Step three: Marijuana Vegetative Stage - For Indoor Growing

December 09, 2018

By Ayad Maher and Andrew Gordon


After the seedling stage, when your plant is around 4 inches high and/or has developed at least 3-4 sets of “true” leaves, it's time to transport it to a bigger pot, such as a 5 gallon container.

Three simple steps to do this:

  1. Prepare your large container first: add soil, then dig a hole in the center, big enough for your seedlings plant roots and the soil surrounding them to fit comfortably in the hole. If you started in a solo cup or other stiff material, you can use the first pot as a mold to dig the hole in the new pot to the appropriate size.

  2. Carefully take the plant out of the small container. Dig around the edge of the planter with a butter knife to separate the root ball from the edge of the pot if necessary.

  3. Put the main stem of the plant between your middle and ring or index fingers and invert the pot. The soil should come out in a big clump with the roots, roughly the size of the hole prepared in the first step, and should rest easily in your upright palm. Gently place the plant in the hole you constructed in the large container.

It is easiest to transplant about halfway between waterings, in my experience. If the soil is too moist, it is more difficult to separate from the first container and easier to damage the roots since the entire root ball is heavier. If it is too dry, it is also easy to damage the roots since more soil will fall away and expose them. Thus, I try to transplant when the soil is dry at the top but still moist below the first inch or two from the surface.

Related article: Top 7 Online Stores for Marijuana Growing Supplies and Equipments

No matter how careful you are, the process may still cause some minor damage to the root system and it will take some time to recover. It is natural for the plant to be stressed following a transplant; I also recommend cutting back on nutrient concentrations or cutting them out entirely until the plant shows signs of growth again (which may be immediate, meaning you don’t even need to cut nutes). It is best for the process to take place at night, where it will have some time to settle down before it starts the photosynthesizing process in the morning.



After moving the seedlings to larger pots, it's time to get the climate ready for the plants to grow.

Lights: Your lights should be ON 16 to 20 hours a day. Some growers will even run lights 24/7 for their vegetative plants. There is no conclusive data to suggest that anywhere from 16 to 24 is better or worse. They will need at least 16 hours on in order to remain in vegetative- any less, and you risk them beginning to flower, as shorter light duration imitates the coming of winter, i.e. the natural signal to develop flower.

You can control them manually, but it’s a lot easier to use a light timer controller. Even if you are on a budget, I highly recommend a timer-  they are inexpensive, and not having to worry about turning your lights on/off twice a day is a huge relief. This will also help avoid unnecessary stress in case you forget to turn the lights off or on at any point. If you’ve been reading the previous entries in our Indoor Growing series, you’ll recall the emphasis placed on avoid light leaks. The same principle applies to the light schedule: minor fluctuations can lead to undue stress.

Related article: 5 Reasons Why You Should Grow Your Own Weed

Keep in mind, weed plants require around 15% of blue color of the light spectrum to avoid stretching. Insufficient blue will cause thinner stems and eventually a weak plant with longer internodes (part of the plant stem between two of the nodes from which leaves emerge).

As we suggested in our previous post; for small scale growing (up to 6 marijuana plants), T5 fluorescent (or compact spiral fluorescent, CFLs) will do the job just fine.



Temperature: During "day time," when the lights are ON, the ideal cannabis grow room temperature should be 78 degrees Fahrenheit. If you were neurotic person in a way, as I am, maintaining the exact same temperature may drive you crazy, so don't beat yourself up, a range between 73 - 83 would do too.

It's OK for the temperature to go down to 60-65 degrees Fahrenheit when the lights out, no problem, but not lower than that. You also want to avoid temperatures exceeding 85 F if possible. Above 85 F, plant growth begins to stunt, and stunting becomes more severe as temperature continues to rise.

Humidity: As for the humidity, 45% - 65% should be maintained in your marijuana grow room at all time. Clones and seedlings prefer to have higher humidity, as this promotes moisture collection via leaf surface as opposed to collection through the roots. Clones/seedlings do not have fully developed root systems, and I believe they are more efficient at collecting moisture through their leaves while they develop the root system necessary to sustain themselves.

