Chapter 20

VEG Phase Instructions

In VEG phase you simply need to focus on proper watering, temperature and humidity control, pest prevention, and a few plant maintenance tasks like “topping,” “defoliating” and “debranching.” Of course, you’ll ensure that airflow is good and if you’re growing from clone, you’ll do some transplanting. If you’re growing from seed in a plant’s final pot, then you do not have any transplanting to do.

During the VEG (vegetative) phase, cannabis plants grow roots, branches and leaves, but not flowers. In VEG phase, cannabis plants are kept under consistent 18/6 lighting or 24 hours of lighting a day. 18/6 means 18 hours of light and 6 hours of darkness. You should always use a light timer to maintain a consistent 18/6 light cycle.

Analog light timers are simple and easy to use compared to digital ones. Digital light timers are ok, but analog timers are just simpler to use and dare I say foolproof.


The VEG timelines for clones and seeds are slightly different.

It does take a bit longer to grow cannabis from seed than from clone. So if you’re looking for a head start, then grow clones.

With the Green Carpet Growing indoor growing system, keep your plants in VEG for about 30 days, so that’s 25 – 35 days give or take.

However, when you’re growing by seed, keep plants in VEG phase for around 60 – 90 days.

Once you flip to 12/12 you start transitioning to FLOWER phase, but don’t start counting the weeks of FLOWER (Flower week 1, Flower week 2, etc.) until you see flowers clearly developing. It takes a little over a week usually after you flip to 12/12 for flowers to form.


VEG timeline growing from CLONE:

Day 1: Plant cannabis clone into solo-cup (or a 1 gallon pot).

Around Day 10: Transplant clone (if roots are established) into a 2, 3, or 4 gallon pot.

Around Day 15: “Top” your cannabis plant (after it has at least 5 nodes of growth.)

Around Day 30: Transplant into 5, 7 or 10 gallon pot and switch to FLOWER phase light cycle (12 hours on / 12 hours off).


VEG timeline growing from SEED:

Day 1: Plant seed in a 5 gallon pot (or 4, 7, or 10 gallon pot.)

Around Day 30 – 40: “Top” your cannabis plant after it has at least 5 nodes of growth. A node of growth is where new stem emerges from the main stalk.

Day 60 – 90: Switch to FLOWER phase light cycle (12 / 12)


Here’s what to focus on growing cannabis indoors in VEG phase:

1. Water properly. Both underwatering and overwatering should be avoided.

2. Ensure temperature and humidity are in the target ranges. In VEG, 50 – 60% RH is the target humidity and 60 – 80 F is the target temperature. Check your hygrometer often.

3. Ensure good airflow in your grow tent 24/7. As long as you have a fan exhausting air out of the grow tent and an additional fan to gently circulate air inside the grow tent, you’re all set.

4. Apply a pest control spray (like Organocide) 1x a week. Apply more often when you have pests or diseases.

5. “Top” 1x and “defoliate + debranch” for plant maintenance and better yields and bigger harvests. The goal is to shape your plants and fill the “canopy” space.

6. Transplant clones from a solo-cup or 1 gallon pot – to a 2 or 3 gallon pot – and finally to a 5 or 7 gallon pot right before you flip to FLOWER phase.


These are the six things to focus on in VEG phase in your home grow. Plain and simple.


TIP: The larger the pot, the larger the roots, and the bigger the roots, the bigger the fruits! Make no mistake about it, bigger pots produce bigger plants and thus, bigger yields. Compare the stalk and branch thickness of plants grown in 2 gallon pots vs. 5 gallon pots, and you will see a noticeable difference. Thicker, stronger branches are able to produce thicker, stronger flowers.



1. Water properly. Both underwatering and overwatering are tempting to new growers, but both must be avoided.

Overwatering is the #1 cause of problems for new growers. Under watering happens when you forget about your plants or water sparingly, if at all. If you underwater, then the leaves droop / wilt and eventually get dry, then crispy and brown. If you overwater, then the leaves droop / wilt and they curl, and eventually turn yellow. When overwatered, the roots get suffocated and the plant can’t uptake nutrients and nourish itself. As a result, you’ll see deficiencies show up on the leaves.

Water too much, your plant drowns; Water too little, your plant starves. If you water too much, then the roots will get suffocated, fungus gnats will breed in the soil, and the leaves will “claw,” droop, turn yellow, and eventually the plant will stop growing all together. Overwatering causes stunted growth and it can kill your plants. Nursing a stunted plant back to health takes a really long time. In fact, it’s usually faster to start over with a new clone or seedling if your plant is stunted.

