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When your marijuana plant is a seedling, it is in its most important and most vulnerable stage of life. This means you will need to be well acquainted with the potential problems that could occur so as to ensure a healthy beginning and future of your plant’s life.

‘Water and heat are critical at this point of development. The new, fragile root system is very small and requires a small but constant supply of water and warmth.’ ~ Jorge Cervantes

The most common seedling are overwatering, underwatering, nutrient problems, temperature, and lighting issues. These are all preventable conditions that an educated or experienced grower will effectively avoid, but as a new grower you can also prevent them from occurring just by doing your homework.

Overwatering seedlings

Overwatered Marijuana Seedling
Overwatered Marijuana Seedling – Image Powered by growweedeasy.com

Although we refer to it as “overwatering,” the problem itself comes from a lack of oxygen rather than an overabundance of water. Hydroponics systems, where plants are literally “planted” in water, work perfectly fine as long as there is enough dissolved oxygen in the water. If you are growing your seedlings in a container as many growers do, overwatering can be seriously risky to your marijuana plants. You will know your plant has been overwatered if it is drooping but not wilting.

If your little seedling is in a large pot, the chances are good that you are going to have an overwatering problem. Seedlings don’t absorb very much water, and a large container requires lots of time to fully dry out. Instead of planting your seedling in a large container from the beginning, start it out in a smaller container until they have grown significantly. You can then transplant it to a larger container.

If you don’t have a choice any longer because the seedling is already growing in the large container, then you are going to need to adjust your watering method. Simply water the plant a small amount of water, and pour it over the seedling in a circle pattern. Makes sure the top inch of soil (up to your first knuckle) is totally dry before you water the next time. Don’t worry about water runoff with a small seedling until it has grown significantly. Your plants will actually grow faster if they are put in a smaller pot, so make sure you are choosing a pot that is the best size for them and then transplant as they increase in size.

Download my free marijuana grow guide at this link for more about watering

That being said, it is also not helpful to have a large seedling in a pot that is too small for it. This is more about the size of the root system than the size of the plant above the soil. Your seedling might become root bound (when the roots have wrapped themselves around the outside of the container, therefore not allowing water to escape through). Root bound plants often exhibit strange symptoms, including drooping and nutrient deficiencies, but also strange and unpredictable ones like interesting patterns of discoloration.

Often drainage (or, rather, a lack of drainage) is the problem when it comes to overwatering. If the water is unable to move freely through the soil and out the bottom of the container, you will run into overwatering health problems. Soil that is clay-based will not allow water to move freely through it, so avoid this type of soil when choosing your planting mix. You should also make sure that there are enough drainage holes at the bottom of whatever container you are using, and that these drainage holes are not jammed or clogged and therefore preventing proper drainage.

Perhaps the simplest cause of overwatering to fix is watering too frequently. You need to allow the soil to have enough time to dry, so as to give your roots an adequate and consistent amount of oxygen. Oxygen in water is absorbed rapidly by the roots, meaning they will also need to have pockets of air within the soil to survive. If you choose a lighter, more airy amendment for your potting mix (such as Perlite), it will retain more oxygen than a thicker or heavier soil. You can add as much as thirty to forty percent Perlite to the mix to ensure maximum oxygen retention.

Another way to increase the amount of oxygen in your soil is to use containers that allow air to come in through the sides as well as the top. Smart Pots or Air Pots are examples of such containers. Another way to combat overwatering issues is simply to water your plants less than normal during colder periods of temperatures. Their growth, processes, and water intake all slow down at lower temperatures, so don’t forget to adjust accordingly.

Underwatering seedlings

Seedling Underwatered
Seedling Underwatered – Image Powered by growweedeasy.com

Symptoms of underwatering include wilting, improper growth, and a lack of moisture in the soil. Although it happens less often than overwatering, it is still a serious problem that could negatively impact your seedling. It happens especially with beginners who have been warned – ‘never overwater your plants,’ so they overcompensate in the opposite direction.

If you combine underwatering with an overdose of nutrients, it will cause the seedlings to turn dark green, stunted, twisted, and new growth will be discolored.

Because there is a constant water loss in plants’ leaves through the transpiration process, they need to always have some presence of moisture to ensure proper functions and processes. If the roots can’t absorb any water, the plant processes will simply stop, and the growth will be significantly slowed or stopped. If roots are ever allowed to fully dry out, they will actually begin to die.

