When producing cannabis plants, one of the most crucial moments is the transition from the vegetative to the flowering stage. As it enters the final phase before harvest, your cannabis plant will make all of the necessary preparations to provide you with the most bud possible. As a result, it is critical that your plants make the shift smoothly (and at the appropriate time). Plants generally accomplish this on their own, but indoor growers must assist them along the route. There are numerous aspects that influence when and how you should do it, all of which demand serious attention. This guide is designed to make things easier.
Like all living beings, marijuana plants progress through a variety of phases throughout their life cycle. The process begins with germination, in which the seed sprouts and grows into a little seedling. As the seedling matures, it enters the vegetative stage, distinguished by rapid growth and the formation of leaves, branches, and a robust root system. The cannabis plant enters the flowering stage after a set duration, determined by the plant’s genetics and environmental variables. This is when the marijuana plant spends its efforts producing blooms that are high in cannabinoids and terpenes.
Identifying day and night intervals is crucial during the weed flowering phase. Growers frequently use a lighting schedule of 12 hours of continuous darkness followed by 12 hours of light. These light cycles mimic seasonal fluctuations in natural sunshine, deceiving the plant into entering the flowering stage. It’s important to remember that any light loss during the dark time can cause the marijuana plant to revert to the vegetative stage or produce less output.
Photoperiodism is a plant’s response to the lengths of day and night (light and darkness). Photoperiodism is important in cannabis because it determines when the plant transforms from the vegetative to the blooming stage. Most cannabis cultivars are classified as short-day plants, which means they require extended dark periods to begin flowering.
When the hours of darkness exceed a specific threshold, usually about 12 hours, the cannabis plant begins generating flowering hormones, which eventually lead to bud production.
When the light cycle gives your cannabis plants more hours of uninterrupted darkness, they enter the blooming stage. Your plants will stop developing and focus their energy on generating buds (flowers). Outdoors, this typically occurs as the days shorten toward the end of the summer. When you grow indoors, flowering begins when you turn off the lights for 10-12 hours. The flowering phase for most cannabis strains lasts between 7-9 weeks, while some Sativa take even longer to mature.
Indoor cannabis farmers may control when the plant begins the blooming stage by switching to a 12/12 light cycle. There are several considerations to make when selecting when to do this. Growers usually let their plants veg for around 60 days before they begin flowering. This allows plants to grow to a suitable size without becoming excessively huge. In principle, if you had enough space and strong enough lighting, you could maintain vegging a plant and allow it to grow quite huge, resulting in a very high overall yield (per plant). However, producing more, smaller plants generally result in a higher yield per square meter.
Making the transition from veg to flowering too early can result in a low yield. Likewise, flipping your marijuana too late will result in scorched buds or overgrowth. There are several aspects to consider while attempting to flip your marijuana. These considerations include the plant’s age, the maximum height achievable in your setup, the cannabis strain, the plant’s origin, and the growing method employed. It is critical to understand the importance that each of these components has in determining the end outcome when flipping. It is also vital for every producer to recognize the uniqueness of each crop while examining these elements.
The amount of space provided in your growth environment is the most critical thing to consider. This is because this aspect is unique to the producer, and each grower should make judgments based on it. Plants that stay in the vegetative stage for an extended period grow higher. As a result, if your setup space is limited, you must flip the plants as soon as possible. This is to guarantee that the plants do not outgrow their surroundings before flowering. Plants that grow too tall in such settings are severely damaged and may be burned or fried.
Many farmers underestimate the age of the plant, even though they should not. Some have even claimed that the plant’s age is irrelevant. It is commonly believed that plants cultivated from seeds mature in 60 days, although this is not the case. Young seedlings cannot flower adequately for about two to three weeks, so the plant’s age must be considered. Plants should be in the vegetative stage for about 60 days to maximize output. This permits the plant to grow correctly and minimizes mistakes. However, flowering can be completed earlier if the growing conditions do not allow for this 60-day period.
Indica and Sativa marijuana strains have distinct characteristics that must be addressed when flipping cannabis. The changes are less evident during the vegetative stage than during the flowering phase. Indica cannabis strains are better suited for producing short, thick, and bushy plants. Conversely, Sativa stains are longer, thinner, and increase faster throughout the blooming cycle. Sativa strains can also develop up to double their height during the blooming stage, which lasts until harvest. In addition, hybrid cannabis strains include the traits of both parents, making it difficult to classify them as Indica or Sativa. When working with hybrid cannabis strains, it is critical to research the strain’s parent to determine how to grow it most effectively. When dealing with hybrid strains, the rule of thumb is that they will grow twice as tall in a vegetative condition.