Although overwatering is worse than and more common than underwatering, underwatering can also kill your plants if you don’t water them for weeks. Here’s the deal. If the soil is very dry, the pot is light, and the plant is wilting, then the problem is easily diagnoseable. Verdict: underwatered! However, just because you see a severely wilted plant from underwatering, don’t assume it is dead. Not so fast! Water it slowly and it give it a day or two to see if it comes back to life on you. Some will. A few won’t.

By the way, don’t water or spray the cannabis plant’s leaves directly. You simply water the soil, slowly, as needed.

Also, don’t just stick your watering pitcher or watering apparatus into the grow tent and try to water your cannabis plants all willy-nilly like that. Instead pull each individual plant out and bring it somewhere to water like a bath tub, shower, sink, or get a portable bucket or tub that can contain the run-off water. Excess water will seep out the sides and bottom of the pot, so showers, bath tubs, and sinks make excellent watering stations.


Type of water to use: 

Most tap water and bottled water is fine to use. Use water that has a ph of 6 – 6.8 ph ideally. The best way to bring ph down and feed the soil is with plant molasses.

PH your water:

You’ll have to test the water to know what the ph is. To do this, use a ph test solution kit. Just fill the cylinder up halfway with water and then drop 3 drops of ph test solution, place the cover on and shake it. After 2 – 3 seconds of shaking the cylinder, then you can evaluate the color of the liquid. “Yellow” or “Yellow with a hint of green” are the target colors you want to see because they represent 6 to 6.8 ph. If the color is green or blue or aqua, then the ph level is going to be too high and you’ll need to bring it down. Use the “ph” down product or unsulfured plant molasses to lower it. If you go too low by mistake, just pour some of it out and add more water to balance it.


Watering time is also the time you should closely inspect your plant for bugs or diseases like powdery mildew. It only takes 30 seconds to look on top of and underneath the leaves. Always pair watering time with plant health inspection. A plant is not healthy if it has pests like spider mites or aphids, and pest infestations can become crop killers.


How much water should I give to my cannabis plants?

With a 1 gallon pot, it is common to give around 2 – 3 cups of water.

With a 5 gallon pot, it is common to give around 1/2 gallon up to 3/4 gallon (8 cups to 12 cups) of water.

NOTE: It depends on how well the soil retains the water you give it. If most of the water gushes out the bottom or sides of the pot, then you will need to water more!

As plants get bigger, they do require more frequent watering.


When should a home grower water cannabis?

The best time to water cannabis plants is in their morning, an hour after the lights first go on.

Do not water cannabis plants right before lights out / lights OFF.


Use a soil moisture reader: 

The golden rule of watering cannabis plants in soil is to water when the soil is “almost dry.” “Almost dry” is in between “dry” and “moist.” You should use a soil moisture meter to help you make your determination. To use it, just stick the meter in the soil and get an immediate reading. Some soil moisture meters might need to be replaced if they break or are misused, but most of the time you can count on them to work quite well. They do tend to get misplaced, but they are inexpensive to replace. I recommend getting a few of them.

If you don’t use a soil moisture reader, then you’ll need to use your best judgement to determine when it is time to water or not. You’ll accomplish this by assessing the weight of the pot, the feeling of the soil in and on your hands, and the appearance of the plant’s leaves. Leaves wilting, coupled with dry soil and a light pot are a clear indication a plant needs to be watered right away. On the other hand, if the leaves are pointing up and perky, and the soil still feels moist on the sides and at the bottom of the pot, it is an indication the plant does not necessarily need to be watered right away. In a hard plastic pot, it is not really possible to feel the sides and the bottom of the pot, so felt pots are the ideal pot.

To assess the weight, pick the pot up to see if it feels heavy, light, or in between. A light pot is a solid indicator it’s time to water, especially if the leaves of the plant are starting to wilt. After you pick up freshly watered pots over time, you’ll get a strong sense of what is heavy and what is light. The weight of a wet pot is much heavier than an “almost dry” or “dry” pot. If you don’t have a soil moisture meter, make sure you slide your hands down the sides of the pot to feel if the soil is dry, almost dry, moist, or wet.

There is a myth that says if the first two inches of soil are dry, then it is time to water. That is bad advice to home growers everywhere. The problem with that strategy is you can have the first two inches of soil be dry, and the bottom 12″ + be wet or very moist. You can’t rely on the top two inches to tell you what’s going on in the root ball in the soil. That’s why soil moisture meters are excellent tools to use. Also, if the top two inches of soil are dry but the rest of the soil is very moist and the pot is heavy, you can simply “lightly mist” the the dry topsoil with water.

Hands down, the best way to make a quick accurate decision regarding when to water indoor cannabis plants in soil is with the aid of a soil moisture reader. It takes the guess work out!


