Having cared for your cannabis plants throughout the vegetative stage, ensuring they are healthy and have seen impressive growth, it is then time for them to enter the flowering stage. The flowering stage occurs when your cannabis plants receive long hours of uninterrupted darkness. Switching the light cycle to 12 hours of darkness each day will trigger your plants to stop their growth and instead focus their energy on producing buds.
If growing outdoors nature will determine when your plants transition into the flowering stage. This will usually occur towards the end of summer when the days become shorter, therefore providing more darkness for your plants.
The flowering stage is when it begins to get exciting as a grower. Watching your plant develop multiple bud sites and then colas stacked with buds is what every cultivator wants to see. But compared to the vegetative stage, the flowering stage is not as straightforward, you will have to pay close attention to your plant’s needs. But don’t worry, we have everything you need to know about growing weed during the flowering stage, helping you achieve a successful harvest.
How long does flowering last?
The length of flowering time for your plant will usually be around 7-9 weeks. However, some factors may mean the flowering stage will last longer. The main factor will be the strain you are growing. Sativa strains usually always have longer flowering periods than indicas, with some sativa strains taking up to 14 weeks to fully develop. Looking at the strain info when you purchase your seeds will give you some idea of how long to expect.
Stages of Flowering
Here is a breakdown of what to expect during the weeks your cannabis plant is in its flowering stage. As stated earlier the flowering length of a plant will depend on the strain you are growing, so it is difficult to give exact time frames, however here is a rough guide of what to expect during your plant’s flowering stage.
Initial few weeks
The first few weeks of flowering are where you will see the most growth. As your plant transitions from vegging to flowering, it will continue to grow, this initial time can be known as the stretch phase. This is caused by your plant preparing itself to become loaded with heavy buds, and stretching to gain as much light exposure as possible.
While your plant is putting in lots of effort to gain size and height, she will grow several new leaves, mostly at the top of the main colas. Your cannabis plant will be busy growing many additional fan leaves, and the stem will thicken so it can become stronger and sturdier.
These first 3 weeks are likely to be the most important part of the growing process. Therefore to ensure you obtain the highest yields you must take great care of your plant during these weeks.
These early weeks are also a perfect time to begin LST (low-stress training) on your plants. This will allow you to bend and manipulate the plant to increase light penetration to all areas of the plant, therefore increasing bud sites.
After a few weeks in the flowering stage, you will likely be able to start noticing white pistils, these fine white hairs will develop at locations where the big fan leaves meet the main stem. It is these pistils that will later become buds. These white pistils will only appear on female plants capable of producing buds. If you have any male plants then they will display small pollen sacs instead. If you are only looking to grow feminized plants that will flower, then you need to discard any plants that look to be male. Without being removed they will pollinate the female plants and cause them to grow seeds, which you definitely don’t want to happen.
During the first 2 weeks of flowering, you need to also think about the nutrients you are feeding your plant. Although it will now require nutrients more specified for its flowering stage, it is recommended you slowly incorporate them.
By the third week, the stretching will begin to stop. The stretch phase will most likely have resulted in your plants being 40-50% bigger than they were when they began the flowering stage.
By around weeks, 3-4 is when your cannabis plant will start to develop its first buds. The vegetative phase is completely over, and your plant will most likely have stopped growing and is now spending all its energy on growing buds. During this period, your plant must get enough light and plenty of water/nutrients. Your cannabis plant will become very sensitive to its environment, therefore try to keep the environment stable. Avoid nutrient burn and over-watering at all costs.
By week 5 you will begin to observe your buds becoming thicker, and may even notice some additional buds growing. All your plant’s focus now will be on fattening its buds. As the buds become weightier it is a good idea to try and reinforce the branches by tying them with string to something that can help them support the additional weight and stop them from snapping.
You may also want to start gently defoliating your plant during these weeks. The process of defoliation is the removal of fan leaves to allow more light to penetrate the bud sites. This can greatly aid in developing the size of the buds.
As the buds are growing bigger the smell will become much more pronounced. It is a good idea to make sure you have good ventilation if growing indoors. The strong aroma of marijuana can cause a big problem for some growers, especially if growing in a region where cultivating weed is not legal. So it is always a good idea to make sure you reduce the smell as much as possible.
7 Weeks and Beyond
By this point, all of your plant’s energy will be directed toward ripening its buds. You will notice that the pistils will have changed to an orange/brownish color. This is a sign that the plant is getting closer to harvest time. You may also begin to notice some of your plants’ lower leaves turn yellow and even drop off. This is completely normal and is merely a sign that your plant is funneling all of its energy to the buds.
