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While all plants share similarities in how they grow, the cannabis plant has its own independent quirks and foibles that set it apart. There are a number of steps you can take during the vegetative stages of growth that will help you later down the road, such as what you feed your plant and when you do it.

During the initial growth period of the plant, it builds up structural integrity (stem and roots). It’s only after that the plant begins to develop foliage. During these early stages of growth, your plant will require a lot of nitrogen supplied to it.

Early leaves will begin the photosynthesis process, absorbing sunlight and furthering the plant’s growth. After your plants have germinated and begun to stabilize, consider taking out any late-germinating seeds or stunted seedlings. That way these won’t compete with your other plants for light and nutrients.

Once your cannabis plant has a stable root system and the environment is set up properly, it should just be a matter of upkeep to make sure you end up with a good yield. The plant will continue to grow and develop given proper nutrients and light, developing a strong structure necessary for the flowering phase.

As the plant continues to develop and mature, it will require additional fertilizer, water, light, and higher levels of carbon dioxide in the environment. It will also require more nitrogen. You want to make sure you’re providing for all of the plant’s needs.

In this article, we’ll talk about cannabis seedlings, the vegetative phase, and how to manage foliage development. It’s all about maximizing growth in this vulnerable early phase and making sure you keep your plant healthy and strong right up to the home stretch.

The first leaves

The leafy foliage of the cannabis plant grows in a series. Every series produces a certain number of leaves. Generally, the first series produces a single leaf. The second series will put out three leaves, the third series will produce five leaves, and so on.

The number of leaves produced in a single series usually caps out around ten. You may sometimes see leaves referred to as ‘lamina’ in growing literature.

First leaves - day 12
First leaves – day 12

After about two to three weeks of growth, your cannabis plant should have experienced about 5 or 6 different rounds of growth. You should be producing a regular and steady amount of leaves with every new series. You’ll also notice that the branches are beginning to develop and expand outward.

Feeding seedlings

You’ll want to make sure your young cannabis seedlings get lots of nitrogen early on in their development. Using fertilizers comprised of worm meal, blood meal, or bat guano will help you get the nutrients you need from natural sources.

Fertilizers for growing your plants
Fertilizers for growing your plants

Other options include various algae compounds, nettle blends, or fish compounds as your organic fertilizers. There are several factors that make organic fertilizers a better choice for growers than chemical fertilizers. One of the major reasons it’s better is that it can be very easy to overfeed your plants and damage them when using powerful chemical fertilizers.

When the first leaves pop out, you’ll want to measure the electrical conductance of your nutrient solution. You want to measure very close to 1 at the beginning. As the plant grows and matures, it’s ok for the electrical conductance to be raised up higher. When a cannabis plant has at least 4 or 5 different levels of foliage, you can raise the electrical conductance up again, to about 1.5.

Tip: make sure to download my free Grow Bible for more information about vegetative stage

Once branches begin to develop on the plant, you can raise the electrical conductance up to about 2, but be careful about too much nutrient solution and water. Overwatering your plant can cause it to grow more in the stem then the buds, which is counterproductive for most growers.

Allow your plants root systems to air out and rest between irrigations. Remember to start adding plenty of nitrogen to your plant as soon as the first leaves develop, but make sure you are keeping the electrical conductance at around 1 to start with.

Environmental factors

The rest of the environment is also something you want to make sure you are optimizing throughout every stage of growth, but particularly during the early phases. You have a couple options when it comes to lighting.

After your plants get past the seedling stage, you can expose your plants to light for a full 24 hours, but it’s better to simulate night and give the plants up to six hours of darkness every 24 hours. You’ll want sodium vapor or metal halide type lamps to make sure you’re providing the right kind of light.

“Vegetative growth is maintained by giving plants 16-24 hours of light every day. Unrestricted rapid vegetative growth is the key to a heavy harvest.”

Jorge Cervantes
Important environmental factors Temerature & Humidity
Important environmental factors Temerature & Humidity

Keep the air temperature in your grow room somewhere between 68 and 78 degrees Fahrenheit. The roots should be slightly cooler, around 65 degrees Fahrenheit. Despite this, make sure the soil is warm enough, especially early on. If roots don’t develop properly, the rest of the plant will not either.