How to water cannabis plants growing in soil: 

Water gently and slowly. Don’t just dump a bucket of water in the pot and call it a wrap. An important consideration of proper watering is to water slowly. Not only should you water slowly and gently, you should first water slowly around the edge of the pot (while patting the sides of it with your hands if it’s a felt pot or soft plastic pot.) This helps the soil retain the water. After you’ve watered the edges of the pot, then you can slowly water the center area of the pot. Then you can pick up the pot and gently rotate and roll it side to side to encourage the water to flow throughout the soil.


2. Ensure temperature and humidity are in the acceptable range. Check your hygrometer often.

Check the grow tent hygrometer daily, especially at the hottest part of the day. If the temperature is rising above 80 degrees Fahrenheit, then you should take swift action like opening the grow tent doors and putting the lights onto their lowest setting. The best thing you can do is turn on an air conditioner, but that isn’t always possible. You can also blow cool air from the outside in with a fan, or you can exhaust the hot air outside, or both if the exhaust and intake are on separate sides of the room.

Although plants in VEG may grow well in humidity around 70%, when humidity is over 60%, plants actually have a much higher likelihood of getting powdery mildew. In VEG phase, try to keep the humidity between 50 and 55% to avoid powdery mildew from infecting your grow.

Keeping humidity between 50 – 55 % can sometimes be a challenge. To manage the humidity, use an appropriately sized humidifier or dehumidifier inside your grow tent. Sometimes people need a bigger, stronger humidifier and dehumidifier, and so they set them up in the room their grow tent is in, not in the actual grow tent. You might want to do that, if you find it necessary.

Anyone with central air conditioning is going to have the biggest advantage. If you have a portable AC or AC/dehumidifier combo, they also give you an advantage with indoor growing. People without AC are going to have a harder time in the warmer months, but hopefully the tips above will keep everyone growing without interruption. The worst case scenario is that you take the hottest summer months off from indoor growing. If you’re living in a remarkably hot area without air conditioning, that is a smart choice.


3. Ensure good airflow. Utilize one fan to exhaust air and one fan to circulate air inside the grow tent.

This element of maintaining your home grow is on auto-pilot once you set your fans up. One fan will be your exhaust fan suited for one of the top holes in your grow tent. The other fan can be a pole fan, oscillating pole fan, or even a small box fan that sits on the floor as a last result. Just be sure your fans stay on 24/7.


4. Do pest control sprays 1x a week. Apply more often as necessary.

By applying pest control sprays to your cannabis plants each week, you are preventing pest problems. Home growers should avoid pest problems because pest problems can literally ruin gardens in a matter of a week or two. An ounce of prevention is certainly worth a pound in cure in cannabis cultivation.

Sometimes you may get pests in your garden. You could get pest issues even though you’re applying pest control spray 1x a week. If you get some pests like aphids, spider mites, thrips, white flies or scale, or diseases like powdery mildew, botrytis, or blight, then you should adjust your pest control spray efforts from “prevention” to “killing.” Look at the label of the product you’re using to see if there are instructions for prevention vs. killing.

Fungus gnats are the pest that do the least amount of damage. If I were to get one pest, and only one, I’d go with fungus gnats. The worst to get are spider mites, powdery mildew, and botrytis.


5. Do cannabis plant maintenance. “Top” each plant once and “defoliate” & “debranch” as needed.

In VEG phase, it is important to “top” your plant to allow it to grow strong side branches and yield more.

To “top” your plant means to remove the highest, uppermost node of growth from the plant. The top node can be cut off with your clean trim scissors, or pinched off with your fingers. You also can top your plant by cutting the top 1″, 2″, or 3″ (or more) of the plant right from the stalk. As a general rule, “top” after there are at least 4 established node of growth. After you make your cut, just discard the lopped off plant material. A tall plant that needs to be topped should simply be lopped off a few or several inches from the main stalk. Shortening your plant when you top it is commonplace when you’ve got a plant that’s already getting too tall for your grow tent. You don’t want plants growing too tall into the light.

After you “top” your plant, then your cannabis plant will soon explode with growth! It might feel counterproductive to be cutting the top growth off, but it’s crucial to do it. Don’t be scared!

If you’re growing from CLONE, topping is always necessary. If you’re growing from seed, sometimes the side branches grow without you topping the plant.

While it is possible that you can continue to “top” the plant, it isn’t recommended if you want to stay on the 30 day timeline in VEG. Plant need time to recuperate from being topped. You may notice different strains have different growth patterns after being topped. This is to be expected.

Now that you know the term “top” as a verb, it’s time to introduce the phrase “tops” to you as a noun. After a plant is topped, many “tops” are the result. You want as many “tops” as you can get per plant. The “tops” of your plant are the areas of growth where flowers will be blooming in the future. For each plant, you want to be able to count several tops ideally, not just 2 or 3. The tops essentially fill up your canopy – which is your grow space where your biggest buds develop. The tops are the top layer of buds/flowers and are ideally going to form what growers call “cola buds.” Cola buds are flowers densely clustered together.


