9 Common Mistakes Made By New Marijuana Growers

May 2, 2020

In any field of work or play, beginners tend to have a rough time of it. Before you have successfully traversed the learning curve, you will probably struggle a bit with just about anything. Growing marijuana has an especially steep learning curve, so newbies definitely will make some mistakes over and over again before they truly learn. The key is not to feel discouraged – that will hinder your learning.

In short, don’t be surprised when you realize that someone else (who has likely been growing marijuana for years and years) is having an easier time while you are struggling during your first year or two of growth. Don’t let this stop you from trying! People who never try something will never succeed at it, after all.

Luckily, you can use the past mistakes of other beginners to your advantage. There are many mistakes made by just about everyone when they first start out, so we have compiled a list that describes them, as well as how to avoid them. Do your homework and you may just get over the learning curve faster than you expected. Start by downloading my free grow bible.

Blabbing and bragging about growing marijuana

Blabbing and bragging about growing marijuana
Blabbing and bragging about growing marijuana – Image powered by Zenpype.com

The number one error of new marijuana growers is bragging to their friends about how they are going to try growing marijuana this season. Or some people don’t brag about it, but rather confide in close friends. In either case, you are putting yourself at risk. If your good friend confides in someone else, and the chain continues that way, a snitch could easily be somewhere down the line, and your crop will be destroyed — not to mention the fact that you could be in some serious trouble. Whatever you do, don’t blab.

Failing to prepare

Failing to prepare
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For many, growing marijuana sounds like an exciting new hobby to try. While this isn’t exactly false, the fact is that it is also a lot of work — and not just during the growing season. Expert marijuana growers are spending loads of time preparing beforehand. Even if they use an outdoor grow area, they still are planning for the summer in terms of how much water and nutrients to feed their plants, what seeds to buy, and how to prevent pest infestations.

Many new growers, on the other hand, jump into growing marijuana without ever doing enough of their homework beforehand. You should be well aware of what exactly your marijuana plants are going to need in terms of light, water, nutrients, CO2, and ways to prevent pests. You should know which obstacles might come your way, and how to cope with them if they do, or, at least, have the proper materials and resources available to you for reference. Something unexpected always comes about during a beginner’s first growing season. The best way to cope with it is to have already prepared beforehand.

Poor genetics marijuana seeds

Poor genetics marijuana seeds
Poor genetics marijuana seeds – Image powered by Growweedeasy.com

Many new growers are not willing to commit lots of money to buy extremely high-quality products for their plants. They would rather test the waters first and see how it goes before they decide to grow every year for the next decade while paying a pretty penny for it. Beginner growers either pay too little for their starting seeds and, therefore, get poor quality ones to begin with. Or they try to grow marijuana with a seed they found in the weed they bought. In either case, the results will surely be disappointing.

The key is to buy from a reputable source and to make sure that you are paying for high-quality seeds to accompany the other equipment you have bought for growing marijuana. If you start with poor genes, you are actually wasting your money. So start out with good seeds and strong genetics, and you will find yourself enjoying better results altogether.

Soils and fertilizers

Soils and fertilizers
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If you haven’t grown marijuana before, you probably don’t know too much about which fertilizer you should use to grow healthy plants. For many beginning growers, this means that they simply buy whatever they stumble upon at the store. They won’t bother doing detailed research about how much nitrogen, phosphorus, and potassium marijuana plants need at each stage of their lives. So, their store-bought fertilizer might not get them where they want to go.

The NPK value is displayed on fertilizer bags, so you should go into a store already knowing how much of each nutrient your plant will need during its current stage of growth. Unless your plants are in their flowering phase, they will need more nitrogen than other nutrients. Plants in their flowering phase are going to need more phosphorus.

The soil is also something commonly messed up by new growers. Many assume that the soil in the outdoor grow area that they have chosen is nutritious enough because it’s natural. The fact is, however, even natural soil could be far too acidic or alkaline, or does not have ample nutrients for your plants. Be sure to test it extensively for pH. See if it is sand or clay soil, and then make changes accordingly.