Download my free marijuana grow guide at this link for more about watering

While it’s a less common problem than overwatering, underwatering can be far more serious when it comes to negative health effects. If you look at the soil and you see that it has begun to separate from the container, this means that it is far too dry to be healthy for your plant. Underwatering is an especially grievous offense when it is combined with an overdose of nutrients.

If this has happened to your plants, it is at least a simple fix: just add more water. Start watering them more regularly, and they should start to bounce back quickly and relatively easily. Even if the soil mix is “hot” (which means that lots of nutrients have been added), your plant should have a good chance of adapting to it with an adequate supply of water.

Nutrient problems

Marijuana Seedling Nutrient-problems
Marijuana Seedling Nutrient-problems – Image Powered by growweedeasy.com

You will recognize nutrient problems in your seedlings if their leaves are yellow, crispy, spotted, or have other forms of discoloration. Your marijuana seedlings should be green at all times – it’s as simple as that. The nutrient problems might come from too many nutrients, too little nutrients, the wrong kind of nutrients, or something else.

If your plant exhibits symptoms like tip burn and dark leaves, it probably has a nutrient toxicity of some sort. After a while of an untreated nutrient toxicity, you will start to see other symptoms, such as yellow lines located on the seedling’s lower leaves.

If your plant has a nutrient deficiency, then its leaves will probably look pale or yellowing, and you might also see signs of other leaf discoloration. A nitrogen deficiency is almost always at fault, and this will make the leaves include brown with the yellow, and will go soft and will fold before they become crispy and drop off the plant. Don’t be deceived if the yellowing leaves are actually located at the top (newer growth only) – if this is the case, then it is unlikely that nitrogen is the nutrient at fault. A nitrogen deficiency generally affects the oldest leaves at the bottom of the plant before it reaches the other leaves elsewhere.

Problems with bugs can resemble nutrient deficiencies at first, so be careful to identify the symptoms correctly.

Your seedling’s nutrient problems might come from a “hot” potting mix, meaning it has lots of nutrients in it. This can simply be solved with adequate watering and waiting until the seedling has “grown out of it.”

If your soil is slow release soil, such as Miracle-Gro soil, it can cause nutrient burn and will eventually damage your final yield and bud development in the flowering phase. Don’t ever use a slow release soil.

Download my free marijuana grow guide at this link for more on nutrient burn

Seedlings don’t need many nutrients, so don’t overload them with them. As long as you have started with a high-quality potting mix, you shouldn’t add more nutrients until at least after the first few weeks of growth.

A nutrient toxicity can develop very quickly (within one night!) if you dump your plants with lots of nutrients all at the same time. When starting to feed your seedling nutrients, you should always use just half of what is recommended on the provided nutrient schedule. Check how your seedlings are reacting to it, and then you can increase the dose from there.

If your seedlings have a nutrient deficiency, it is most likely that a nitrogen deficiency is to blame. A nutrient deficiency of any kind could come from using a soilless medium that doesn’t have any added hydro nutrients, which are necessary for a hydroponic growing system. Another cause in a soil-based growing system could be that the grower isn’t adding in nutrients when the plant has used up the soil. Nutrients in soil don’t just sit there forever; they are absorbed and used by the plant, meaning you will always need to add in some more as time goes on.

One of the most common causes of a nutrient deficiency is feeding your seedling or plant the wrong type of nutrients. You need to make sure the right type of mix and use the right mix during the correct stage of life. Use a vegetative formula for your plant’s beginning part of life, and a “bloom” formula for the flowering and budding stage.

Once the plant is fully grown you will need to start thinking about flowering and harvest time. Our free little Harvest Guide will help you determine the best moment to cut your plants. Download it here.

Another common nutrient problem with marijuana plants is a pH imbalance. Make sure to always maintain a balanced pH level, and you should be aware of the fact that the pH level will fluctuate. Improper watering (see above) will also cause a nutrient deficiency if left too long. Planting your seedlings in a container that is too small will lead to them becoming root bound, which will cause your seedlings to display symptoms of nutrient deficiencies. Problems with bugs can resemble nutrient deficiencies at first, so be careful to identify the symptoms correctly.

High temperatures

High temperatures marijuana
High temperatures marijuana – Image Powered by growweedeasy.com

If your plant is experiencing too high of a temperature, the leaves will start curling at the edges until they look like tacos or canoes. They will also wilt and start showing spots.

Make sure to keep a constant eye on the temperature of your grow room, or know the weather to see if you will need to install any special equipment to keep the air temperature of your plants down. Seedlings are happiest when the temperature is somewhere between 68 degrees and 77 degrees Fahrenheit. Make sure to use your own thermometer to double check this. You should also be sure not to position your grow room lights too close to your plants, so you can avoid burning on the closest parts of the plants.

