What to expect when your cannabis plant is in the Vegetative (veg) Stage.

by Alex Robles

     Take a moment to pat yourself on the back because that seedling you agonized over is now a plant in the vegetative (veg) stage.  Most new growers usually make mistakes and their plants pay with their lives before they get to veg.  So again, good job on getting your plant this far.  Now that we’re done celebrating we have to plan our work and work our plan because that plant is going to need more of our attention now. 

     I’m going to talk in some broad general terms about the cannabis plants.  The reason for this is because there’s so much variety in cannabis, it’s easy to get tangled up in the small details.  Before we start talking about the veg stage, the importance of pH, nutrient needs and pest control, let’s get to know this amazing plant a little better. 

   The Cannabis Plant  

     What does it mean when we say that cannabis is a “photoperiod plant”?  Here’s the simplest way I can explain it, the length between the day and night hours of a day is known as photoperiod or light cycle.   Some plants and flowers need a certain amount of sunlight to trigger their flower stage, that’s how we get the seasonal blooming of flowers.  When cannabis is grown outdoors, it moves through its different stages of life and maturity depending on the seasonal photoperiod or light cycle.  The cannabis plant needs at least 16hrs of light to stay in vegetative stage but 18hrs of light is the industry standard for keeping all varieties of cannabis in veg.  You can veg your plants under 24hrs of light and get great results but I like to let my plants rest since they are alive

     The next thing we need to understand is that cannabis is an annual diecious plant.  That’s a mouthful, but here’s what that means.  An “annual plant” will complete its life cycle within one growing season.  For cannabis that is usually from spring planting to the fall harvest.  It’s also a “Diecious (dī-ē′shəs)” plant, which means the male and female reproductive organs are on separate plants rather than different parts of the same plant.  You see, most flowering plants, shrubs and trees have both male and female flowers on the same plant.  This makes it easier for pollinators like butterflies and bees to move the pollen from the male flower to the female flower that could be right next to it.  Other flowers and fruiting trees have only male or female flowers on a single plant.  Which means gardeners, growers and cultivators need to plant male and females close to each other to ensure pollination.  Cannabis is diecious because you need the pollen from the male plant to pollinate the flower of the female plant to make a seed.  There is also the possibility of stress-related sexual changes that could cause hermaphroditic varieties that will have both male and female reproductive organs on the same plant (gynodioecious gahy-noh-dahy-ee-shuh s).  This is one of those details I don’t want to get wrapped up in.  It typically doesn’t happen with plants outdoors unless you’re trying to manipulate the light cycle.

Sex is always important

     Now let’s talk about why we want a female cannabis plant and what “Sinsemilla” means.  The word “sinsemilla” is a Spanish word that translates to “without a seed”.  Females plants without seeds are known as sinsemilla and they’re the plants that are the one most sought after by growers because of their high trichome (oil/resin gland) content.  Those trichomes are the resin or oil glands that contain the active medicinal cannabinoids like THC and CBD.  They’re also what gives cannabis buds that frosty almost powdered sugar look.  When we keep the females unpollinated, she will produce more flowers (buds) and more trichomes.  Which means you get a more potent flower at harvest time.  When a female plant gets pollinated, instead of using its energy to make buds and  trichomes, it uses its energy to make seeds.  

     The female reproductive organ is known as the Pistil and coming out of the Pistil are two hair-like structures called the Stigmas.  These hairs are responsible for taking in male pollen to make a seed.

   Growers Note:  Cannabinoids are natural chemicals produced by the cannabis plant that interact with your cognitive and physical functions to produce altered states of mind and being. 

Sativa and Indica

  Indica and Sativa are the names of the two main varieties of marijuana that are best suited and the most popular for medical and recreational use.  The “Ruderalis” variety is used to make a boutique variety of cannabis known as “Autoflower.  Now depending on who you ask or what book you read Indica and Sativa are either two different varieties of marijuana or two different mutations of the same strain.  Ruderalis on the other hand is closer to a hemp than it is to a drug variety of cannabis but it does have some interesting qualities.  Here are some other characteristics for these strains.  

