It is miraculous to watch a seed sprout, slowly open up and develop its first set of true leaves. In this instant the next stage of their life begins, the vegetative phase of growth taking over when a seedling graduates.The nutrients and DNA stored within the seed will nourish and guide it for a short time, preparing for the shift to the critical vegetative phase.
Processes Driving the Vegetative Phase
Vegetative growth is the portion of a plant’s life following germination and preceding flowering/reproduction. This stage is most characterized by how swiftly and noticeably plants are able to grow. Stalks get taller and thicker. Every day more leaves emerge. Branches protrude from new nodes appearing on the stretching stalk, all while roots are expanding below the ground, anchoring the plant in place, seeking water and nutrients. The incredible amount of green growth during this stage is due to significant processes occurring within the plant.
Vegetative growth takes place during the spring and summer as the days are getting longer and available sunlight is at its peak. Cell development kicks into high gear when exposed to the waves of the summer sun. New cells are rapidly produced, adding to the mass of the plant. Existing cells begin to stretch and the absorption of water and nutrients leads to cell elongation, allowing the plant to grow taller and wider.
All of these new cells are synthesized through photosynthesis. Photosynthesis is the process by which a plant is able to convert light energy into chemical energy, fueling its continual growth. Light is captured by the green leaf pigment chlorophyll, then combined with water and carbon dioxide to fuel photosynthesis.
Lucky for us humans, plants can perform this miraculous process, as oxygen is one of the byproducts of photosynthesis. The other products, more important to the plant, are carbohydrates like glucose and fructose. These sugars are sent to the roots, stems and leaves as a source of energy. The sugar molecules working and combining together, form complex carbohydrates like cellulose and starch. Cellulose directly builds the plant by constructing cell walls and tissues.
Requirements for Maximum Vegetative Growth
First and foremost, cannabis plants need access to direct sunlight all day long. Light exposure maximizes the energy absorbed by the foliage through the chloroplasts and promotes photosynthesis. The higher the energy input, the more plant material can be generated, which leads to bigger, stronger and healthier plants.
Water is another integral ingredient of the vegetative phase. Water allows the cells to expand and stretch leading to growth of the stalk, stems, leaves and nodes. It is also the main mode of delivering critical nutrients throughout the plant. Absorbed through the roots and distributed up the stalk to all the extremities, the transport of water and minerals supports continued apical growth. It’s almost impossible to overwater when there is ample sunshine, heat and nutrients.
The most well known driver of vegetative growth is the macronutrient nitrogen. It is a primary element that makes up chlorophyll. Without an abundance of that green pigment, leaves yellow out and can’t absorb light energy, leading to stunted plants and death. Nitrogen plays an important role in the formation of proteins, enzymes, hormones and vitamins as well as regulating phosphorus, potassium and multiple micronutrients. It stimulates the formation of buds and increases the amount and quality of flowers set, positioning the plant for success as it converts from the vegetative to flowering phase. Some typical fertilizers used to ensure sufficient nitrogen uptake are guano, fish emulsion and blood meal.
Potassium ranks second behind nitrogen as far as importance to overall plant growth. The presence of potassium is necessary for numerous critical functions of the plant. It activates the majority of enzymes within the plant, helps deal with stress brought on by exterior conditions, regulates stomata and is pivotal during photosynthesis and the absorption of water and nutrients. Good sources of natural potassium include alfalfa meal, kelp meal, wood ash and compost.
The presence of available phosphorus is imperative for all plants, especially flowering plants like cannabis. The element is responsible for energy transfer throughout the plant. With deficient phosphorus roots can’t develop properly and the number of set flowers is diminished. Phosphorus is needed for all phases of plant life, but is especially vital for forming strong roots during the vegetative stage of a young plant. Bone meal, guano and rock phosphate all contain dense concentrations of phosphorus.
As foliage grows, so do the roots. The quantity of water and nutrients must increase as plants flourish, encouraging the roots to stretch in search of hydration and nourishment.
Space for Roots
During the vegetative stage, plants are very receptive to transplanting. Especially when it affords their roots more space to grow. Rootbound plants are relieved and more than ready to spread their roots and grow to new heights after being transplanted into a larger space.
When it comes time to transplant into the final pot or bed, bigger is better. Roots will take as much space as they’re given, provided they have adequate moist, nutrient dense, loose soil. A robust root network can support large amounts of vegetation and flowers, ensuring higher yields at the end of the season.
Vegetative Growth is Crucial for Development
Stout, woody stalks and colas are the perfect support system for lush, dense flowers. A healthy, prosperous vegetative phase constructs the scaffolding that will support the cherished harvest. During the vegetative stage plants have almost unlimited potential. When all of its needs are met, cannabis grows at an incredible rate and produces unbelievable amounts of biomass in fiber, foliage and flower.
The importance of the vegetative phase to a plant’s overall health and ultimate yield can’t be understated. No living thing can grow successfully without first establishing a sturdy foundation and form. Cannabis plants should start the flowering season with a strong, solid structure. When the processes vital to vegetative growth are observed, necessary elements are supplied and ideal conditions provided, the framework for a heavy harvest rests reliably on healthy roots, stalks and stems.
Nitrogen Plant Architecture - NIH Study
Potassium in Plants - NIH Study