Watering: Water your marijuana plants only when the soil is completely dry, not even damp. Wait until the top of the soil is about an inch deep dry - just poke a hole in the soil using your finger, if it was dry all the way to your first knuckle, it means the plant needs watering. You can also look for visual cues which imply that the plant needs water, the most obvious of which is drooping. Overwatering is much more detrimental and slower to correct than underwatering; always play it safe and don’t water until you are confident that the plant is ready. They will let you know when they need it!

Related article: Top 7 Online Stores for Marijuana Growing Supplies and Equipment

As for watering the plant, you want to soak the pot. Add water until you see extra water starts running off and draining out the pot's bottom. The rule of thumb is runoff volume should equal 10-20% of the watering volume.

Keep an eye on the watering process, take notes and create a schedule. Familiarize yourself with the watering/dry cycle. Again, the plants can really help you learn the schedule they prefer- look for those visual cues if you are not certain of how frequently they need to be watered.

Air circulation and ventilation: we talked about this on our Step One: How to Build the Perfect Indoor Grow Room (For up to 6 Plants). Sufficient circulation and exchange is crucial to keeping your plants prosperous and healthy. The process will also help to stabilize your temperature and relative humidity level.

  • Make sure to have a fan (or multiple fans, depending on the size of your grow room, and the size of the fans) to circulate the air.

  • Avoid having fans blowing directly on the plant. Blowing underneath the canopy is fine, and even recommended if you are having pest issues, or if you have high humidity, or humidity “pockets” or “zones” beneath the canopy.

  • Leave an opening in the grow room at all times to let the old air out and draw fresh air in. These should be two separate openings; be aware of potential light leaks from these areas.

Ideally, you will evacuate the room/tent volume two to three times per minute. The best way to do this is to set up an exhaust fan with ducting, which most grow tents are prepared to support. Exhaust fans are rated by how much air they can move in a given amount of time, in units such as cubic feet per minute (CFM, or ft3/min)

In order to determine how much ventilation is necessary for your space, you will have to take some quick measurements and run a few quick calculations- fourth grade level stuff. Here’s a quick rundown and example:

  1. Measure the dimensions of your grow space- length, width, and height. If you are using a grow tent or built a custom grow space, you should already know these! My grow tent is 4 ft x 4 ft x 7 ft.

  2. Calculate the volume of your grow space. The formula is L x W x H. Thus, 4 x 4 x 7 = 112 ft3 (cubic feet).

  3. We want to evacuate two to three tent volumes per minute. Our tent volume is 112 ft3. Let’s see what two to three tent volumes looks like: 112 x 2 = 224. 112 x 3 = 336. Thus, we want to look for an exhaust fan that can move at least 224 CFM, and anything higher than 336 will be overkill. There’s nothing wrong with overdoing it by a little, and most fans are built with speed controllers which allow you to fine tune the amount of ventilation. You can also purchase the speed controllers separately if your fan doesn’t have one.


Nutrients: During the vegetative stage, you want to make sure you have enough Nitrogen (N) in your soil. This will be provided by your potting soil and fertilizer solution. If you were using the potting soil we suggested in our previous post (Step One: How to Build the Perfect Indoor Grow Room), FoxFarm Ocean Forest, then you should start your fertilizer solution at no more than half the manufacturer’s recommended strength.

Only increase the fertilizer solution potency if you have identified nutrient deficiencies. As with watering, it is easier to overdo it on nutrients and cause toxicity and burning than it is to develop severe deficiencies from underfeeding. Toxicities tend to be more common in indoor grows than deficiencies.

To learn more about the best type of soil for your marijuana garden, here is The Definitive Guide To The Best Soils For Cannabis.


A "just right" vegetative stage length is very important to guarantee good quality crops, it also determine the strength of your plants, however, time is different from a strain to another.

In general, the recommended minimum vegetative stage length for cannabis is around 4 weeks. However, you still want to keep an eye on your plants before proceeding to the next stage; The Flowering Stage. You want to make sure that your plants are 18 inches high and have developed at least 5-7 branches.

Some stains may reach the 18 inches before developing the 5-8 branches, since you have a limited space in your grow room, I suggest to trim or prune your marijuana plants till both conditions apply (18 inches and 5-7 branches).

One of the best parts of growing indoors is the ability to control the vegetative duration for your plants. Four weeks in vegetative is usually enough to get a decently sized plant with minimal training ready to flower. However, you can extend the vegetative length indefinitely to allow your plants to grow larger and to facilitate training, which can result in substantially larger yields and more consistent buds. 


