Cannabis is grown from one of two sources: a seed or a clone. Seeds carry genetic information from two parent plants and can express many different combinations of traits: some from the mother, some from the father, and some traits from both.
In commercial cannabis production, generally, growers will plant many seeds of one strain and choose the best plant. They will then take clones from that individual plant, which allows for consistent genetics for mass production.
If cannabis is legal in your state, you can buy seeds or clones from a local dispensary, or online through various seed banks.
Cannabis seeds vs. clones
For the typical homegrower, it may be easier to obtain cannabis seeds rather than clones. Growing from seed can produce a stronger plant with more solid genetics.
Plants grown from seed can be more hearty as young plants when compared to clones, mainly because seeds have a strong taproot. You can plant seeds directly into an outdoor garden in early spring, even in cool, wet climates.
If growing outside, some growers prefer to germinate seeds inside because they are delicate in the beginning stages of growth. Indoors, you can give weed seedlings supplemental light to help them along, and then transplant them outside when big enough.
Most seeds that you will buy are regular seeds as described above, but here are a couple more types.
How weed seeds work
Cannabis can be either male or female—also called “dioecious”—but only females produce the buds we all know and love. For reproduction, males have pollen sacs and pollinate females, causing female flowers to produce seeds.
Once cannabis seeds are mature, the female plant begins to die, and seeds are either dropped to the ground where they grow into new cannabis plants next spring, or the seeds are harvested for processing into seed oil or food products, or stored so they can be sown in the ground later and become the next generation of plants.
To get the buds found in medical and recreational stores, female cannabis plants are grown in an environment without males—or the males are removed from the area before they release pollen—so the females don’t create seeds. Females can then focus their energies on producing buds and not seeds—this high-potency marijuana is traditionally known as “sinsemilla,” meaning “seedless.”
Some varieties of cannabis can produce male parts alongside female flowers on the same plant, especially if exposed to environmental stressors. These plants are known as hermaphrodites, and sometimes they can self-pollinate to create seeds.
Pros and cons of using cannabis seeds
If buying from a reputable breeder or seed bank, growing from seed is the best way to ensure your plants will have solid genetics and start clean, meaning they won’t come with diseases or pests.
Also, buying from a reputable breeder or seed bank will give you a sense of what a particular strain will look and smell like, how it will grow, and how much it will yield at harvest.
The main drawback to growing from seed is there is no guarantee as to what you’ll end up with—if you buy a regular pack of cannabis seeds, it will be a mix of males and females. You’ll need to sex them out (more below) to identify the males and get rid of them, because you don’t want your females producing seeds.
Sexing marijuana plants can be a time-consuming process, and if you don’t catch males, there is a risk that even one males can pollinate your entire crop, causing all of your female weed plants to produce seeds.
One way to avoid sexing plants is to buy feminized seeds (more below), which ensures every seed you plant will be a bud-producing female.
You can also minimize headaches and avoid the hassle of seed germination and sexing plants by starting with clones.
Genetics is just a fancy word for your seeds, and that’s what you need if you want to grow cannabis from seeds! The term can also refer to cannabis clones, but for the beginning grower, seeds are much easier to source. If you are interested in starting from clone stock, you can generally purchase them from a qualified local grower, assuming there are no laws against clone sales in your jurisdiction.
But which Cannabis seeds to buy? That depends on your grow style and personal preference. You’re going to choose an Indica, Sativa, or hybrid or course, but do you want regular seeds, feminized seeds, autoflowering seeds, or some combination? With regular seeds you’ll have to remove any males before they mature and pollinate your females or you’ll end up with seedy, low-quality buds. Additionally, cannabis grown from regular seeds will only flower in response to a change in the photoperiod (how many hours of light they are exposed to) so farming these types of seeds requires a bit more care and attention than autoflowering strains (which produce buds when they are old enough, not in response to the light) or feminized seeds which eliminate the need to monitor for males. If you’re looking for the simplest type of seed, you can go with autoflowering, feminized seeds.
Cannabis grow lights and the vegetative phase
The vegetative stage is where your plants bulk up and develop the frame necessary to support the eventual flowers. As mentioned in the genetics portion of this guide, your seed choice will influence the amount of care and attention you’ll need to provide. If you choose regular seeds, the vegetative stage of cannabis growth will require an 18-6 light cycle (18 hours on and 6 hours off). The size of your grow will determine your light requirements and there are many choices. I tend to recommend LED lighting because they’re energy efficient and produce less heat than other types of grow lights, which will help keep overall temperatures down in your grow. Check out a few LED recommendations for your cannabis grow here. Keep in mind the size of the light if you’re using a grow tent to assure it will fit.
The vegetative phase is also where you begin monitoring the sex of your plants and then remove and destroy the males as soon as you identify them. If you have access to female clones, this step isn’t necessary, but it will be if you grow cannabis from seeds. You can check out our guide to sexing your plants here. Again, this is a step you need to take when growing from regular seeds. If you use feminized seeds you can be nearly 100% certain that all of your plants are female (1 in 1000 feminized seeds may turn out male).
Since the vegetative stage of growth is where your plant will bulk up and develop its framework, you’ll want to make sure you use some quality nutrients to ensure your cannabis grows strong and healthy.
A nutrient bundle is a great way to save money.
Last but not least, an important consideration during the vegetative stage is pest control. It’s important that you monitor for pests and diseases during the duration of your grow to deal with any problems before they reach crisis level and threaten your crop. Fortunately, close monitoring and cleanliness will help you avoid most of these problems, but should you encounter pests or disease, there are a number of great, organic products that can take care of nearly any problem. And don’t worry, we recommend only products suitable for treating consumable plants.