The growing method used affects the time it takes to transition from the vegetative to the flowering stage. The blossoming time varies depending on the method used. The Sea of Green (SOG) approach, which is commonly used on Indica strains, ensures that flipping occurs early. Plants cultivated in SOG can blossom when they reach a 15-30cm height. The screen of green (ScrOG) approach requires placing a mesh 30 to 60 cm above the plant’s base. This strategy requires plants to remain vegetative for several weeks before blossoming. The lollipopping technique eliminates the plant’s lower growths to ensure that available nutrients reach those needing them. Sativa can flower at 30 to 45cm, whereas Indica can reach 100cm.
The origin of the marijuana plant is significant when selecting whether to transition from vegetative to blooming. A robust root system is necessary to avoid problems during the flowering period, which is why the plant’s source is vital. Clones tend to grow quite large, which may cause the grower to flip early due to size. However, before flipping these clones, producers must guarantee that they have a strong root system. Conversely, seedlings can be flipped early, but it takes 2 to 3 weeks.
The role of darkness in cannabis flowering is to trigger the production and release of flowering hormones, such as gibberellins and cytokinins, which regulate the transition to the flowering stage. These hormones initiate bud formation and the synthesis of terpenes and cannabinoids. The 12/12 light cycle is the most widely used light cycle for flowering cannabis. It means providing 12 hours of light followed by 12 hours of uninterrupted darkness. This closely mimics the natural light circumstances in late summer and early fall, signaling the weed plants to initiate flowering.
The light spectrum is also very important for cannabis plant development. Different wavelengths of light have different effects on the plant’s growth, photosynthesis, and flowering. The optimal light spectrum for cannabis growth varies depending on the stage of the plant. During the flowering stage, a spectrum with a higher proportion of red light (600-700 nm) and far-red light (700-800 nm) stimulates bud formation, resin production, and cannabinoid synthesis, leading to higher potency and flower quality.
The transition from the vegetative to flowering phase must be done at the appropriate time. Most seeds will tell you how many days the plant should be in the vegetative stage. Similarly, the seeds will typically indicate how long the plant will be in the flowering phase. Keep in mind that the vegetative stage lasts two to four weeks, depending on the cannabis variety of cannabis you are growing. You want the plant to have a robust root system before flowering so that it can maintain itself.
Indoors, you should also consider the size of the bucket you’re growing in. A week per gallon should suffice, as you don’t want to start flowering too soon. The ability to grow outside allows nature to trigger blossoming in your plants naturally. The vegetative stage for outdoor grows must be planted at the appropriate time of year. Planting seeds in the summer allows for natural light, ensuring that you harvest around October.
The Cannabis plant requires the following nutrients to grow: nitrogen (N), phosphorus (P), and potassium (K). When the plant begins to bloom, the concentrations of P and K must be gradually raised while N concentrations are reduced. That is why there are fertilizers explicitly designed for vegetative development and flowering. Additional secondary nutrients will be required for the plant’s proper development. These include magnesium (Mg), calcium (Ca), and sulfur (S). Furthermore, micronutrients are required but at a low concentration. These include zinc (Zn), chlorine (Cl), manganese (Mn), iron (Fe), cobalt (Co), copper (Cu), molybdenum (Mb), boron (B), and silicon.
So, what is your plant’s ideal feeding strategy or nutrient application schedule? That is up to the grower, but keep in mind that you will need to give these nutrients by foliar, liquid, or solid fertilizers. Even when growing organically, simply placing your cannabis in plain soil is typically insufficient for the plant to generate healthy, fat buds. Several fertilizer brands provide kits prepared for each stage containing the required nutrients. Begin with the manufacturer’s recommended dose, or even 1/2 lower, to avoid saturation, and slowly increase the doses until the desired results are reached. Proper nutrition management is required for optimal plant growth and bud production during the flowering stage. It’s essential to keep the following in mind:
Cannabis flowering plants demand different humidity and temperature conditions than vegetative plants. Rather than adjusting the temperature, humidity, and light cycle all at once, experts suggest gradually altering the temperature and humidity over two days, allowing your plants to adapt to these adjustments by leaving them in the vegetative stage for a few extra days before flipping the lights.
Marijuana plants in the flowering phase thrive in temperatures ranging from 18° to 26°C. Temperatures below this range may harm or kill the cannabis plant if it is exposed to freezing temperatures for an extended time. Temperatures below 17°C may impede plant growth, while extremely low temperatures (below 2 °C) may permanently destroy the plant. However, extreme temperatures have a harmful impact on the plant. Temperatures above 28°C can cause stunted growth, scorched leaves, excessive water evaporation, excessive dryness, and other issues.