Testing and maintaining pH

Testing and maintaining pH
Testing and maintaining pH – Image powered by Herb.co

Many beginner growers underestimate the importance of maintaining a healthy, balanced pH level. In reality, pH is one of the most important and potentially detrimental aspects of a healthy growing environment. If the pH is not good, your plants will end up sickly and unproductive. Plants growing in soil with a bad pH could even die.

The pH determines how much of certain nutrients your marijuana plants’ roots are able to absorb. If the pH is at the right level, then your plants should be able to absorb and retain any nutrients they need at any time. Therefore, it is critical to test the pH level often. Buy a pH testing kit before you even begin growing. If you are growing in soil, the healthy pH range is between 6.0 and 7.0. If you’re growing in a hydroponic system, the healthy range is from 5.5 to 6.5.

Too many nutrients

Too many nutrients
Too many nutrients – Image powered by Magazine.grasscity.com

It is extremely common for new growers to give their plants far too many nutrients than what is necessary. They have the mindset that you can never have too much. That, unfortunately, is not true.

Part of the issue is that store-bought plant nutrients include a feeding schedule. New, naive growers try to follow that schedule, but it almost always instructs you to feed your plants far too high doses of nutrients. This can cause a nutrient burn, which will have a negative effect on your plants. Like with pruning, just try a little at a time.

Download my free marijuana grow guide at this link for more growing tips

A good rule of thumb is to feed your plants via the provided schedule, but divide it by four. In other words, just do a fourth of the recommended dosages. If you have been maintaining the pH level, and your plants start showing that they are nutrient deficient, then you can increase the dosages by small increments. Half strength should be more than enough.

Container growing

Container growing
Container growing – Image powered by Theloud100.wordpress.com

If you are growing your marijuana plants in containers or pots of some sort, you have to be very careful not to let your plants get rootbound. Rootbound means that the roots have grown all the way around the edges and bottom of the container because it is too small. Because the roots generally grow much faster than the rest of the plant in your marijuana’s young stages of life, it’s easy to forget about the risk of being rootbound. Rootbound plants can quickly die, so it’s important to move them to a larger container as soon as possible — but do so carefully.

Overwatering marijuana plants

Overwatering marijuana plants
Overwatering marijuana plants – Image powered by Growweedeasy.com

The other aspect to avoid is overwatering your plants, which can actually happen if your plants are growing in containers that are too large for them. Beginner growers tend to water a container until all the soil is damp, which usually ends up being too much water for their little roots to absorb. The water will sit in the pot, depriving your plants’ roots of valuable oxygen, and this can lead to the symptoms of overwatering.

Overwatering can also occur when a new grower is watering their plants too often. You will notice the symptoms of overwatering when the plants droop, but luckily it’s fairly easy to fix, and it usually doesn’t kill off the plants… although it certainly is capable of doing that, when left unchecked.

The key is always to press your finger into the top inch of your soil to make sure that it is dry. If it isn’t, don’t water yet. If it is dry, however, it is the perfect time to quench your plants’ thirst. Don’t neglect to test it this way every time, or you could end up with the serious symptoms of overwatering.


Over-pruning – Image powered by Growweedeasy.com

Some overzealous beginners get a little bit creative with pruning. When it comes to pruning, remember that less is more. Pruning can increase growth, but if you do too much of it, then it almost certainly will hinder the growth instead. Just try one or two methods conservatively, and observe its effect on your plants. This will help you learn what to do next time without completely destroying your crop.


What do you need to start growing marijuana?

You will need a light source (sunlight or artificial lighting), a supply of fresh air (plants feed on carbon dioxide) and a source of food (fertilizers or a large soil).

What is the best soil for growing marijuana?

While shopping for the soil, the options available at your local garden store might overwhelm you. Consider the type of soil as the fundamental structure of your soil. Look at nutrients, micro-organisms and other changes from there that improve your soil.

What are the best nutrients for growing marijuana?

Cultivating a diverse and healthy population of soil microbes and mycorrhizae in the soil is key to successful organic growing. The best (and cheapest) method of inoculating your soil is through actively aerated compost tea (AACT), something you can make with just a few cheap items.

