How to Plant Cannabis Seeds Indoors
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Growing cannabis at home can be a fun project and a nice way to have your own cannabis plants on hand. You may want to grow cannabis indoors due to inclement weather in your area or due to a lack of green space in your yard. Start by germinating the seeds. Then, plant the seeds in soil or in a starter cube. Once the seeds have been planted, care for them properly so they grow and thrive.
- After 12 hours, place the viable seeds on a towel.
Wet one paper towel and put it on a plate. Paper towels are thick enough to retain the moisture needed to help the seeds germinate. Place one paper towel under running water until it is wet to the touch, but not dripping wet. Use a ceramic dish or plate, as it will be strong enough to hold the towels and the seeds. The paper towel should cover the dish or plate.  X Research source
- If you do not have enough space on one plate for all your seeds, soak two more paper towels and put the remainder on a new plate covered in a wet paper towel.
Wet other paper towel and place it over the seeds. Make sure the wet towel makes contact with the seeds.  X Research source
- You can try using a heat lamp near the seeds to keep them warm. Do not warm the seeds up too much, as you do not want your heat source to dry out the paper towels.
- If the seeds become too dry, they could die and never germinate.
- Be very careful with the seeds as they open. Avoid prodding, pulling, or touching the seeds, as you do not want to damage the roots.
- Any seeds that have not opened and grown roots within a few days should be discarded, as they are not viable.
- As an alternative to soil, you can use starter cubes from your local nursery or online. Starter cubes are pre-cut growing pods made of composted bark. They contain a hole where you can place the cannabis seeds and grow them in good conditions. Basic starter cubes are inexpensive and easy to use.  X Research source
- If you make planting holes that are too shallow, the seed’s roots will not have enough soil to grow well. If you make the planting holes too deep, the seed will have a difficult time sprouting.
- Do not pull or tug at the seeds when you pick them up with tweezers. If they are stuck to the paper towel, wet the towel with water to make the seeds easier to pick up.
- Do not press hard on the seeds when you cover them, as this can disturb their growth.
- If you are using starter cubes, pinch the top of the holes in the cubes closed.
- Maintain a growing temperature of 75 to 85 °F (24 to 29 °C) for the plants so they thrive.
- Stick to a regular watering schedule so the plants get enough moisture. You can plan to spray the plants in the morning and then again at night so they get the water they need.
- Grow lights range from $200 to $1,200 USD depending on the size and model.
- You can get cool white grow lights at your local hardware store or online.
Avoid touching or handling the seeds as they grow. Touching or handling the seeds can damage them and stunt their growth. With the right growing conditions and care, your seeds should sprout and poke out of the soil within five to ten days.  X Research source
More than 12 hours of light a day for about 4-6 weeks as the plant matures will be enough. Once the plant is a decent size, you may induce flowering. Switch the plant to a timer of EXACTLY 12 hours of strong light (the more sunlight the plant gets, the more energy it can devote to flowering).
Yes, it is bad for the plant to have water constantly sitting at the bottom of the pot. It could make the roots rot over time.
You can actually find LED lamps made for growing plants online. If you don’t want to bother with that, you can just get a purple light to grow them under. There are many articles online talking about the effects of colored lights on plants.
If you plan on growing short, fat plants, they should be at least 6′ apart. You don’t want the plants rubbing on each other or shading the other plants. You will also want to select a spot to ensure all plants will receive maximum sunlight.
You can start as soon as you see two little leaves budding. During that time, make sure to use distilled water when watering them.
Cannabis thrives in a comfortable room temperature when grown indoors, or a little warmer – not too dry, not too humid. If it feels too hot or too cold for you, it’s probably too hot or too cold for your cannabis plants.
You can’t. You can try keeping it by a window, but you still won’t have much success. Lights aren’t that expensive, look on Amazon.
Yes, rain water is fine for any plant. The use of distilled water is to keep from adding tap water contaminants.