Don’t forget to measure the humidity in the room as well. This will affect the efficiency of your plant’s respiration, and also the early health of the plant. You want the humidity in your grow room somewhere between 50% and 70%. When the plant matures, it will be less sensitive to humidity.

Tip: make sure to download my free Grow Bible for more information about temperature & humidity

Controlling these environmental factors will help optimize your plant. However, genetics still play a huge role in determining how the plant develops, and what sort of yield you’ll get. Even if everything is perfect, you can’t turn bad genetics into a great product. Still, if you are meticulous and careful throughout the cannabis cultivation process, you can always optimize the plant, however high its potential yield might turn out to be.

Vegetative stage

A good growth period will be followed by a strong flowering phase. As a grower, it’s your job to get your plants everything they need to develop properly before they flower.

This means healthy foliage, a tough structure to cope with the weight of heavy buds, and a strong root system. Keep an eye on the light, nutrients, carbon dioxide and temperature of your grow room throughout the process.

Watering during vegetative stage is very important
Watering during vegetative stage is very important

Especially during the vegetative stage of growth, be careful when irrigating and watering your plant. As the plant grows larger and larger, it will require more water to keep up with the development.

This means it’s easy for the plant to become dehydrated at this point. Watch out for curling or yellowing in the leaves, and monitor the electrical conductance of your nutrient solution if you’re implementing a hydroponics system in your grow room.

Temperature, humidity and nutrients

Once your plants hit the peak of their growth phase, you can expose your plants to light for a full 24 hours, but it’s better to simulate night and give the plants up to six hours of darkness every 24 hours You’ll want sodium vapor or metal halide type lamps to make sure you’re providing the right kind of light.

Keep the air temperature in your grow room somewhere between 68 and 78 degrees Fahrenheit. The roots should be kept at a slightly lower temperature, around 65 degrees Fahrenheit. Despite this, make sure the soil is warm enough, especially early on. Remember, your roots need to develop properly for the rest of the plant to.

Metal halide lamp

Don’t forget to measure the humidity in the room as well. This will affect the efficiency of your plant’s respiration, and also the early health of the plant. You want the humidity in your grow room somewhere between 50% and 70%. When the plant matures, it will be less sensitive to humidity.

Keep adding nitrogen, too! You want the electrical conductance to measure somewhere between 1.5 and 2. If you are using soil, make sure to continue adding liquid fertilizers and monitoring the moisture in the soil.

Determining sex

There are two commonly utilized methods of determining gender in Cannabis plants. Gender is definitely something you want to be certain of because mixing male and female plants in your grow room has the potential to ruin your crop.

The first method for determining gender is to carefully examine the 5th series of leaves on your plant. You’ll want to do this right before the plant should flower. Indicas and hybrids with Indica genetics will display their sex between the leaves of the plant right before they flower.

Determine sex during vegetative stage
Determine sex during vegetative stage

If you look very carefully, you should be able to see a tiny white fiber if the plant is female. If the plant is male, it will have a small ball instead of a fiber or tendril. This method is easy, but it’s not the most reliable, and sometimes it’s very difficult to find the developed sex organs on the plant because they are so small.

TIP: Looking to buy seeds? Visit the ILGM seed shop

The better method is to take cuttings. Once your plant is in the vegetative stage, you can take cuttings from the plant and root them in another room. Expose the newly rooted cuttings to 12 hours cycles of light and darkness. The plants should flower within several days. If any of them are male, you’ll want to remove them from the grow room.

Forced flowering

After you’ve gone through and made sure that you don’t have any male plants in your grow room, make sure you’re ready for the next stage of growth: flowering. Set all the plants up neatly and double-check to make sure they aren’t fighting over any sources of light.

Keeping your plants well spaced is a good way to help ensure a healthy yield. Double-check the roots to make sure all the plants have enough space below the surface as well.

Vegetative stage into flowering stage
Vegetative stage into flowering stage

If you need to transplant your Cannabis because the root system has grown too large, now is the time to do it. Root systems expand rapidly during the vegetative stage of growth. You need to make sure the plant isn’t suffocating. If it can’t pull up and absorb the nutrients it needs, it won’t do well during the flowering phase.

