The Plant Life Cycle
It’s easy to just do what other growers tell you to: do this feeding regimen, do that grow light cycle, keep your grow room at XYZ temperature, etc… And while that may be good knowledge for commercial growers, we think it’s useful to understand exactly what happens at each stage of your plant’s life. The more you understand what’s happening while your plants are growing, the easier it can be to spot weak points in your grow and fix them before it’s too late. In this article, we’ll be going over what happens at the beginning, middle, and end of a plant’s grow cycle step by step, so if you’ve ever wondered what’s going on while your plant’s growing this is what you've been looking for.

Plant Germination: From Seed to Sprout

Plantlife all starts with the germination of the seed. All the plant needs at this point are water, air, and warmth to begin its life. Whether you germinate in soil, water, or in a damp environment, the seed will absorb enough water to activate its digestive enzymes.
Detailed illustration of plant parts
Once it breaks down all of the nutrients the seed has inside, the seed will produce a tap root that shoots out of the shell. This means the plant’s ready to grow, so it will start to push its way upward as the taproot begins to look for and take in nutrients in its medium. It will also sprout its first two leaves (called cotyledons) which will open up the seed more to get sun. Once this happens your plant is ready to start becoming a seedling, as it’s now open and taking in water, nutrients, and sun. After the cotyledons are growing, your plant’s job is now twofold: not only will your plant’s first set of leaves need to be grown, but this is also the stage in which your plant’s root network will begin to blossom from that single taproot. If your plant can grow a good initial network of roots and it has plenty of nutrients available, it’ll start to thicken its stem and grow a few nodes high. Once it’s around 4-5 nodes high and healthy leaves are growing (usually around 3 weeks) your plant’s going to be entering its vegetative stage.

The Vegetative Stage: Growing Branches, Stems, and Foliage

Once a seedling is sprouting lots of leaves after about 3 weeks it’ll be in its vegetative stage. Also known as the “growth” stage, this part of your plant’s life is focused on increasing (in size and quantity) its leaves, stems, and roots to absorb the nutrients it needs to grow.
You’ll find that nutrients in this stage are absorbed pretty frequently. That’s because plants now need more than water and sun to grow. While vegging you’ll see that your plants also need metal and chemical elements in soil (or hydro) to begin growing their sexual organs. Note: some plants have both sexual organs and will pollinate themselves, whereas other plants will have male or female organs that need to interact to pollinate. When a plant is vegging it will grow upward, making more leaves and strengthening stems and branches. This lasts for around 6-8 weeks, and toward the end of the vegging cycle a few things will happen:
  • The sex will start to become apparent (which may or may not be a good thing),
  • Your plants will begin to grow outward instead of upward (readying themselves for possible flowering)
  • A calyx will form around the nodes of your plant’s branches
Some people call this last little bit of vegetative growth the “pre-flowering” stage, but no matter what you call it once your plants start to focus their energy on growing out it’s time to switch its lighting to its flowering light cycle, which reduces light exposure by 4-6 hours or more.

The Flowering Stage: Growing Flowers and Buds

During the flowering stage of a plant’s life cycle, your plant will produce what it needs to reproduce: pollen and flowers. Males will produce pollen to pollinate the female plants’ flowers so they can keep producing more plants. In nature, plants know how long their life expectancy is, and when the sun goes from lighting them 18 hours down to 12 hours or shorter a plant will know that its life cycle is almost complete. When that’s the case plants will stop trying to “grow” leaves and branches, and instead, start to focus its energy on producing the means to bear offspring. To do this, plants are usually taking up more potassium and phosphorus.
Pollination- Now, depending on the plant, the flowering stage can mean lots of things. In tomato plants and some flower varieties, this stage will produce pollen that will be given to itself to produce fruit and flowers that will begin the growth cycle all over again- these are “self-pollinating” plants. Other plants, like  fruit trees, have a male plant that shoots pollen out (or is available to a passer-by) that is taken in by the female flower to make seeds: the beginning of a plant’s life. Fruit and Propagation- The result of the flowering stage is to produce something that will carry seeds so that the species of plant can survive. In pine trees that means making male and female pine cones that will cross-pollinate and make more trees. Others, like fruit trees and flowers, produce fruit and flowers that are naturally eaten by an animal moving along. Once the fruit- containing seeds- is eaten it is then digested by the animal and the “fertilizer” that comes from the animal is left on the ground to be watered and planted all over again. Some growers prefer to keep male and female plants separate to use the plant sex’s properties pure, while others like to crossbreed genetics of one plant into the other to make a new plant or tweak the property of a plant.

Harvest: the Final Stage of Growth

Detailed illustration of a plant life cycle
Although the harvest stage of a plant is more of a farmer-based concept, it’s worth mentioning the afterlife of a plant. “Harvest” means to gather, and it’s something that we normally associate with a plant’s usable material. Whether we harvest fruit and vegetables for eating, leaves and foliage for extraction or the seeds for future planting, the end of a plant’s life to a farmer are when we’re ready to take what we need from it. In a larger sense, the “harvest” stage of a plant’s life can also be seen as the stage in which parts of the plant are consumed by nature. If fruit and vegetables are ripe they will be eaten by an animal, and when they digest it the seeds will be deposited elsewhere. If not, fruit and vegetables over ripen, fall from the plant, and bugs and bacteria will break it down so the seeds can be planted in the ground. When nature “harvests” a plant and that plant dies, the life cycle of the plant is complete. But as all growers know, just because a plant is dead it doesn’t mean its family is not. And like nature, we will get the seeds we need and begin the life cycle of a plant all over again- just like in nature.

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