   Sativa:  This variety originated in the humid tropical regions of South and Southeast Asia, North Africa, Central and South America.  This plant strain is tall and will typically get between 8 and 10ft tall but has been known to grow up to 20ft in one season when it’s grown in the ground.   They will have less bushy branches, with skimpy leaves that help the air to flow around and through the plant.  This air flow helps promote healthy growth and lessens the risk of fungus development in the humid climates that they originate from.   The leaves are long, thin, and narrow and are usually a lighter color green than its Indica.  The high from Sativa flower is typically described as being felt mostly in the brain. It’s been described as being more hallucinogenic than an indica high.  I like using Sativas during the day and to celebrate with.  Some of the best known varieties of Sativa are the Haze family, Durban Poison and Trainwreck

   Indica:  This variety originates from the regions of the Middle East and parts of Asia.  Since it comes from these harsh mountain climates, it can easily adjust to the drastic temperature swings of hot and cold better than its Sativa sisters.  Indica’s are shorter, wider plants that will usually grow to be 4 to 6ft tall.  What they lack in height they make up for in dense, bushy growth.  These strains will produce more side branches and be bushier than Sativa and the leaf is shorter with wider blades and are often a darker green than a Sativa leaf. The smaller size of this strain makes them popular with indoor growers where space is always an issue.  The high from Indica flower is typically described as relaxed and sedative, often described as a “body” high.  I will typically use indicas at the end of my day, when I’m ready to wind down.  Some well known varieties of indica are the OG Kush, GrandDaddy Purple, Afghani 

    Hybrids are just that, a combination of any of these three strains.  Typically you’ll see advertisements for seeds or flowers (bud) that say ” Indica or Sativa dominant”.  That just means the plant shows more of those characteristics.

    For more detailed information about India and Sativa please visit the link.  https://wordpress.com/post/inmygrow.wordpress.com/315.  Also check out Ep. 110 of the “In My Grow Show”. https://inmygrowshow.libsyn.com/ep-110-cannabis-garden-101-indica-sativa-and-ruderalis 

The Vegetative Stage

    The vegetative stage is the main growing phase of the cannabis plant.   This is when it starts to make leaves and branches at a steady and regular pace and it’ll start to get taller and wider.  The fan leaves will get bigger because they’re trying to absorb as much sunlight and CO2 as they can.  Those stems and branches will thicken up as the plant moves through the veg stage preparing for the weight of the flower (bud).  The root system will also begin to spread out in search of food and water.  Don’t forget, as far as light goes, the cannabis plant needs at least 16hrs of light to stay in vegetative stage.  18hrs of light is the industry standard for the most part.  You can veg your plants under 24hrs of light and get great results but I like to let my plants rest since they are alive

     I will usually start germinating my seeds in mid to late May so they’ll be ready to be outside by mid to late June.  If I’m buying clones for the outdoor season, I won’t pick them up until late June.  

 Growers Note: It always helps me as a cultivator (grower) to do my research on the strain that I’m growing.  That way I’ll know what to expect and the best practices to use when growing it.  I have no problem getting on the internet and asking fellow growers that I respect about it.  This will also make growing it a lot easier, more fun and interesting.  If it’s a mystery clone or seed, I’ll educate myself on the different characteristics of the Sativa and Indica plant and how hybrids work.

   Why pH your water?

    Next, let’s talk about water pH again because it’s that important.  Every animal and plant on earth needs a balanced pH that is perfect for them in order to thrive.  As humans we enjoy an average pH of 7.4.  Cannabis is no different, if their pH is off then the plant won’t absorb nutrients correctly.  The pH scale goes from 1-14 and is a way to measure how acidic or alkaline/base a liquid, mixture, or solution is.  A pH of 1 means that the mixture is highly acidic and a pH of 14 means the mixture is highly alkaline and a mix that is pH neutral will be a 7.  All of the primary, secondary, and micronutrients, with the exception of molybdenum, are best absorbed when the solution has a pH of 5.5 to 6.5.  Anything higher or lower than this will make the marijuana plant struggle to take up nutrients and could easily cause a nutrient deficiency along with other problems.  Personally, I don’t like to go lower than 5.5 or higher than 6.3.  More pH information and a pH chart can be found at the following link. https://inmygrow.wordpress.com/2016/08/25/a-healthy-marijuana-plant-needs-ph-balanced-water/ 

Nutrient needs

Almost all plant life uses the primary/macro nutrients of nitrogen (N), phosphorus (P), and potassium (K) as the major building blocks for developing a strong, healthy root system and beautiful green foliage.  They are known as macro nutrients because they’re needed and used in large amounts.  But different plants take up these nutrients in different ways at different times in their life cycle.  Plants like vegetables and cannabis will absorb certain nutrients easier when they’ve been processed by bacteria.   This is what your plant is doing with those macronutrients.  For more information about micro and macro nutrients go to this link: https://inmygrow.wordpress.com/2016/08/16/cannabis-nutrients-part-one-primary-and-secondary-nutrients/   

  • Nitrogen (N)