Improper lighting

Improper lighting marijuana seedlings

Burnt leaves, crinkled leaves, tall seedlings that are falling over, and lots of stem spaces between nodes are all symptoms of too much or too little lighting. Plants that are too tall have experienced too little light while plants that look burnt or fried have had too much light.

Whether it’s too much or too little, improper lighting can cause some serious problems for your marijuana seedlings. Luckily, it’s usually an easy fix: just move the lamps closer to or further away from your plants. If you are growing your plants outdoors, try covering them up on extremely hot days, and make sure every bit of your plant is exposed to direct sunlight. If they are exhibiting signs of lighting problems, you can fix the problem early on by adjusting the lights, and this should be enough to get your seedling back on their “feet.”

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

Marijuana plant symptoms

Marijuana seedling symptoms

Leaf symptoms:
– Discoloration
– Yellowing
– Crispy texture
– Spotted
– Tip burn
– Burnt edges
– Pale leaves
– Death of leaves
– Slowed growth

Plant symptoms:
– Wilting
– Drooping
– Algae growth
– Improper growth
– Slowed growth
– Dark green
– Stunted growth
– Twisted growth
– Discolored new growth
– Other discoloration

In general, your seedlings are going to want a moist environment, warm temperatures, and some light. They aren’t going to want much for nutrients. As long as you follow these points, your seedlings should be perfectly happy and healthy.

Remember that plants with strong genetics have less change of getting sick and are less vulnerable for diseases, deficiency’s, pest and environmental stresses. So make sure to buy marijuana seeds from a trusted seed bank.

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]

61 Comments

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  1. By Christopher Stanborough

    ,25 Jul 2015
    Just placed my first order excitedly waiting thanks Rob..
  2. By mike

    ,31 Jul 2015
    I have bought your seeds and love em but 2 of my white widows are showing signs of a problem. Can I send you drop box address and you look at my video of my girls and advise me? Thanks […]Read More
  3. By Brian

    ,31 Jul 2015
    Seedlings have been an absolute nightmare for me, 99% failure, and the ones that grew (just a little luck I think). Very interesting, but sometimes overbearing for us amateur growers, the seedling symptoms seem to tick all of the above […]Read More
  4. By Kirk

    ,31 Jul 2015
    The northern lights seeds I got from you are all growing nicely. Thanks for replacing the widows that didn't germ. I do thank you for your great service. I received all my orders from you in 10 days. I am […]Read More
  5. By Kevin

    ,01 Aug 2015
    Hi there Robert, Greetings from way down under! I’m in Tasmania, Australia, my name is Kevin, and I downloaded your Grow Bible a couple weeks ago, it has been a great help. This is my first indoor grow, and only […]Read More
    1. By Jennifer ILGM

      ,03 Aug 2015
      Hi Kevin, Thank you for sharing and come back anytime!!
  6. By Brian B

    ,02 Aug 2015
    Hi Robert, We are first time growers and using Coco and perlite mix. The seeds have germinated and in the first stage of vegetation. We have a grow tent which we have set up with everything suggested including air conditioning. […]Read More
  7. By latewood

    ,05 Aug 2015
    Brian. You do not feed seedlings nutrients until they 4-5 true sets of alternating leaf sets. I( suggest you join our "Support forum" and start a topic using our "Support ticket" as a guide to the info we need to […]Read More
  8. By Nobuntu

    ,27 Aug 2015
    Awesome blog you have here but I was wondering if you knew of any user dssucsiion forums that cover the same topics talked about in this article? I'd really like to be a part of group where I can get […]Read More
    1. By Greg

      ,15 Sep 2016
      all growers. Ask anything and they will help you. Good friendly people.
  9. By Gabyzinho

    ,27 Aug 2015
    Excellent site you have here but I was curious about if you knew of any dcouissisn boards that cover the same topics talked about here? I'd really love to be a part of group where I can get advice from […]Read More
    1. By Jennifer ILGM

      ,31 Aug 2015
      Hi Gabyzinho, Join our support forum at http://support.ilovegrowingmarijuana.com/, there you will be in contact with fellow and expert growers. You can post pictures, get advice or give advice and join discussions.
  10. By Jay

    ,10 Nov 2015
    Received seeds quick, they all popped and all are female. Just like they supposed to be. Thanks so much for great service and very helpful forums.
    1. By latewood.ILGM