The best way to improve your yield from each harvest is to train your plants. Training involves manipulating the growth pattern of the plant by bending, tieing, and even cutting sections of the plant off. Training techniques are broken down into two broad categories, but are often used in tandem to achieve great results. Both sets of techniques introduce stress, as the names imply; this means that, although the final outcome is a larger and healthier plant, growth may be temporarily stunted or set back. In almost all cases, these delays are made up for with increased yields. Proper training is far and away the single most effective factor for increasing yields in otherwise healthy and successful grow environments.

Low-stress Training: Low-stress training (LST) is the process of bending the limbs and new growths of the plant in order to force them to grow in particular directions or orientations. The goal of low stress training is to develop a flat, even and consistent canopy with multiple tops, whether from multiple plants, or a single plant that has been topped. We’ll cover topping in the high-stress training section below.

There are a number of ways to conduct your low-stress training. The best tool for the process, for a beginner, is the twisty-tie. If you eat bread, you probably know exactly what these are, even if you know them by a different name. Using twisty-ties is simple, cheap, and effective for most any LST goals. They can be purchased in rolls of various length that can be cut to size for your needs. You will need more as your plants get larger, but a single roll can easily last multiple grows, especially if you re-use the sections and use consistent training methods (using the same size pot and tieing the same limbs during each grow cycle). Twisty-ties are also available in a variety of thicknesses, with thicker types generally having a rubber coating which will not cut into the plant.


Another common tool for low-stress training is a trellis or net through which the limbs of the plant are woven in order to restrict their grow space. This tool is often referred to as a “scrog,” or “screen of green.” The scrog is ultimately more effective, even if somewhat less versatile, than the twisty-tie. I don’t recommend scrogging for beginners as it can be difficult to water your plants and drain their trays due to the presence of the screen. Scrogging restricts your ability to move your plants, and is best suited for hydroponic, aeroponic, or drip-fed media.

High-stress Training: High-stress training (HST) is an umbrella term for a number of processes that introduce significant stress to the plant. We will cover a few of these techniques: topping, fimming, and supercropping.

  • Topping is the process of cutting off a growth tip just above a node. As a result of topping a single limb, that limb will (usually) grow two new growth tips. These new tips will eventually grow to the size of the original tip, and eventually they will even surpass the original in size. Thus, topping a limb results in twice as many tops of similar size; it is easy to see how this can improve yield!

  • Fimming (FIM stands for “fuck, I missed”) is a similar process to topping. Instead of snipping the tip right above a node, instead you snip the new growth tip at the very top, stressing the young fan leaves. I do not personally use this method, but it is supposed to work very similarly to topping, while introducing less stress and having a faster recovery time. The result of the process should be multiple new growth tips from what was previously a single tip.

  • Supercopping is the process of tenderizing a small section of the limb. This is usually done on smaller sections of stem on younger plants by pinching a rolling the stem between your fingers. As a result of the tenderization, growth will be temporarily stunted. As the plant recovers, it will develop a large knot at the stressed area which is believed to improve nutrient flow, and thus growth beyond that part of the limb. The goal of the process is to make the firm stem softer and fleshier- it should hang limp, but not be torn, and not have insides exposed to the air at all. This technique, admittedly, is difficult to perform correctly because it is easy to overdo it, or underdo it.

LST and HST may seem complex for a first-time grower, but I recommend trying at least one or two of these techniques on your first grow. The only way to learn how to master these techniques is to practice them! With each grow cycle lasting 12 weeks or more, it is crucial to learn as much as you can from every cycle. Don’t be afraid of stunting a seedling or clone, or pushing your harvest a week or two back in order to allow for more vegetative growth and training time. It is almost always worth spending more time training instead of flowering as soon as possible- the extra time is made up for by larger harvests. 


Andrew Gordon is from the northeast USA, currently resides in Vermont with his wife, and has over 5 years of experience with cannabis cultivation. General interests include cultivation, extractions, skiing, reading books and playing video games. Professional experience includes mostly laboratory work in biotech. For any questions, you can reach to Andrew through his email: 

Ayad Maher is a Cannabis Industry Entrepreneur, Blogger & Activist. eCommerce Specialist and Owner of a 420 Life Style Company; Monroe Blvd, 421Store and GoodyCBD.


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