and where to put your seeds in the ground if some seeds don’t make it.
Most weed growers start seeds in small 4-inch or 1-gallon pots when germinating.
For the seeds that do make it, they will need bigger homes after several weeks of growing and will need to be transplanted either into a bigger pot or directly into the ground.
When planting into the ground, make sure not to crowd your plants so their roots don’t run into each other.
The symptoms of a rootbound plant include:
- Flimsy new growth
- Stunted flower production
- Stem discoloration (reddening)
- Nutrient sensitivity
A rootbound plant may also appear under-watered. If a plant requires watering more than once a day, it may need to get transplanted.
When to transplant marijuana
Check out Johanna’s full video series on how to grow weed on Leafly’s YouTube .
Most marijuana plants go through 1-2 transplants during their life but could have more. As an example, transplanting can happen from:
- First container (1-gallon) to second container (2-gallon): 4-8 weeks after seed germination
- Second container (2-gallon) to third container (5-gallon): transplant 8-12 weeks later, or 2 weeks before flowering
Some growers may only transplant once: using the example above, from a 1-gallon to a 5-gallon container, skipping the 2-gallon. And depending on how big you want your weed plants to get, you may transplant into bigger pots than what’s listed above.
The same goes for transplanting outside, in the ground—you can go straight from the first pot into the ground, but it depends on when you transplant and your local climate and weather.
Here are some indicators that your cannabis is ready for a new container.
Number of leaves
Young plants sowed in small containers are usually ready to be transplanted after they’ve sprouted 4-5 sets of leaves, but keep in mind this may vary from strain to strain.
Check the drainage holes at the bottom of the container—a plant should have a healthy and visibly white root system. If roots are growing out of the holes, it’s time to transplant.
Any discoloration or darkening may indicate the plant has become rootbound and a transplant should take place immediately.
End of vegetative stage
A weed plant should be in its final pot or in the ground with plenty of room for its roots before it enters the flowering stage. During flowering, a plant will increase in both size and volume, as the plant itself continues to grow and as buds develop. It will require a substantial amount of space for root development.
How much space does a marijuana plant need?
|Plant height (inches)||Pot size|
|0-6″||4-inch (16 oz.)|
When transplanting cannabis, give the plant at least double the space of its previous container. This reduces the number of times you need to transplant and minimizes the risk of transplant shock, which may occur when a plant experiences extreme stress from root disturbance.
For example, you could go from a 1-gallon to a 2-gallon to a 5-gallon, or from a 2-gallon to a 5-gallon to a 10-gallon.
Medium-sized indoor cannabis plants tend to be fine in 5-gallon containers as a finishing pot. Large outdoor plants may require much bigger containers to reach their behemoth potential, sometimes up to 10- or 20-gallon pots.
When in doubt, always opt for slightly more space than needed. A plant tends to require 2 gallons of soil for every 12 inches of growth it achieves during the vegetative stage. Knowing the potential height of the strain you’re growing is helpful.
Why not start in the largest pot for your marijuana plant?
Growers typically transplant weed plants 1-3 times, moving plants to bigger pots gradually as they get bigger.
If a plant is put in too big of a pot, the roots won’t stretch out that much and won’t soak up as much water. This can cause water to sit in the pot for a long time, waterlogging the plant and leading to root rot.
You can transplant into the largest pot for your weed plant to avoid multiple transplants, but be careful not to water all of the soil—only water around the stalk of the plant where the young roots are.
How to transplant marijuana
Check out Johanna’s full video series on how to grow weed on Leafly’s YouTube .
The process of transplanting weed does not come without risk. Transplant shock can be incredibly detrimental to the growth and development of a cannabis plant, and can even kill it. However, through proper execution, the process of transplanting will benefit the plant and lead to stronger root development and healthier flower production.
First transplant of a cannabis plant
Young cannabis plants should start in a 4-inch or 1-gallon pot. This starting pot should be adequate for a few weeks before transplanting is needed.
Again, the first transplanting should occur after the seedling has sprouted its 4th or 5th set of leaves. To transplant:
- Wash your hands and/or wear gloves to prevent contamination of the delicate roots, and keep the surroundings as sanitary as possible.