      ,12 Nov 2015
      Jay You are so welcome. Glad to see you Happy and Growing! Peace
  11. By elizabeth

    ,10 Nov 2015
    my seedlings from my own seeds, neighbor had male plant which got to a couple of my girls, but anyway my bottom leaves are turning yellow they are 6 weeks old and have about 4 to 5 levels of leaves […]Read More
    1. By latewood.ILGM

      ,12 Nov 2015
      elizabeth It is time to give your plants a light nutrient solution of 400 ppm. You need to make sure whatever you are growing in is PH proper. I suggest you join our support forum for broader advice and support.
  12. By Louise

    ,11 Nov 2015
    Hi Robert i need some advice and help please. Ive been fairly successful at out door growing in a much higher altitude and colder climate. We relocated to a lower, coastal climate that is quite a bit warmer and frost […]Read More
    1. By latewood.ILGM

      ,12 Nov 2015
      Louise We cannot tell you what is wrong. All we know is that you are growing outdoors. The amount of hours you get Sun at this time of year is going to induce flowering, because the days are getting shorter. […]Read More
  13. By driverman

    ,12 Nov 2015
    How do you prevent streching in deedlings?
    1. By latewood.ILGM

      ,12 Nov 2015
      driverman, More intense lighting is the key to stifling stretching plants.
  14. By Organic_Gangsta1

    ,22 Nov 2015
    Need help with Chem dog seedling on 1 and half week old and still on first fan leaves outdoor grow
  15. By Organic_Gangsta1

    ,23 Nov 2015
    Need help one half week old seedling looking healthy Chem dog out door grow but still on first set of fan leaves been growing for 15 years this never happened to me
  16. By Bill Barra

    ,23 Nov 2015
    Please help seedlings with five sets of leaves starting to turn pale between veins & wilting on tips of one plant PLEASE HELP!!! What do I need to do? Thank you billb.
  17. By latewood.ILGM

    ,24 Nov 2015
    Bill, The best way to help you is to have you join our support forum. You have to read some posts, and stay logged in for at least 20 minutes, You may also need to post 5 replies for security […]Read More
  18. By Louise

    ,29 Nov 2015
    I forgot to mention im from Australia, so we havn't reached the Summer Solstice yet, days are still getting longer, which is why my early heading is so queer and has never happened before. I thought initially last year it […]Read More
  19. By latewood.ILGM

    ,30 Nov 2015
    Louise, I am not sure I know what you mean by heading. Ok. Aussie. Reverse Spring to ours. You mention heading, and proclaim all environmental issues and PH, nutrients etc. are fine. I really do not know what to tell […]Read More
  20. By Jeanette

    ,29 Dec 2015
    Hi this is my first attempt growing. I think my seeds are doing ok but not really sure. Is there someway I can send a picture and can be told if they are doing good. Thank you for your help […]Read More
  21. By Zog Loncaric

    ,26 Feb 2016
    Is it best to give 8 hours darkness in a 24 hor cycle and why?tanks,Zog
  22. By latewood.ILGM

    ,26 Feb 2016
    Zog, It is highly recommended that you have 6-8 hours of complete uninterrupted darkness while in the Veg Cycle Photo period. Why? Plants need rest just like humans do. They transpire in the dark, and in general photosynthesis is better […]Read More
  23. By Franklin Souza

    ,29 Jun 2016
    Mahalo(thank you)for the seeds.....they arrived promptly. I now have my seeds and am ready to grow my own! Any advice on the growing season in Hawaii? When should I start my seedlings? 1st time grower! Mahalo again!
  24. By cory Simpson

    ,15 Sep 2016
    I'm having a problem with the seeds rooting. I've watched all kinds of videos and I'm not sure what is the best way to get the seeds to pop.what do you recommend?
    1. By Roy ILGM

      ,16 Sep 2016
      We usually apply these germination instructions. We recommend putting them in a glass of water for a few days, until they grow a little tail. This can take more than 24 hours in some cases. Make sure the temperature of […]Read More
  25. By kelvin

    ,29 Sep 2016
    How to kill bug and insect flying around your plant.
  26. By latewood.ILGM

    ,30 Sep 2016
    kelvin, I always start out with hanging yellow sticky traps. If that doesn't work, I suggest you join our support forum and we can help identifying the pest and can advise you as to how to control them. Happy growing […]Read More
  27. By Magnum

    ,20 Jan 2017
    ILGM is the best place to visit for information on growing and if you decide to order seeds this is the place to do so! I have never lost an order and EVERY seed i have ordered has grown to […]Read More
    1. By Roy ILGM