Defoliate means to remove a leaf, or remove leaves. In VEG phase, you can “defoliate” your plant a little. For all intents and purposes, you only need to remove LEAVES that are blocking new nodes of growth, as well as leaves that are dead or dying. The whole point of defoliating is to allow the light to penetrate your flowers at the top of your canopy. If you find a leaf with many pests or powdery mildew, then carefully remove and discard it. If you leave powdery mildew infected leaves, the infection will spread rapidly, get worse, and never go away.

Some strains are extremely bushy and need more leaf removal than usual. With bushy plants, in order to give the buds and flowers the access to the light above they need, you’ll need to defoliate more than with plants having a sparse amount of leaves. Try not to remove more than 20% of the leaves when defoliating.


Debranch means to remove a branch or branches. The lower branches at the bottom of cannabis plants are not desirable when they don’t grow long enough to reach the top canopy (top layer) of flowers getting quality light penetration. Your trim scissors or harvest clippers can be used to remove the branches depending on how thick or thin they are.

Wait to debranch until after the plant recovers from being topped. Give it a full two or three weeks after being topped to determine which lower branches, if any, to remove. Always cut away, debranch, the lower branches that don’t have a chance to get to the top of the canopy. The plant as a result will focus all it’s energy and growth to the top canopy, which is what you want.

This practice of removing branches from the bottom of the plant is also known as “lollipopping” by many growers. Debranching is specifically for indoor growing where lights are hung overhead. Outdoors you don’t have to do any debranching because the sun rotates and hits the plant at all angles.

Branches down below that don’t get good light penetration wind up producing small, airy, fluffy flowers which growers call “larf,” “popcorn buds” and “undergrowth.”

If you choose not to remove any leaves or branches, your plants will still produce, so technically you can skip all defoliating and debranching and wing it. However, if you want to maximize your yields and not deal with airy popcorn buds and larf, then it is recommended to defoliate and debranch as explained above.


6. Transplant your clones from a solo-cup to a 2 or 3 gallon pot, and to a 5 or 7 gallon pot right before you flip to FLOWER phase.

Remember, you don’t need to transplant when you have seedlings planted in their final pot. Since clones don’t have tap roots, transplanting is necessary. The same technique used to plant your clone is used in all transplanting.

Get the soil completely wet with no dry spots, then place the plant in, cover it and fill it with soil and water it slowly. Before you place your plant in, you can gently tease the roots loose with your finger tips before putting in in the soil. Keyword is GENTLE. Don’t be overly rough.

If the plant being transplanted was “almost dry,” then be sure to water it very well during its transplant. If the soil is very moist, only water it very little during a transplant.

After watering, put the plants up on plant risers so they can drain easily and get airflow to the bottom of the pots.

Around Day 30 in FLOWER, right before you switch the light cycle to 12 / 12 to flip to FLOWER phase, transplant to a larger pot such as a 5 gallon or 7 gallon pot.


The leaves will be green and pointing up “praying” to the light when they’re healthy and happy.

Nothing shows that cannabis plants are happy and healthy in VEG, more than their leaves displaying vibrant green colors and praying (pointing) up to the light. However, just before lights go out, the leaves will point downwards. 


What is the best way to yield more cannabis?

Good quality cannabis genetics are required if you want to grow cannabis that delivers heavy yields. Overwatering and underwatering always lead to weaker yields. You’ve been warned.

One of the best ways to yield more cannabis is to set up two grow tents. You can put your tents next to each other, but they don’t have to be side by side. While one tent is VEG phase (18 / 6) , your other tent is in FLOWER phase (12 / 12). So as soon as you harvest from your FLOWER phase tent, you can immediately flip your VEG phase tent to FLOWER phase, and begin a new VEG phase crop too. Two tents will greatly improve your yields!

To maximize yields in your grow tent, fill out your canopy (the grow space that is your top layer of flowers) with as many tops as you can.

Many growers do not care about weight or weigh their harvests. Instead they care more about having fragrant cannabis that hits them just right. If I were you, I wouldn’t worry about how much you’re yielding per plant. Leave that to the commercial growers who grow for a living and have mastered the art of cannabis cultivation.



Marc Eden’s DIY Cannabis Cultivation Book For Beginners
Published by Green Carpet Growing, Inc.
San Diego, CA 92103
© 2022 Green Carpet Growing, Inc
All Rights Reserved

No portion of this book may be reproduced in any form without permission from the publisher, except as permitted by U.S. copyright law.

For permissions contact: marc(@)