- Give the plant a light sprinkling of water to help minimize shock; don’t drench it, as the soil will be difficult to work with.
- Fill the receiving pot with soil, allowing enough space for the new plant.
- Avoid overpacking the soil during and after transplanting—this can compromise drainage and damage the root system.
- Do not disturb or damage the roots when transplanting; the first transplanting poses the greatest risk for shock, which can occur from root damage and agitation.
- Avoid intense light when transplanting; this will help prevent transplant shock as well.
- Fully water in the plant once it’s in its new home.
Additional transplanting of cannabis plants
You may need to transplant your weed plant a second or third time to maximize its growing potential. Always monitor plants for symptoms of distress or overcrowded roots.
To do so, follow the steps above, and make sure the new container is at least twice as big as the old one, if not bigger.
The finishing container is the final home of a plant until it’s harvested. This will be the largest container for a plant, and you always want to transplant into this pot 1-2 weeks before the flowering stage—you don’t want to disturb a plant while it’s flowering.
Keep in mind that large plants may require stakes or other support to avoid structural damage after transplanting.
I have an indoor growroom and in my recent harvest I found seeds in the buds, but I’m sure there are no male plants in the room. I’ve heard that light leakage can cause plants to become hermaphrodites. Is this true, and if so, do you have any tips for avoiding this?
Cannabis plants are monecious. This means they have the ability to be either male or female. Or in the case of hermaphroditism, they can be both. The reason to make sure there are no males or hermaphrodites in your garden is because male flowers make pollen. When pollen touches the white hairs on a flower, it makes a seed, and seeded weed gives you headaches. Even though there are reasons in nature hermaphroditism could be important, such as continuing the species in case there is no male present, hermaphroditism is generally a bad thing when talking about cannabis plants.
Light poisoning is the most common cause for a normal plant to hermaphrodite.
Light poisoning refers to the flowering night cycle of a plant being unnaturally interrupted with light. The best way to prevent this is to close yourself inside your darkened room during the daylight, and then after allowing a few minutes for your eyes to adjust to the dark, check for any light leaks from covered windows, door jams, etc. Also cover all timer and appliance lights with tape.
Negative stressors can combine with small interruptions of the light cycle to cause hermaphroditism, especially with less-stable, clone-only hybridized strains. When the night cycle is abnormally interrupted, it sends a mixed hormonal signal to the plant. This can cause a full female plant to throw some male flowers. Male flowers are easy to identify, especially when side by side with female flowers. Male flowers look like small bunches of bananas, which will take a week or two to swell before they burst and release their pollen.
Finding a hermaphrodite in your growroom can happen at any stage of the flowering cycle and is indicated by the presence of male flowers growing on the same plant as female flowers. As with all species in nature this can occur in varying degrees. A plant can become slightly or majorly hermaphroditic. In cases where singular male flowers are found between the branch and stalk nodes, you should be diligently removing them as they grow. You must re-inspect the plant top to bottom every few days to be sure pollination and seeding doesn’t occur. If you find male flowers (anthers) actually growing from within the female flowers (buds) the situation is a little more dire. You can still remove all the male anatomy as it appears, but it will be harder to find and much more prevalent. This is a horrible discovery that leads to a tough decision: Should you let the plant live and risk the whole crop being ruined by seeds?
In either case, once hermaphroditism has compromised the safety and purity of your sensimilla, the plant should not be propagated further. Remember, once a hermy, always a hermy. The plant pictured here is in the tenth and what should have been the final week of ripening, but a timer failed and one light stayed on continuously for almost two weeks, causing this vegetative regrowth. Because the light was continuous, the plant made no pollen. This method of re-vegging can be used to save a flowering plant you have no copies of, but be careful, as this may cause some strains to hermaphrodite.
Purposefully causing a plant to hermaphrodite is called selfing. Gibberellic acid or colloidal silver is typically sprayed onto the female plant. This technique is used to make feminized seeds and uses the plant’s ability to be both male and female to force a female plant to produce male flowers. The pollen contained in these male flowers can only produce female seeds. Just keep in mind that feminized plants should not be used for breeding, as they were produced without a true male, making them genetically inferior.