Keeping the plant from “stretching” is simple. Place the lights closer to the top of the plants. There are good video examples on YouTube showing two seeds started at the same time and placed under lights at different heights. The plant with inadequate lighting actually “reaches” for the light, growing tall and thin with longer internodal gaps. The seedling with closer light grows short and squat, with less stem between leaves (internodal distance), which means a better frame and plant structure for supporting the massive buds that you want to grow. As the plant grows, raise the lights with it. (Most folks suggest somewhere in the 16-30 inch range from source to canopy.)
The cultivation of cannabis is considered illegal in many jurisdictions. Make sure it is legal to grow cannabis in your area.
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About This Article
This article was co-authored by wikiHow Staff. Our trained team of editors and researchers validate articles for accuracy and comprehensiveness. wikiHow’s Content Management Team carefully monitors the work from our editorial staff to ensure that each article is backed by trusted research and meets our high quality standards. This article has been viewed 1,327,010 times.
To plant cannabis seeds indoors, first soak the seeds in lukewarm tap water for 12 hours. Discard any seeds that float to the top. Then, place the seeds on a damp paper towel on a plate with 1 inch (2.5 cm) of space between each seed. Cover the seeds with another damp paper towel. Keep the seeds in a spot that remains between 70-80°F (21-27°C), and spray the paper towels with water whenever they start to dry out. The seeds will sprout in 2-3 days. When they do, fill pots or a growing tray 3/4 of the way with loose potting soil that has a pH between 5.8 and 6.3. Press the soil down lightly, leaving some air in it. Then, use a pencil to poke 1 inch (2.5 cm) holes in the soil. Place the sprouted seeds vertically in the holes and fill the holes with potting soil. Water the soil thoroughly and place the pots or tray in a spot that’s always 75°F (24°C) or warmer. Set up a grow light over the seeds and leave it on at all times. Water the seeds every day so the soil doesn’t dry out. The seedlings will emerge in 2-4 weeks. To learn how to use cool white grow lights to help your cannabis seeds grow, keep reading!
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Winter marijuana seeds: features and tips for a perfect harvest.
As the cold season approaches, cannabis growers tend to wonder what the winter marijuana seeds are, so they have a fair chance of harvesting them during the winter as well.
It is said that auto flower seeds are best for outdoor winter, as they have – at least partially – Ruderalis genetics. And Ruderalis cannabis reflects what the name makes us imagine: it is ‘rough’, wild, used to survive even under extreme conditions such as cold, rain and high humidity.
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The belief that auto flower seeds are perfect for withstanding extreme temperatures and weather conditions is not entirely wrong, but the farmer’s final goals must also be considered. Are you only interested in a strong cannabis plants or are you looking for a good harvest? If the latter option is the right one, maybe you should not grow outdoors.
Please note that our in-depth studies are only for information. We do not advise you to grow weed seeds because, if you are in the UK, you will commit an administrative or criminal offence depending on the situation. If you currently live in a state where it is allowed to grow marijuana for personal use, then you can rest assured.
Do winter cannabis seeds have a good yield when grown outdoors?
The answer to this question is no! Marijuana plants need special conditions to develop and flourish at their best.
Although automatic cannabis strains flower not according to temperature and light conditions but according to their age (they are usually ready for harvest about 10 or 11 weeks after germination). If grown outdoors in the middle of winter they may still die or stop growing. At best, they may produce very few flowers with low THC and CBD content.
Now imagine you are a cannabis grower. After you have put all your energy into getting a beautiful plantation, winter comes to stop everything: no crops and seedlings irreparably damaged. It’s certainly not a pleasant prospect!
Growing marijuana seeds on winter is undoubtedly possible, but not outdoors. For marijuana plants to develop outdoors in the best possible way, they need favourable climatic conditions.
The perfect conditions for cannabis plants development
Marijuana doesn’t care whether it’s summer or winter. It is only essential to have the right climatic conditions for its growth. For auto flower seeds, fast growing weed seeds and feminized seeds to germinate and for the seedlings to grow well, it is essential that the following conditions are met:
- Relative humidity: during germination, the RH should be between 60% and 80%, during the vegetative phase the RH should be between 50 and 70% and during flowering between 40 and 60% at most.