Night and day

You can force your plant to flower by adjusting the light cycles in your grow room, mimicking a change of seasons. You’ll want “shorter” days, with roughly 12 hours of light exposure followed by 12 hours of darkness. The easiest way to manage these changes in the light cycle is to use an automatic switch that turns your lights on and off at the required intervals.

12 hours of light - 12 hours of darkness
12 hours of light – 12 hours of darkness

Make sure that you stick to these cycles once you start. All it takes is a single exposure to light during one of the cycles of darkness to interrupt your flowering. If the flowering cycle is interrupted, the plant might start growing again.

This sort of stress is bad for the health of the plant, and it can result in reduced yield and unpredictable side-effects. If you do mistakenly expose the plant to light during a cycle of darkness, try to repeat the process again, and this time don’t interrupt it. Don’t be tempted to look in on your plant while it’s “night-time”!

Tip: read everything about the seedling stage or flowering stage

Thanks for reading. Please leave comments or questions below and don’t forget to download my free grow bible

Robert

The founder of I Love Growing Marijuana, Robert Bergman, is a marijuana growing expert that enjoys sharing his knowledge with the world. He combines years of experience, ranging from small-scale grows to massive operations, with a passion for growing. His articles include tutorials on growing... [read more]

68 Comments

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  1. By Ken

    ,09 Jun 2015
    Wow! These are all great articles. Thanks ILGM.
  2. By lee&jo

    ,20 Jun 2015
    can i re-pot my plants, 1st stage of flowering ?.
  3. By latewood

    ,24 Jun 2015
    Lee&Jo, Not sure what you mean by 1st stage. how many weeks into flower are you? I have re-potted in flower, but I carefully remove plant, and place it gently in new pot. New soil can encourage more root growth. […]Read More
    1. By Corwizz

      ,28 Aug 2018
      The thing with re potting and the soil content is the bacteria, just like in a fish tank... re - potting during the vegetative stage is fine, however if your doing it during the harvesting stage your most likely going […]Read More
  4. By MJCTHC1

    ,01 Aug 2015
    I have noticed that a lot of information on this site is contradictory due to language barriers and typo's, I feel a proof reader is required to make this site even better than it is. A good example is when […]Read More
    1. By Mags

      ,03 Dec 2016
      Your punctuation needs some work.
      1. By me1333

        ,08 Jul 2017
        dude is obviously hight as hell, he repeated the same paragraph lol
    2. By Corwizz

      ,28 Aug 2018
      Bad example: next time paraphrase what had been said then try to explain it in your own words... the english language is fucked up when coming from another language/country.. and to be honest - maybe it may not make any […]Read More
      1. By Deez nutz

        ,14 Jan 2019
        "I'm a grammatical assholes most of the times..." sound like you needed to proof read a little better.
  5. By When And How To Transplant Marijuana Plants

    ,18 Aug 2015
    […] they have an established, sturdy root system in place. The plant is ready to focus its energy on vegetative growth now, so it needs to be moved to a better location for such a task. You will need to […]Read More
  6. By The Life Cycle Of Marijuana Plants

    ,24 Aug 2015
    […] of absorbing and processing a much higher amount of carbon dioxide and other nutrients. During the vegetative stage of growth, the roots will continue to expand and the plant will grow taller. This is the point at […]
  7. By J milam

    ,29 Sep 2015
    Good info on veg state article. I'm sure I'll be reading more, thanks
      1. By Mike H

        ,26 Aug 2018
        So I started growing 2 plants, in early August, outside, in Wisconsin. I know I'm way late on the growing season, but plan to move them indoors, with artificial light. Any suggestions???
  8. By Justin

    ,22 Oct 2015
    Please help my plants not doing well the under leaves are yellow n I lost two of the bottom leaves my temp is 81.1 humidity is 52 the soil level is ph 4 phosphorus is 5 potassium is 6please help
    1. By rickielei

      ,18 Feb 2017
      PH should be 5.5 - 7 on average 6.5 is your goal
    2. By aj

      ,16 Aug 2017
      Nitrogen(bloodmeal) very important, it will fix a lot of problems, knats, keep top layer of dirt dry, knats love laying eggs in damp moist dirt, I layer pepper mint leaves over soil, plus its probly good for soil
  9. By latewood.ILGM

    ,22 Oct 2015
    Without more information it is hard to give you an informed answer. Please join our Support forum, and some of our many members and expert growers, will be able to help you out. :) When you join, look in beginners […]Read More
  10. By Stop Nitrogen Deficiencies In Marijuana Plants Now!