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


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]


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  1. By chris ,24 Feb 2016
    I'm growing to plants and they seem to be doing good the only problem is my leaves are leaning a lil down and a few leaves were turning yellow and the pH levels are fine maybe I'm not putting enough […]Read More
    1. By Craig ,23 Feb 2019
      Don't go with to many nutrients if you use to many they can get locked into your plant and even flushing won't help, the joint will keep going out and you will have shitty black ash
    2. By Vickie ,18 Nov 2020
      Hi I'm a newbie period my Lucy's get started. They grow a nice tail and I put them in the dirt covering without an eighth of an inch of soil and then I water the little grow cup completely 5 […]Read More
  2. By latewood.ILGM ,24 Feb 2016
    Generally, if you have droopy leaves; It is due to either over watering, or under watering. Yellowing leaves tend to point us to over watering; Especially if PH is correct. 5.8 for hydro; 6.5 for soil.
  3. By Jacob Melvin ,28 Feb 2016
    hello: I ordered my product on 2/4/16 and have yet to receive the package. Getting a bit nervous here....
    1. By Jennifer ILGM ,01 Mar 2016
      Hey Jacob, please contact support, they will look in to it for you.
    2. By Abbott Fletcher ,16 Mar 2016
      My order arrived in 12 days, exactly as promised, FWIW.
      1. By david geiger ,28 Jan 2018
        Mine came today via Royal Mail, honey they ain't cheap!
      2. By Tammy ,22 Jan 2019
        I have never had an issue with purchasing from them. I have always received my products and they came out great. Cant wait for this years growing season.
    3. By MP ,26 Jan 2018
      Don't be dude, they are the real deal. I was thinking the same but 2 otders later I am totally sold on these groovers 🖒
  4. By Leroy ,03 Mar 2016
    Great read..lots of good info for beginners.
  5. By Jay ,03 Mar 2016
    I am a nube my question is can I use a combination of different types of light sources such as flouresant and led ?
    1. By bryce ,03 Mar 2016
      Yes........you can use different light type and sources. My self I use a 1000 watt metal halide as well as a 1000 watt HPS during the entire growing cycle. I keep moving the plants around in the room so they […]Read More
    2. By latewood.ILGM ,07 Mar 2016
      Jay, Of course you can. Many growers do this and in every combination of lamps you can think of. If you join our support forum; You will find many growers willing to help you and will get many ideas in […]Read More
    3. By Steve ,09 Mar 2016
      Yes of course you can. Everyone has their own opinions mine is choose MH or HPS once plants are out of seedling stage they help with the cold weather and you can't beat the results but my mate will use […]Read More
  6. By Jean ,03 Mar 2016
    I grew my first two plants late last year, indoors. I used the square foot gardening mix (1/3 peat moss, 1/3 vermiculite, 1/3 compost) and got great results. Started the seed in that mix, then transferred them to 4 gallon […]Read More
  7. By Lucky ,04 Mar 2016
    To much nitrogen in flowering phase cause small buds and chemical taste...
    1. By kel ,06 May 2018
      What happen when you dry your plant at 72 degree and the hum is at 30%? Can you still cure this.
  8. By Lucky ,04 Mar 2016
    one of the best source information for mj growing...Thanks Robert!!!
  9. By Mary Lou S. ,13 Mar 2016
    Gosh, I wish I had one person to communicate with to try to get my seeds. I've been waiting since Dec. 15th. I paid $25 for shipping. I hope I get my feminized seeds before the AZ season is over […]Read More
    1. By Jennifer ILGM ,14 Mar 2016
      Hi Mary, As i can see in the system your order was shipped and it should arrive soon. If you have any questions contact support.
    2. By MP ,26 Jan 2018
      Don't be dude, they are the real deal. I was thinking the same but 2 otders later I am totally sold on these groovers 🖒
  10. By Nine Common Mistakes Made By New Cannabis Growers (The Joint Blog) ,21 Mar 2016
    […] By Robert Bergman, ILoveGrowingMarijuana.com […]
  11. By Al ,28 Mar 2016
    First time grower .......My plants seem to be getting tall but not enough leaves .....I have used different types of light .....I am now using 4 ft grow lights .......How far should i keep the lights away from the plants […]Read More