In addition to keeping temperatures within the “warm” levels, controlling relative humidity in the growth environment is critical. The relative humidity of the air is given as a percentage. At this stage, humidity should be kept between 40 and 50%. Mold and fungi can grow in high humidity conditions.
Flowering marijuana plants indoors is the most exciting moment for a home grower who has patiently seen their plants mature into vegetative conditions and are now ready to flower. It is also during this time that many things can go wrong; therefore, here are some typical mistakes to avoid as a new grower while switching cannabis plants.
This is another reason why numerous growers struggle with mold and mildew, often at the same time. When combined with inadequate air circulation and high temperatures, a humidity level of much beyond 40% can have catastrophic implications, mainly when growing a strain known for developing thick, dense, and big buds. During the flowering season, keep the relative humidity as low as possible, ideally between 35 and 40%. Some growers put a dehumidifier in their grow room to assist in reducing moisture in the air and maintaining a constant atmosphere.
Cannabis plants require a daylight temperature of roughly 24 degrees Celsius, with a drop in the lights off temperature to about 18 degrees Celsius. As a beginner, allowing your grow room temperature to get above 25-30 degrees Celsius might be problematic, as it is directly associated with relative humidity levels and air flow. You will also see that the healthy shine and developing structure start to suffer from heat stress, which affects transpiration. Over time, the weed leaves will become dry and brittle, and the plants struggle to absorb nutrients effectively, resulting in various nutritional concerns.
This is a simple mistake that, depending on how late in the flowering cycle you are, can have serious consequences. When a growing media becomes oversaturated, the roots become waterlogged and require time to dry out. Overwatering your plants not only slows down their ability to absorb nutrients and photosynthesize but also allows anaerobic bacteria that thrive in low-oxygen environments to infect the roots. The general rule when using an organic soil medium is to feed 10% of the pot’s weight in liters. As the growing medium dries out, a 10-liter pot requires only 1 liter of water or nutritional solution.
A decent-quality grow room will have many oscillating fans that turn at different times and heights. The idea is to have a continual fresh air current moving around the pots’ base pots, the middle of the canopy, and the region over the plants and grow light tops. If you are currently using one or two modest fans, it is an excellent plan to add another and ensure they all blow at different heights 24 hours a day. Poor air movement is the leading cause of plant disease entry into the garden, such as powdery mildew or botrytis. Pests like spider mites love a warm, humid, and stagnant air environment. Therefore, the more airflow you can supply your plants, the more CO2 can circulate, and the chance of mold or a heavy mildew infection decreases significantly.
The final mistake to avoid is nutrient toxicity, which occurs when plants have an excessive amount of N, P, or K and show apparent indications. One of the worst things that may happen when a marijuana plant is exposed to excessive amounts of K is that the leaf structure degrades and becomes mushy. Combined with a dead rotting odor, bringing plants back from this point can be difficult, leaving a novice or expert gardener wholly deflated. When dealing with toxicity when growing Cannabis, the best course of action is to simply feed plain water until the imbalance has been internally corrected and the plants can develop normally again 5-7 days later.
During the flowering stage of cannabis plants, it’s crucial to be vigilant about pests and diseases that can impact their health and yield. Common pests and diseases during flowering include:
Keeping your weed plants healthy and pest-free during the flowering stage is essential for a great harvest.
Here are some ways to prevent and manage pest and diseases:
Indoor growers can control the light cycle to manipulate the growth and flowering stages of cannabis plants. Typically, outdoor producers let their plants flower independently by relying on the natural change in daylight hours in their cannabis plants. This commonly happens after mid-summer, when the days are shorter than 12 hours. Outdoor producers should ensure that their plants do not receive light at night. This includes light sources, including garden lights, streetlights, and spotlights. However, outside cannabis plants do not always have to be left to their own devices.
A change in environment might cause them to blossom, just like indoor plants. Some climates simply don’t allow plants enough time to blossom before winter. In other climates, a grower may need to force flowering to keep the plant under control. Furthermore, some producers opt to force blooming to harvest numerous crops in the same season. Regardless of the reason, forcing outdoor plants to flower is a straightforward procedure. Outdoor farmers frequently force flowering by covering their plants and restricting their exposure to sunlight. Cultivators employing greenhouses only need to cover their grow room’s windows.
Some signs of a healthy transition to the flowering stage are:
These signs can vary depending on the strain, the environment, and the plant’s light cycle. Generally, cannabis plants will start showing signs of flowering after 1-3 weeks of switching to a 12/12 light cycle (12 hours of light and 12 hours of darkness per day) or when the natural daylight hours get shorter in outdoor grows.