- Temperature: the temperature should be reasonably stable, so a wide temperature range is not recommended. During the germination of cannabis seeds, the temperatures should be between 22 and 26ºC, during the vegetative phase between 21 and 29ºC and during flowering between 18 and 26ºC. The minimum values refer to night-time temperatures, which should not exceed 6-7ºC difference from daytime temperatures.
- A good soil, well-drained, fertile and fertilized with organic nutrients.
Read the following article to learn more: How to sow marijuana in the best possible soil: 5 things you don’t know about the relationship between soil and germination.
That said, minimum temperatures should never drop below 15ºC as cannabis plants could suffer so much, stop growing and/or die. As you can imagine, it is complicated for temperatures not to fall below 15ºC in winter (unless you are in the Maldives, Hawaii or somewhere else where it is hot all year round… So I envy you!).
Besides, it is not uncommon for rainfall, frost and other situations to occur during the winter months. They will be the perfect conditions for mould and fungi development, which are very harmful to cannabis plants.
That is why growers who choose to plant cannabis seeds in winter do so Indoor or in Greenhouse.
Do winter marijuana seeds exist?
Let’s say that plants born from auto-flowering cannabis seeds and fast growing cannabis seeds are more resistant to low temperatures than seasonal plants. They come from Cannabis Ruderalis varieties crossed with Indica or Sativa. But don’t expect them to resist frost and extreme temperatures!
They may not die below 15ºC, but they will still suffer, either by stopping growing or at most producing a small number of flowers. That’s why growers prefer to grow Indoor or Greenhouse with controlled temperatures, in order not to stop during the winter season and get a good harvest.
Alternatively, if they are in a region with an extremely favourable climate, they can grow in pots and then you only have to shelter them during the evening, at night, and when the weather conditions turn bad.
Since we’ve talked so much about auto-flowering varieties, you might want to add these seeds to your collection… Then visit our catalogue and buy the best weed Seeds BSF, autoflowering, feminized and fast growing weed seeds!
How to Grow Cannabis in Winter
If you think that growing cannabis in a European winter is impossible, then you’ve been misinformed. With the right conditions in an indoor growing operation, you can successfully yield good quality cannabis. We are here to teach you how to set up and optimize your grow room in the winter time.
When growing cannabis in winter, even an indoor garden is at the mercy of the elements. Cold, dry air and dropping temperatures can create problems with relative humidity and light intensity. But that doesn’t mean that growing in winter is impossible. Actually, with the right conditions, an indoor garden can perform just as well in winter as it does in the summertime.
It is true that growing in the winter takes a little more attention and a little more TLC. With the right advice and the right frame of mind, you can successfully grow all year round. That is what we are here to help you do!
How to maintain grow room temperature in winter
Temperature is one of the most important concerns when growing in the winter. Optimal daytime temperature for cannabis is 24-30°C (75-86°F), and optimal night-time temperatures falling in the range of 18-22°C (64-72°F).
As a grower, you want to avoid temperatures outside of the prescribed range but you also want to avoid huge discrepancies between day and night temperatures. Growth rate is severely affected by inconsistent temperature changes as much as by an incorrect temperature bracket.
As well as this, if there is too great a discrepancy between daytime and night-time temperatures in the first 2-3 weeks of the flowering period (during which time plants ‘stretch’ noticeably), very widely-spaced internodes will result. Conversely, keeping the discrepancy as small as possible throughout this time reduces the space between nodes.
A temperature gap of 2-4°C (3.6-7.2°F) is ideal for the first 2-3 weeks of flowering. A gap of no more than 10°C (18°F) should be maintained for the rest of the flowering period.
If you are an old-school cannabis grower, then you probably love growing in the winter. That is because last decade’s HID (high-intensity discharge lightning) technology emits alot of heat. And if you are using them in the summer time, then you need to pay through the roof for air conditioning. But in winter, HID lights can keep your grow room at the optimal temperature.
With that being said, a temperature drop when the lights are turned off is something to think about. To mitigate this, winter growers use their lights during the night time and use daytime as the lights off period. This lets a grower take advantage of warmer temperatures during the day.
While daytime temperatures are higher, they are not always high enough to maintain the plants’ required ‘night-time’ temperatures of 18-22°C (64-72°F). If temperature is consistently dropping below this range when lights are off, it is advisable to use central heating or an electric heater to maintain adequate temperatures.