    1. By latewood.ILGM ,30 Mar 2016
      Al, Your plant is tall and has little foliage due to the use of inadequate lighting, most likely. 4ft fluorescent lamps are adequate for vegging small plants but will not provide enough light for optimum growth. Therefore you must temper […]Read More
      1. By Mark ,05 Nov 2016
        I have been growing since 1975. Always started with the 4 ft. flourescents just for 3 weeks of vegetative growth. Keep them close as Robert suggests. You will need to change over to MH or HPS to achieve flowering on […]Read More
  12. By mohammad ,28 Mar 2016
    hi thank you very much for information , so i wanna know when to start fertilize?
    1. By Bill A Moon ,04 May 2018
      I'm growing for my first time indoor with tent.. Was told to trim big leaves off , to help nutrients to other parts of plants. But I'm afraid, I'm doing to much. Seen videos , where they just let them […]Read More
      1. By latewood_ILGM ,09 May 2018
        Bill A Moon, go to: support.ilovegrowingmarijuana.com in order to get this level of support. tag me @latewood when you post your grow pictures. I do not advise trimming or pruning leaves until the plant os more mature. Also; Removing the […]Read More
  13. By latewood.ILGM ,30 Mar 2016
    mohammad, You do not apply fertilizer until you can see that the plant has 4-5 true sets of leaves establishing that there are enough roots to take up minerals. Too much fertilizer can burn young plants; So, do not over […]Read More
  14. By Catherine ,03 Nov 2016
    Hello Robert, I found out the hard way about nutrients. I made it 1/2 strength and after about the third watering I noticed yellowish color to the center of one of the shoots. Since finding that I have stopped using […]Read More
    1. By Cedric ,03 Nov 2016
      I dont know if you were doing this but checking the ph in your water after mixing the nutrients helps. I also had a duh moment. After reading a few articles. Sure enough i was watering my plants with 4.0 […]Read More
    2. By Roy ILGM ,04 Nov 2016
      Glad to hear you were on time Catherine!
  15. By Harley ,03 Nov 2016
    I ordered some seeds recently. They arrived within two weeks [I live in Canada], in discreet packaging. NO complaints whatsoever!!!!
    1. By Roy ILGM ,04 Nov 2016
      Thanks Harley, good to hear all was well!
  16. By Cedric ,03 Nov 2016
    I have ordered twice from here. Both orders came. Second was a little longer. But still within then25 business days. I did have a messuo moment and i think i transplanted on seedling too early. It started dying on me. […]Read More
  17. By Jeremy Marcoux ,03 Nov 2016
    Seeds came quick and stealthy. Only 12 days, had no idea what I was even opening. All germinated in a few days. Very pleased so far. Would highly recommend .
  18. By Josh ,04 Nov 2016
    I have been growing for 14yrs and I'm still learning about growing. If you follow Robert and his great information in his growing bible then you shouldn't have any problems with your plants. I have also purchased seeds from Robert […]Read More
  19. By Mark ,05 Nov 2016
    Question-when transplanting root bound plants do you spread out the mass of roots or just leave them clustered together?
  20. By latewood.ILGM ,07 Nov 2016
    Mark, This question could start a big debate. Most growers want to transplant and stress the plant as little as possible. Others claim that slightly breaking the roots will cuase new vigorous growth. I tend to take the less stress […]Read More
  21. By doris Grierson ,08 Nov 2016
    my seeds are staying in the fridge in some rice and sealed hope they sprout when can you plant them in spring april ? doris
    1. By latewood.ILGM ,09 Nov 2016
      doris Grierson, I cannot truly answer you without knowing what region you live in. I can only assume you mean to plant outside. You can plant when Tomato's can be planted in your area. If you do not know when […]Read More
  22. By Christi ,21 Nov 2016
    I'm in flowering stage in DWC system all was going good then about 2 or 3 weeks into budding I started noticing the leaves turning yellow one one side of the plant. In fact the entire one side I can't […]Read More
    1. By latewood.ILGM ,22 Nov 2016