It is used to make the chlorophyll that give leaves their green color, which is an essential part of photosynthesis.  N will be used in large amounts during vegetative growth to help develop a strong and healthy system of roots, stems and branches that will support the dense, heavy flowers (buds).  For more information go to this link: https://inmygrow.wordpress.com/2016/08/22/cannabis-nutrients-part-two-why-does-marijuana-need-nitrogen-n/ 

  • Phosphorus (P)

it helps the plant change the energy it gets from the sun into sugars.  These sugars will make the different chemical compounds used in root, leaf and stem growth, but it’s a vital part of dense bud development during flowering.    Phosphorus will also help the plant cope with the stress of drought, frost, pests, and disease easier.  For more information go to this link:  https://inmygrow.wordpress.com/2016/09/11/cannabis-nutrients-part-three-phosphorus-and-marijuana/ 

  • Potassium (K)

     It lets the plant metabolize (chemical digestion) those carbohydrates (sugars) to make different proteins and amino acids that are used in different plant processes.  Potassium helps carry water throughout the plant and this allows it to be less stressed during dry periods and improves the plants resistance against frost by working in the plants sap.  It will promote consistent, even and strong growth and when combined with Phosphorus it will also help strengthen the root system.   Potassium is needed during flowering to increase the density, weight and number of buds.  For more information go to this link: https://inmygrow.wordpress.com/2016/09/19/cannabis-nutrient-part-four-potassium-and-marijuana/ 

Pest Control

     When I talk to the experts at my local insectary (Rincon-Vitova Insectary) about what home gardeners can do to increase the numbers of beneficial biological predators in our gardens.  The most basic advice that they emphasize is to plant lots of colorful flowers.  Some predators will be attracted by the vibrant colors or the pollen that flowers produce.  The goal in my garden isn’t just to attract the predators but to also have them lay eggs and colonize.  Predator colonization benefits us by giving our gardens some natural biological pest control at very little cost.  Also, some predator larvae are more voracious hunters than the adults.  That’s why in my garden you’ll always find a row or patch of wildflowers growing.  I like to use a wildflower seed mix that can tolerate the heat and drought of my California summer growing season.

     You can listen to an awesome conversation I had with Kyra Rudd from Rincon-Vitova Insectary on Ep. 140 of the “In My Grow Show”, about biological predators in our gardens.  Click here https://inmygrowshow.libsyn.com/ep-140-kyra-rude-from-rincon-vitova-insectary     

     In the late spring, around the end of May and early June I will release two different kinds of biological predators and those are the Green Lacewings larvae and Neoseiulus Californicus (N. californicus).  Releasing them during those cool spring temperatures gives them a chance to colonize in my garden before the hot summer temperature starts.  When the summer temps start to climb and reach 85-90 F most predation or predator activity slows down or stops.         

     Green Lacewing larvae are great general predators that are also inexpensive.  This beneficial predatory will attack insects and insect eggs, like aphids, small caterpillars, mites, Whitefly, scale, Mealybug, Thrips, psyllids, and other soft-bodied insects.  The best temperature range to release them at is between 67 to 89°F (19-31.6°C) and above 30% relative humidity. 

     I like using Neoseiulus Californicus because they’ll go after pests like Spider mites, Persea mite, Avocado brown mite, Tumid mite, Broad mite, Cyclamen and others.  I really like having  them in the garden because they’re active in low and high temperatures of 50°-105°F. 

     Neem oil is a naturally occurring pesticide found in seeds from the neem tree.  It’s a very good preventative, low impact insecticide and fungicide that’s safe to use around us and our pets.   Neem works by stripping the waxy protective layer off of insects, but it will also strip the waxy layer off of leaves if I use it too often or make the mix too concentrated.  That’s why l apply it every 10 day as a preventative measure.  I don’t apply neem oil foliar spray when the plants are in direct sunlight because they will burn.    Here’s how I make 1 Quart of Neem oil spray:


  • 1 teaspoon Neem oil (100% Cold Press Neem Oil)
  • 0.25 teaspoon liquid dish soap (Castile soap is preferred)
  • 1 qt Warm Water
  • Pour into spray bottle

Growers Note:  I don’t apply ANY foliar spray on my garden in direct sunlight.  The droplets that may be on the leaves could act like tiny magnifying glasses and leave little burn spots on the leaves.  If the damage is severe enough it could interfere with photosynthesis.  Don’t apply any foliar spray during flowering also.   

      There’s a lot more nutrients, pest control and general grow knowledge at Inmygrow.com and on the podcast “In My Grow Show” (https://inmygrowshow.libsyn.com/).  

                                   Just as a reminder, always Grow Learn and Teach.

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