A digital thermostat will come in handy here to automatically control the heater according to the ambient temperature. If using cold lights such as LEDs, heaters may be required round-the-clock.
Controlling humidity of cannabis grown in winter
Mould is one of the biggest threats to your cannabis garden during the winter. In the winter, there is a tendency for low temperatures to increase relative humidity (RH) to a point of danger for your plants. Not only do cannabis plants detest high levels of relative humidity, but it also makes them a breeding ground for mould and fungi. Low temperatures can create issues in maintaining relative humidity.
Essentially, the volume of water in the air continues to condense as the temperature drops. And if you have ever grown cannabis before, you know that this can open up a proverbial can of worms (or better yet, mould) all of your plants.
The obvious way out of this problem is to keep temperatures at the optimum level, whether by using lights or by using central heating. If the problem is extremely hard to contain, then it may be necessary to use a dehumidifier.
It is also highly recommended that winter growers purchase a device called a hygrometer. This device can test the relative humidity of your soil as well as your grow room. It is essential to regularly measure the relative humidity in order to stay on top of it and avoid huge spikes or drops in the concentration of water in the air.
In many areas, winter is actually the driest time of the year, as well as being the coldest. If you are not facing issues of relative humidity, then cold dry air will present problems of its own in the grow room. If air is taken in from outside at a temperature of 10°C and an RH of 50%, it will contain water vapour at 4.7g/m³. If this air is heated to 25°C without the addition of extra moisture, its RH will drop to around 20%, which is far too low for healthy cannabis plants to grow.
In the growroom, a moist growing medium along with transpiration will generally raise levels of water vapour in the air. However, relative humidity should remain consistently between 40% and 60%.
Other things to consider when growing in winter
Temperature and humidity are the main issues that winter-time growers will have to deal with. Lighting is usually not an issue as plants are typically grown under HID lights.
Having said that, some hobby growers might still be eager to utilise as much natural sunlight as possible, such as growing on a windowsill. The problem with this is that light intensity or simply the amount of sunlight hours may be insufficient for growth. Each area will vary in its wintertime habits, and each grower should make choices accordingly.
Some clever growers will use extra lighting during winter only, to ensure that their plants have enough light to grow. While plants will usually not achieve the yields and qualities achieved in more favourable times of the year, there are plenty of smart hobby gardeners out there that will ensure their supply remains steady even in the harshest times of the year by following this principle.
Greenhouse growers are similarly affected by the reduction in daylight hours during winter, and unlike those growing on their windowsill at home, additional lighting may attract unwanted attention.
However, some adventurous greenhouse growers will add the supplementary lighting and then make sure that the greenhouse is covered so that light does not escape when it is dark outside. Thick, heavy blackout curtains or Mylar sheeting can do an excellent job here. Then, all that remains is to heat the greenhouse sufficiently and provide adequate airflow, and growing throughout the winter should become possible.
Top 10 Craziest Hidden Cannabis Grow Rooms
Consider growing winter-appropriate strains
Every grower understands the temptation of growing their favourite strains throughout the winter, even if those strains aren’t really appropriate for winter growing. If you can let go of that temptation and choose winter-appropriate strains, you might be able to avoid some of the difficulties in growing over a snowy winter.
Let’s look at autoflowering strains as an example. In as little as 8 weeks from germination of the seed, you can have a ready-to-harvest cannabis plant. This means that a grower can avoid growing throughout the harshest part of the winter and maximize their growing opportunity.
Any strain that contains ruderalis genes is also more likely to make it through a winter. Ruderalis is tougher and hardier than more common strains. It also isn’t photoperiod dependent, meaning it will flower when it’s ready rather than as a response to a change in light hours. It can bloom within 30 days of planting.
Growing in winter might mean doing some additional planning in advance to prevent the demise of your plants. But that doesn’t make it impossible. After a couple of seasons growing weed in a snowy winter, it should start to feel like second nature.
Laws and regulations regarding cannabis cultivation differ from country to country. Sensi Seeds therefore strongly advises you to check your local laws and regulations. Do not act in conflict with the law.