What Is A Vegetative Room?
The vegetative stage of plant growth is when your plants will begin to grow rapidly. When this stage starts depends on the source of your plants. If you are growing with clones, you will need to give them time to establish a solid root system prior to moving them into a vegetative room. Plants grown from seeds can be moved over 2-3 weeks after they begin growing leaves and establish their root systems. The lighting in vegetative rooms can vary, but most cultivators aim for a PPFD of 300-600 µmol/m2/s. It is possible to give plants to much light during the vegetative stage which can lead to a condition known as nutrient burn. The excess light causes the plants to absorb more nutrients than they normally would. When this happens the points and edges of the plant’s leaves will begin to turn brown. Some cultivators prefer using grow lights with more blue light in their spectrum during the vegetative stage, as this has been shown to make plants shorter and stockier with larger leaves. Often growers will have rooms dedicated to the vegetative stage of growth. That way by the time the crop currently in their flower room is harvested, their next crop is ready to move in to take its place. The layout and configuration of these rooms can vary greatly depending on the needs and preferences of the grower.
Single-level Vegetative Grows
Single-level vegetative grows are configured so all the plants are placed at an equal height with lights suspended above the plants. One advantage of this growing style is that it allows cultivators to easily see all of their plants at once. This makes it easier to evaluate the health and track the development of their plants. Additionally, this grow style reduces the amount of light spillage. Light spillage is when photons produced by your grow lights miss the plant canopy and do not contribute to photosynthesis. This issue is most pronounced for grow lights placed near the edge of a canopy, where there are no additional plants to absorb light emitted at angle. With a single-level “sea of green” plant arrangement more of your fixtures are positioned away from the edge of the canopy, meaning less wasted light.
For larger vegetative rooms, our FL-1 LED Grow Light might be a better fit. This fixture’s high light output is designed for the flower stage, but can be used for vegetative stages as well. By mounting these fixtures higher above the canopy than they are during the flowering stage, the light it produces is dispersed over a larger area. When you spread the same amount of light over a larger area, the intensity of the light hitting the canopy decreases to level suitable for a vegetating plant. If the light hitting your canopy is still more intense then the plants need, these fixtures can be dimmed until they reach an ideal level. Dimming reduces both the light output and energy consumption of the grow light.
Multi-level Vegetative Grows
For growers with limited space available, multi-level grows can be an ideal set up to maximize the amount of growing space at your facility. This style of grow stacks plant canopies vertically using racks. Each layer of plants on the rack has low-profile LED grow lights placed directly above them. This style of growing can only be achieved using LED grow lights, as traditional HID fixtures using HPS or CMH lamps will burn plants if placed that close to the canopy. This is a common configuration for vegetative rooms, as many facilities want to dedicate their larger rooms to plants in the flowering stage. The best fixture for this application would be the VL-1 LED Grow Light. This fixture has an extremely low-profile design making it ideal for vertical grows where there is limited room between each layer of the grow rack. The lower profile allows for more layers per rack, while maintaining a proper distance between your grow lights and each canopy. It was designed with adjustable light bars allowing cultivators to either spread or concentrate the light coming from this fixture depending on their needs.
How Long Should Grow Lights Be On?
During the vegetative stage, it is recommended to have your light turned ON for 18 hours and OFF for 6 hours in complete darkness each day. We suggest using a timer to automatically set your daily light cycles. Since you want a PPFD of 300-600 µmol/m2/s, we recommend using our VL-1 light on the highest dim setting for a 5’x5’ or 6’x6’ area while hanging it 12 inches above the top of the canopy. If you have a smaller area, you can dim the light output down by an increment or two, or just raise the light. You could also use our FL-1 light on the lowest dim setting for the vegetative stage.