Although your cannabis plant is nearing the end of its life cycle these last few weeks are critical, and still require a lot of dedication and care. Therefore make sure you are keeping Ph levels consistent and nutrients stable. If you continue with care, then you will be well on your way to ensuring that you will harvest the best possible quality and yield of weed.
Other than fast flowering strains it is very unlikely that your cannabis plant will be ready to harvest before the 8-week mark. Usually, you will be looking at 9 weeks and beyond, so do not be impatient and just allow the plant to do its thing.
The closer to harvest you get, you might notice lots of yellowing leaves. This is normal and you should not adjust anything to counter it. This is the only point during cannabis growing that yellowing leaves are acceptable.
Many growers choose to do a complete flush of the plant for a week or 2 before harvest, to remove any salts and minerals in the soil. When you “flush,” you stop administering nutrients and give the plant only plain, pH-balanced water in these final weeks. This does not increase yields but increases the quality of the bud.
After weeks of caring for your cannabis plants, the time will finally come to harvest those fat buds. Make sure you time your harvest correctly. Looking at the trichomes through a jeweler’s loupe or a small microscope to check your plants’ trichomes is the best way to know when to harvest. You can observe whether the trichomes turn from clear to a milky white color. If a lot of the trichomes you see are still clear and transparent, it means it’s still too early for harvest. But when most of the trichomes have an amber color this means that the THC content of the buds is at its maximum, and the plant is ready for harvest. Check out our full guide on harvesting your weed plant for more information.
Once you have harvested your buds it will then be time to begin the drying and curing process.
Maintaining a Healthy Plant Through Flowering
To ensure you navigate the flowering stage as well as possible, ending up with a bountiful harvest, here are a few tips to help you get the best results.
Lights can make the difference between an average grow and an amazing one. Light is what plants love to grow as big as possible, so investing in good quality lights will help you greatly increase yields. Make sure you have sufficient, strong light coverage for your entire grow space, with light that provides sufficient lumens to your plants. Grow lights can be expensive, but it is definitely worth the extra investment.
Light Colors For Flowering
Cannabis plants like red and orange wavelengths during flowering (between 580–700nm) to encourage the ripening of their flowers. For best results, use a grow light with this spectrum during the bloom phase.
Amazon has some great lights available
Depending on the size of your grow space, you need to consider how many plants you will grow. Allowing plants enough space to grow both in height and width. Spacing your plants out is important as it will allow light to penetrate all the plants sufficiently. If too many plants are crammed in too small a space then you will end up blocking the light that many bud sites will need to thrive.
P and K Nutrients
Potassium and Phosphorus are the two most important nutrients necessary for a successful flowering phase. Plants crave them, therefore if you want some big buds at the end, make sure you feed them some fertilizers and supplements that are rich in P and K.
Check for Mold, Pests, and Diseases
Some things can destroy all of the hard work you have put into nurturing your cannabis plant. Constantly check your plant for any sign of mold, and if discovered make sure you remove it as quickly as possible. Mold spreads fast and can completely overtake your plant.
As with mold, it is always worth keeping an eye out for any pests that may have infiltrated your grow. Pests can be very difficult to get rid of once they are on your plant as they are mobile and quickly reproduce.
Plant diseases can happen nearly anywhere and at any stage of the plant’s life cycle if there are environmental imbalances. Diseases can be either fungal or bacterial in origin, though providing a balanced environment to prevent disease is the best solution in both cases. Look out for any leaf discoloration and other oddities on your plant and take action if discovered.
And as Always
Make sure you keep an eye on the fundamental points of the growth. Always remember to water the plants correctly. Overwatering and underwatering your plants can have serious effects on their health.
Always keep an eye on the nutrients you are feeding your girls. Getting the right balance is important, you do not want to give excessive nutrients and cause nute burn. You also do not want your plant to have any nutrient deficiencies.
Maintaining proper temperature, humidity, and Ph levels while your plant is flowering will mean you get the best results possible. So use a thermometer to keep a check on the temps in your grow space, a hygrometer to make sure your humidity levels are around 45%, and a pH meter designed for soil sampling (the best range for growing cannabis is between 5.5 to 6.3) will help you keep on top of everything.
The flowering stage of growing cannabis can be a challenging one. Cannabis plants are sensitive and any stress or slip-ups during the flowering stage can affect the overall yield of your harvest. But using the information in this article will give you a great chance to harvest a plentiful supply of amazing buds. And remember that these things take time and experience to perfect, so perseverance is key.