Here are some troubleshooting tips and remedies to help your cannabis plants get back on track and produce gorgeous buds.
If your plants aren’t flowering, it could be because they are too young. Allow your plants extra time to develop and mature before flowering. Be patient and keep track of their growth, ensuring they get the care and nutrients they need at this period.
Verify the sex of your weed plants to confirm that you are dealing with female plants. If you find any male plants, destroy them right once to prevent pollination and the production of seeds. Check your plants for evidence of sex, such as pollen sacs in males and little white hairs (pistils) in females.
Inspect your grow area for any sources of light leakage that could be disrupting the dark time. Cover windows, cover any holes or crevices in your grow chamber, and ensure that no surrounding equipment or external lighting interferes with the necessary darkness for flowering. Complete darkness at the optimum time is critical for starting and maintaining the blossoming process.
Ensure your cannabis plants receive the proper light spectrum for each growth stage. During the flowering stage, change your grow lights to produce a higher proportion of red light to encourage bud development. LED grow lights with customizable spectrums are great for producing the precise wavelengths required for maximum flowering.
Change your time if your weed plants are not getting the proper light cycle. Indoor gardeners should ensure their plants get 12 hours of uninterrupted darkness daily during the flowering phase. Use a timer to automate this process and avoid unintentional exposure to light during the dark period. Outdoor producers can use the natural decrease in daylight hours as the seasons change to stimulate flowering.
Check and modify your nutrient solution regularly to ensure it contains the nutrients required for flowering. Increase bloom nutrients, such as phosphorus and potassium, to aid in the formation of thick buds. Avoid high nitrogen levels, which can stimulate vegetative growth at the price of flowering. Conduct regular soil or water tests to ensure that your weed plants are getting the right amount of nutrients.
Maintain ideal environmental conditions in your grow room to encourage healthy flowering. Monitor and manage temperature and humidity levels to ensure they remain within acceptable limits. Adequate airflow and ventilation will help to avoid stagnant air and lower the danger of pests and infections. Inspect your weed plants regularly for stress indicators or environmental difficulties, and deal with them immediately.
In some circumstances, modest stress can help your plants shift to flowering. Low-stress training (LST), defoliation, fluxing, and pruning are all methods for redirecting energy toward bud formation. However, you should be cautious and avoid subjecting your plants to severe stress, as this can negatively impact their health and output.
Ensure your growing medium has appropriate drainage and aeration to avoid soggy roots and nutritional imbalances. Overwatering or underwatering can impede plant growth and flowering. To avoid extremes, set a regular watering schedule based on your plant’ demands and monitor moisture levels in the growing media.
Genetics have a significant impact on the flowering properties of cannabis plants. Some strains might have longer or shorter flowering periods, and specific phenotypes within a strain may exhibit different blooming behaviors. If you’ve tried all the troubleshooting approaches and your plants still don’t flower, it’s time to look into the genetics and try different strains.
Finally, keep in mind that producing cannabis takes time and effort. Every growth experience is a learning opportunity, and it may take some time and experimentation to obtain the desired outcomes. Maintain your vigilance, adjust your strategies as needed, and continue to improve your cultivating abilities over time.
Cultivating cannabis organically can lead to healthier plants and better yields. Here are some organic methods to enhance flowering in your cannabis plants:
Pruning is a technique that involves cutting off parts of the weed plant to improve its growth, health, and yield. Pruning weed plants during flowering stage should be performed carefully and only for specific purposes. Here are some tips and benefits of pruning cannabis plants in the flowering phase:
Monitoring the color and cloudiness of the trichomes can help you calculate the best harvest window since different strains and intended effects may require somewhat different times. Selecting the best time to harvest your cannabis buds is critical for optimizing potency, flavor, and overall quality. The optimal harvest window depends on various factors:
The method you use to harvest your cannabis plants varies depending on whether you’re a commercial producer or a hobbyist. Here are some ways to consider.
The cannabis flowering phase is an essential stage in the plant’s life cycle. Understanding each step and the specific obstacles that may develop during the flowering process is critical for any grower, whether a hobbyist or a commercial planter. Mastering blooming cannabis may help assure plant health and success, resulting in a plentiful harvest.
Remo “Urban Remo” Colasanti is world-renowned for his growing skills, and over the past two decades he has helped thousands of people learn how to achieve their garden’s maximum growth potential. He has created a complete system of vitamins, minerals, and extracts – everything your plants need and nothing they don’t. As well as offering Remo Nutrients, Urban Remo also has a whole lot of knowledge in his head that can definitely benefit growers of all levels. Get the chance to learn from the legend himself in the articles below.