      ,23 Jan 2017
      Awesome! Good to hear Magnum!
  28. By Mark

    ,23 Feb 2017
    I have your autoflower blueberry at the seedling stage. One has just started the second set of leaves. The other looks like the second set started but they look dead. What may be the cause and is there any hope […]Read More
    1. By Roy ILGM

      ,24 Feb 2017
      Hi Mark, best hop onto the support forum and share all the details. Our experts there may be able to help out
  29. By Farhod Azarbaydjani

    ,04 Mar 2017
    Would love to buy some seeds. How? Where? I don't see any contact information.
  30. By Dean

    ,01 Mar 2018
    I got my seeds will start to germinate them shortly in Miracle grow starting soil in small containers, when they get 4 to 5 sets I will transfer to 8 gallon containers, what type of soil should I buy? I […]Read More
    1. By latewood_ILGM

      ,07 Mar 2018
      Dean, What type of soil to choose is entirely up to you. I suggest you find an organic soil made regionally close to you. You can build your own soil also. Perhaps if you join the ILGM forum, we can […]Read More
  31. By Zack

    ,10 Mar 2018
    Yesterday I left my 2 week old aks an when I came to check on them the next day one of my best looking plants is droopy an yellowing started from the tips headed to the center. But all the […]Read More
    1. By latewood_ILGM

      ,13 Mar 2018
      Zack, This could happen if you give the seedklings nutrients too early. I think you would be better off joining our support forum where we can advise you in a much broader and informed level. We need some more input […]Read More
  32. By Aaron O’Brien

    ,28 May 2018
    Would you recommend urinating in my nutrient solution water for my plants?
    1. By latewood_ILGM

      ,01 Jun 2018
      Aaron, NO! Urine must be processed and diluted before being used to amend plants.
  33. By Mary

    ,28 Jan 2019
    Is lighting the issue at two three weeks why are my plants so skinny and leafless
    1. By latewood_ILGM

      ,29 Jan 2019
      Mary, Lighting is very important to the growth of seedlings. you need a T5 lamp 1-2" above the sprouts and a small fan to move the stem and strengthen it, in order to keep them compact.It is hard to tell […]Read More
  34. By Connor

    ,03 Apr 2019
    Thank you for this! It has helped a lot!
  35. By WILLIAM

    ,24 Apr 2019
    Truly excellent customer service. results are good and I will change a few things for greater Yield. genetics are really good. Autos are small for the most part. Northern lights was the exception. It is twice as tall and is […]Read More
  36. By Dennis

    ,26 Jun 2019
    Sky walker seeds germiinated Successful. Started In a glass of water until I not a beginiging growth. Then Put them In small pot. Transferred to a Large container. Growing beautiflly.
  37. By Steve

    ,27 Jun 2019
    I grew last year with miracle grow and. Molasses to good results. Is anything wrong with using miracle grow?
  38. By ken

    ,27 Jun 2019
    I have had no problem with new seeds sprouting but just wont start good root development. maybe should not use miracle grow soil anymore but what is the best ever heard of cola coconut hull hair.
  39. By Matt

    ,27 Jun 2019
    Thank you Robert it just so happens I needed this article so bad it was the exact thing I'm dealing with and now I know the temp is too high and the little nutes are not to little so thanks
  40. By Noel

    ,27 Jun 2019
    Professor Bergman, hello my name is noel Gerena and 95% of what I know I have learned you. I appreciate your expertise and excellant simple explanations for complex processes, I have but a few suggestions as a total fan but […]Read More
  41. By Bruce

    ,27 Jun 2019
    I tried many times to get my grow bible and signed up over and over again. but to no avail. Help.
  42. By Dave

    ,29 Jun 2019
    Hi folks I’ve been growing for some years and have Some experiences and now want to exp som different strains but was curious about the var of seeds and wether they would require much different fertiliser mediums to grow,... i […]Read More
  43. By Ranay

    ,09 Jul 2019
    Good and helpful information! Thanks!
  44. By Ctaig

    ,17 Aug 2019
    Robert i have some white widow i just got from you and i have my first batch White widow wont germonate .. i put a seed right in soil and it came up!! Go figure.. I usually have gotten seeds […]Read More
  45. By david ambrose

    ,23 Aug 2019
    When growing outdoors...is growing in a glass/uV preventing greenhouse self-defeating.....?.......i have read that it takes uV sun rays to change CBD to THC.....is this correct ?

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