From Seed to Bud: The Cannabis Life Cycle
For those wondering about the stages a marijuana plant undergoes as it grows from seed to potent bud, Chris Bond breaks it down by detailing what to expect from each phase of cannabis plant growth.
Ah, the miracle of life. If you attended a public school health class, you likely had to sit through one or more screenings of some version of a video depicting the formation of a zygote, the gestation period, and ultimately the birth of a human being. The life cycle of a cannabis plant, while not required viewing for class credit or fodder for snickering teenage boys, is no less dynamic, going through several stages itself between seed and harvestable product. It follows a similar trajectory of development as other plants and shares commonality with other developing life forms as well. It begins, as a small seed.
Cannabis Seed Stage
Where it all begins—the seed stage. Not all cannabis seeds are identical in appearance, but there is great similarity among them. A healthy cannabis seed should be firm and light to dark brown. Seeds that are soft or light in color are likely underdeveloped, diseased, or will not germinate. These should be culled as they probably won’t produce a healthy, productive plant. A cannabis seed can remain viable for many years and will remain dormant so long as it is kept in a dry, dark environment. When a grower is ready to start germinating his or her plants, soaking the seeds in water prior to planting, or wrapping them in a moist, absorbent material such as paper towels, will kick-start the seed’s journey into planthood.
Cannabis Germination Stage
Once the seed coat membrane has allowed moisture inside, and so long as the temperature is above 70˚F, germination will commence. The first part to emerge from the seed is a small white taproot, known as the radicle. If the seed is not already in soil, this is the time to get it there. The taproot will be looking for a structure to grab hold of. Once it has attached itself to soil or other appropriate media, it will then send the first shoot up above the soil line. This first above-ground growth will have two pre-leaves, known as cotyledon leaves. These leaves were already formed within the seed and have the job of performing the first bout of photosynthesis, as any of the stored energy within the seed has been expelled during the formation and development of the taproot and cotyledon leaves. It needs to send energy back to the roots and get on with the business of making its first set of true leaves so it can become a bona fide seedling.
Cannabis Seedling Stage
As soon as the cannabis plant has formed its first leaves with its tell-tale “fingers,” the plant has graduated into full-fledged seedling stage. At this point it will get even busier both above and below the soil line. So long as it has adequate water, nutrients, soil or media structure for healthy root development and good air flow, it can then produce a more robust root system and keep pushing out more leaves and branches. Where the line between seedling stage and vegetative stage lies is up for debate, but once the stem starts to thicken and the plant has produced several pairs of new leaves, it is considered to have evolved into the vegetative phase. This phase of development is relatively short, lasting from a couple of weeks to about one month, depending on variety and conditions.
Cannabis Vegetative Stage
During the vegetative phase of cannabis growth, a healthy plant will be creating and storing enough energy to continue pushing out new leaves. Then it can photosynthesize and create more energy to feed the roots and create more leaves, so that it can be as strong a plant as possible in preparation for the formation of flowers. To maximize its potential, a cannabis plant will need up to 18 hours of daylight in this phase. It will keep up this pace until it matures into an adult plant capable of producing flowers. Before it begins its pre-flowering phase, however, the plant will experience its highest levels of growth and will grow six to 10 times its seedling stage size—or more—depending on variety, type, and amount of available light, water, nutrients, temperature, and air flow.
The type of cannabis predetermines its growth pattern. Indica strains tend to develop shorter but denser stems filled with leaves, whiles sativa dominant strains will grow taller but tend to be sparser. With so many different strains and crosses your actual results will vary, but a quick online search will reveal what average heights, widths, and growth rates of healthy strains should be. There is much variability in time spent in this stage. It can last from several weeks to several months before entering the pre-flowering stage.
Cannabis Pre-flowering Stage
Once your plant has reached maturity, but before it’s in full flower, it will begin to develop its sex organs. Cannabis plants are typically male or female, though there are hermaphrodite plants. It is at this critical phase that male plants and hermaphrodites need to be culled, unless your goal is to raise cannabis plants for seed development. You do not want your male plants bursting forth with their pollen and fertilizing your female plants if you intend on harvesting buds with as much tetrahydrocannabinol (THC) as possible.
Fortunately, it is possible to determine rather easily whether your plant is male or female. The males will produce pollen sacs where the leaves meet the stems in the nodes. These are often described as banana, as their shape is oblong, and their color is often light green to almost yellow. If left to their own devices, these will spring forth with their payload of pollen which can travel far and wide. One male can pollinate numerous females.
Assuming you have only female plants or have culled your males, it is time for your cannabis plant to move on into the flowering stage. This is often induced by reducing the amount of available light. In wild-grown cannabis, this happens naturally as daylight length is reduced in late summer and early fall. For indoor cultivation, light should be reduced to about 12 hours per day to trigger flowering. It should be noted this relates to non-autoflowering strains, which are the vast majority of cultivated plants. Autoflowering strains will enter their flowering stage based on age and not light levels. These are typically cultivated strains that have been crossed with the genetics of wild-grown strains.
Cannabis Flowering Stage
Once the cannabis plant has entered the flowering phase, it should no longer be producing leaves or branches. Depending on the strain, cannabis plants will be in this stage for the next several weeks to a couple of months. As time goes on and the buds continue to develop, they may begin to get a distinctive smell. Female flowers will begin to produce long, thin, milky white hairs called pistils. This is what you are looking for up until it is time to harvest. Once the plant leaves begin to yellow or show signs of senescence or stress, it is time to clip off those buds. In most cases it is better to do so too early than too late so as not to compromise the quality of the harvest. Expect to be at this point about two months or so after your plants have entered this stage.
The harvesting stage is when it is time to cut off all those well-formed, THC- and trichome-rich buds for curing, drying, or processing.
All cannabis strains will go through these stages of development, but each specific strain, hybrid, or sub-species has a unique set of developing characteristics and timetables pre-programmed into their respective DNA coding. This entire process can occur in as short a time span as two months, or as long as nine months. Autoflowering strains are ready to harvest on the low end of that range, but yields are typically much lower than with non-autoflowering strains. But, so long as the grower provides a comfortable environment for his or her cannabis babies, they already know what to do and will perform their miraculous journey before your very eyes.
Written by Chris Bond | Certified Permaculture Designer, Nursery Technician, Nursery Professional
Chris Bond’s research interests are with sustainable agriculture, biological pest control, and alternative growing methods. He is a certified permaculture designer and certified nursery technician in Ohio and a certified nursery professional in New York, where he got his start in growing.