    ,24 Nov 2015
    […] notice your plant is losing lower leave quickly because of the yellowing, particularly during the vegetation stage, you have an issue on your hands that requires and immediate […]
  11. By Mark

    ,23 Dec 2015
    Hey my name is Mark and I wanted to know how can you tell the sex of a plant if its 2 1/2 weeks in veg?
  12. By Thomas De Costa

    ,28 Feb 2016
    How are to you, I've requested several times for your free grow bible, I still haven't received it, ?? HAPPY GROWING.
    1. By Jennifer ILGM

      ,01 Mar 2016
      Hi Thomas, all grow guides will be send to you when you start the download here: http://ilovegrowingmarijuana.com/marijuana-grow-bible Contact support if your having download problems.
  13. By Dennis

    ,26 Mar 2016
    I have 4 White Widow plants growing under lights. They are still only 3 - 4 inches tall, very leafy and green but I'm thinking they should be double the size by now ? I am using a 4 ft. […]Read More
    1. By Brian

      ,24 Jan 2017
      Makesureyoure led lights are at a lux of about 4500 5500 during seedling/veg then 6500 during flower. Blue light spectrum to red light spectrum...get it?
    2. By Joel

      ,27 Mar 2019
      Miracle grow is not that good for marijuana plants...it is a slow release fertilizer.
  14. By John

    ,24 May 2016
    Robert love the site seeds and info. However I have tried multiple times to download the grow bible and have had no emails received or success to the download.
  15. By Duane.

    ,09 Jul 2016
    Great read. Guys and gals know your junk..and grass. Thanks!
  16. By William Marshall

    ,21 Jul 2016
    Can a plants night cylce be interrupted in veg stage with no side affects?
  17. By latewood.ILGM

    ,22 Jul 2016
    William, It all depends on how long the dark period was interrupted. But most likely nothing will happen. If the lights were left off for 2 long this could have an affect on the plant but, leaving the lights on […]Read More
  18. By Enrique Ramos

    ,29 Jul 2016
    Thanks for all the info, I am a new grower and I was lost until I found this site, thank again.
    1. By Roy ILGM

      ,01 Aug 2016
      Good to hear Enrique! If you like you can kick it with other growers on the support forum!
  19. By Brandon Medlin

    ,01 Sep 2016
    I'm using a 65w T5 light for verging. With 5 plants. Is that enough light... First time grower
    1. By latewood.ILGM

      ,05 Sep 2016
      Brandon. I am not sure how much light penetration you are going to get once the plants start bushing out. I suggest you join our support foerum. We have many experienced growers there willing to help :)
  20. By Tina

    ,05 Sep 2016
    Hi guys, i just want to know if two 18w 2 feet fluorescent uv lights can be used in the vegetative stage. this is our first grow and after putting this uv light, with a few LED red and blue […]Read More
    1. By rebelx59

      ,29 Oct 2016
      I veg for 6 weeks, as a general rule of thumb.
      1. By Marissa

        ,18 Feb 2018
        THANK YOU that is super helpful nowhere in the article did it say how long to keep in veg. state for.
  21. By latewood.ILGM

    ,05 Sep 2016
    Tina, You really need to join our forum. The blog is not set up for wholesale grow support. More simple Q & A. A 2 foot fluorescent is good for propagation and early vegetation only. Happy growing.
  22. By patty

    ,25 Mar 2017
    How long can you stay n veg., before going into flower? First time grower. I have some n flower and next run in veg... Think I jumped gun. Veg will last 6-7 weeks til flower stage ends. Help
  23. By D-ROCC

    ,01 Jun 2017
    My leaves keep dieing they keep curling up turning yellow or yellow on the tips and it spreads on the leaves or the leaves get brown spots on the leaves.....what am I doing wrong.....this is my first time growning......
  24. By brad

    ,20 Jun 2017
    I m having the same problem D-ROCC, I ma first time grower,outdoors.Trying to do everything right , but just don't seem to be working out.
    1. By Roy ILGM

