Flipping Your Marijuana: When To Go From Veg To Flowering Stages

There are few things in the world more fulfilling than raising a cannabis plant from seedling all the way to harvest, taking advantage of those sticky buds and dense colas right before the curing phase. Unless you are working exclusively with auto-flowering seeds, growers have to know when to flip their growing operation from the veg state to the flowering phase. Within the horticultural world of cannabis, this transition is known as flipping your plants.

Learning when and how to flip your cannabis plants can make all the difference in the world, particularly when looking at your final results. As you will soon find out, flipping your plants at the right time and with the right techniques can take an average harvest before supersizing it into something special.

If you’ve never cultivated your own cannabis before, you should pay close attention. The flowering phase is when harvests are made or broken. Get comfortable, put on your gardening gloves, and let’s get ready to work.

Understanding the Four Growth Stages

Cannabis doesn’t transition from a seedling to a fully grown plant without any work or effort. Cannabis plants have a wildly diverse growth routine that spans four stages, with slight alterations depending on the strain.

The primary growth stages of the cannabis plant include:

• Germination: 3 to 10 Days
• Seedling: 2–3 Weeks
• Vegetative: 3–6 Weeks
• Flowering: 7–11 Weeks

Plants in nature will transition from one stage to the next based upon sexual maturity. Sexual maturity in a plant is based upon the readiness of plants to produce buds and pollen sacs. Plants will naturally make transitions in nature toward flowering when the sun guides them. Plants will notice that the days are shortening and the sunlight is fading, thus triggering their desire to reproduce.

Indoor growers can replicate the flowering-flip part of the process by mimicking the light schedule of nature itself. Shifting from 16 hours on / 8 hours off light schedule to a balance of 12 / 12 can be enough to trigger plants to flower. While this all sounds relatively simple, the process is far more difficult to enact in person.

Let’s explore the flowering phase better now that we understand the four core growth stages of cannabis.

Make Your Measurements

First and foremost, flipping from veg to flower can lead to a need for serious vertical space. Cannabis can double or even triple in height following the flipping stage, and that means indoor growers can quickly run out of space for their treasured plants. Indoor tents need to have enough height clearance to allow for the further growth of your cannabis plants. Limiting the space of your plants can lead to a reduction in yields as well as a waste of space and potential damage.

To know when to begin flipping your plants, measure from the base of the cannabis plant to roughly 12 inches below your lights. When your plants get a third of the way between these two points, you are ready to flip into the flowering phase.

Step One: Light Transition

As you transition from vegetative growth into the flowering stage, the first change that must be made is concerning your lights. When you first begin flowering, your lights need to be changed from a 16- to 20-hour vegging cycle to a 12/12-hour cycle to induce flowering. To make this process a simple one, connect your lights to a timer that turns off for 12 hours per day. 

Note: During this stage, it is integral to seal away any light pollution from the outside world. Plants will rely on lighting to tell them when to begin flowering, and light leaks can cause havoc during this transitional phase.

Step Two: Prepare Your Climate

As your plant transitions into the flowering stage, it is important to reduce the overall humidity levels of the room. Reduce your humidity levels from 70% during vegetative growth to something closer to 50% during the flowering phase. By adjusting the overall relative humidity levels of your garden, you can offset potential mildew and mold issues. 

During this stage, you also want to keep your grow room at a temperature between 68 degrees and 82 degrees Fahrenheit. Again, different strains will tolerate different temperature settings, so be aware of what you are working with. Some plants can withstand tropical climates and high heat better than others.

Step Three: Final Pest Check

If you think an infestation is tough during the veg stage of plant growth, try to handle one during the flowering phase. Pests and diseases are a fact of life in the cultivation world, so take this moment as an opportunity to perform a sweep of your plants. Assess the leaves while examining your growing substrate for signs of mold, mildew, pest, or disease.

Step Four: Fuel Your Plants Correctly

As the flowering stage of your cannabis rises fully into view, your plants will begin to require more and more from their feeding schedule. At this point, you want to incorporate higher levels of magnesium and phosphorous while intentionally reducing overall levels of nitrogen to induce better flowering. 

Switching your feeding program around can be particularly problematic for fickle plants. Make sure to adjust your feeding schedule slowly to avoid stressing out or otherwise damaging your crop.

Flowering: Indica, Sativas, and Hybrids

Does every strain of cannabis go through the same growing and flowering stages? The answer is “eh, kinda.” Strains will vary from one to the next in height, bud structure, and feeding requirements. Indicas tend to double in height following transition into the flowering stage, while sativas can stretch up to three times their overall length. Most cultivators are working with modern strains, which fall into the hybrid paradigm.

To ensure that your harvest is plentiful, make sure to follow the tips outlined above. Taking good care of your crop is an essential part of ensuring an even and good harvest.