      ,21 Jun 2017
      Hi Brad, be sure to hop onto the support forum. Our experts there are very open to help starting growers – I❤️GM
  25. By Twlnhd

    ,26 Jun 2017
    I'm into a flowering stage for several weeks now is there a way I can return her to a vegetable stage?
    1. By Mr. Grey

      ,04 Nov 2017
      You can absolutely put the plant back into veg, it's never too late. Just remove any "buds" and put it back to 24h light for a week, then 18/6 again. Takes a few weeks and will be good as new. […]Read More
  26. By latewood.ILGM

    ,10 Jul 2017
    Twinhd, After several weeks in flower it is not advisable to re-vegitate your plant. However; I f you decide to do so, just place the plant back into 18 or more hours of light. The plant will stress for 1-2 […]Read More
  27. By RTM

    ,14 Dec 2017
    i have been growing northern lights for 2 months now, there are some great leaves coming in on top of the plant which is now 4 to 6 inch's tall. My concern is that the main stalk is pretty skinny […]Read More
    1. By latewood_ILGM

      ,18 Dec 2017
      RTM, I am not trying to be rude or to insult you (it is not our way...) but, if you have a plant that has been in vegetative cycle for 2 months and it is only 4-6" tall; You are […]Read More
  28. By wiffin

    ,31 Jan 2018
    hi can some1 tell me how come some my plants are smaller than others is dat nomal some are a lot smaller and what do I do to make it up do I just leave den or give den something. […]Read More
  29. By wiffin

    ,01 Feb 2018
    and also is it ok to giv them freezing water? dats wa av been doin jus cold water out tap 80percent dem looking good . thanks
    1. By latewood_ILGM

      ,18 Apr 2018
      Wiffin, Hard time making out your language but, here goes. No freezing water. Water temp need to be between 65-70f 68f is optimum for oxygen retention. You can switch to whatever nutrients you want as long as they work. If […]Read More
    2. By latewood_ILGM

      ,28 Aug 2018
      Sorry for the really late reply. Never saw this. I suggest you join our forum, if you haven't. No. Do not shock your roots with freezing water
  30. By Earl Myrtue

    ,30 Apr 2018
    just set up indoor room with 4=2000 watt LEDs and the plants are about 1 month in veggie cycle.How long should I keep them in this cycle?
    1. By latewood_ILGM

      ,23 May 2018
      Earl Myrtue, 1 to 2 monrhs
  31. By wayne

    ,23 May 2018
    hey all a friend gave me 6 bag seeds all are coming along fine i have a aerogarden to start them with. i topped he 4th node and again at the 4 node which made 6 0r 8 stuck them […]Read More
  32. By latewood_ILGM

    ,23 May 2018
    Wayne, I think you should join our forum. support.ilovegrowingmarijuana.com I am sure you will get a good exchange of info there :)
    1. By wayne

      ,26 May 2018
      thanks bud i will join cheers
  33. By james

    ,08 Jun 2018
    my seeds have germinated and I have planted them in small containers my question is since I live in South Texas where the temperatures always get in high 90s and we are all ready experiencing temperatures in the low 100s […]Read More
  34. By latewood_ILGM

    ,13 Jun 2018
    kames, You do not want the roots exposed to heat. I would use cloth pots, dig a hole and use the cooler dirt in the hole to shelter my root zone ion the pot. I also recommend for outdoors western […]Read More
  35. By mark$

    ,12 Nov 2018
    my plants are 6 weeks old 3 feet high ig grow tent when should they be out of veg, and put into flower stage help firstimer
  36. By Destiny

    ,30 Jan 2019
    My amnesia haze is taking longer to sprout a taproot I'm five days and
  37. By Priscilla Simonsen

    ,20 Feb 2019
    Trying some White Widow Indica seeds this time. Seems to be taking longer tho get to flowering stage than my previous plants. Is this an Indica thing??
    1. By latewood ILGM

      ,25 Feb 2019
      Flowering indoors occurs when you induce flowering by changing the photo period from 18/6 to 12/12. Simple as that. Feel free to join our forum where we can help guide you through your grow successfully. Happy growing, :)
  38. By Jim firth

    ,12 Apr 2019
    I love weed and my penis is nice

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