      Chrsiti, It is really hard to diagnose a severe issue like the one you are experiencing without more information on what and how, etc...if you know what I mean. ;) We have a "Support Ticket" at the ILGM support forum, […]Read More
  23. By latewood.ILGM ,22 Nov 2016
    Christi, You need to join our support forum. There, you can post pictures for members to view and give you solid advice. We have a great community. Hope to see you there! Just @latewood once you join and I will […]Read More
  24. By michael ,05 Dec 2016
    first timer having trouble finding the light to grow is there a sourse or web to go to.,
    1. By Roy ILGM ,06 Dec 2016
      Hi Michael, Amazon and Dealzer are fine places to get your lighting. You can ask around on our forum what kinds you need for your specific situation.
    2. By latewood.ILGM ,06 Dec 2016
      Hey MIchael, I also agree that joining our forum is a great idea for a new grower. We can help you make sure that you get the right equipment from the start. :)
  25. By Jim ,06 Dec 2016
    Just harvested 1st crop two white widow plants from seeds purchases @ ILGM quality seems poor.plant and buds looked really nice but taste and potrentcy not to good anyone have a clue as to what could have gone wrong followed […]Read More
    1. By latewood.ILGM ,06 Dec 2016
      Jim, We have many very happy growers who have successfully harvested our WW plants. There is no way I can just guess at what you may have done wrong during this grow. Evidently something went wrong. We want to help […]Read More
  26. By Rob ,28 Jan 2018
    Yup in the same boat as a few others here ordered my seeds mid 2017 & still recieved nothing after contacting ILGM support & getting the run around& no refund, they said they would do a refund or send another […]Read More
  27. By Daniel Olsen ,29 Jan 2018
    Hello fellow green thumbs. I ordered some seeds in November & they turned up in descret packaging within 2-3 weeks. (I'm in New Zealand) I'm now waiting on my second order. Not all my seeds have "cracked" open but do […]Read More
  28. By Anahida ,03 Feb 2018
    I have ordered seeds from Robert twice so far and both times they have arrived quickly and have all germinated— every single time. Thank you! (and hope this continues.)
  29. By Anahida ,03 Feb 2018
    p.s. also appreciate the website and all the info. I haven't used the forum yet, but I will.
    1. By latewood_ILGM ,07 May 2018
      Well then, We will see you at the forum. Happy growing.
  30. By MR. SMITH ,01 May 2018
    1. By latewood_ILGM ,07 May 2018
      NR. SMITH, We are sad to hear about your legal issues. Hope all works out in the fututre, Peace
  31. By Bob ,13 Jan 2019
    Thanks for the hints. I realized last year growing in my garden that the plants were struggling. Looking back, I can check several thingson your list as my boo-boos!
  32. By chuck ,10 Apr 2019
    Robert I have been doinging this sience I was 14 I started behind the barn and it had a mixture of cow shit and horse shit and the 100 plants istarted wiyh all came up whitch schocked me and I […]Read More
  33. By Ted ,10 Apr 2019
    Been growing outdoors for a few years now. I've tried using commercial nutrients and found my plants did better with just compost. This year I'm doing lSD. Does anyone have any advice or Tips?
  34. By Shelly ,10 Apr 2019
    I’m Not sure how to post in the forum correctly. But ive learned lots of information and feel that my plants are beautiful. Ive read so much of your information snd appreciate everything i teaf from you guys. Thank you
  35. By Elizabeth ,11 Apr 2019
    Thank you it was kind of you to provide this truly valuable information. I learned two things I did not know
  36. By Michael valenti ,11 Apr 2019
    Ordered my beans on April4 and got them April 8 I am shocked. In the 5 years of growing I have never got beans so quick. I am in Awe. Ilgm has my attention. If my Bruce banner goes well […]Read More
  37. By dennis ,11 Apr 2019
    my 2nd year. received seeds in 3 days. better than expected crop last year. can't wait to grow the "berry kush" this summer. very happy with my purchase..
  38. By steve ,12 Apr 2019
    gotta admit I was a little skeptical but after about a week they came through. they will be getting my business again
  39. By Dewaine ,12 Apr 2019
    I downloaded the grow bible and am very glad I did also reading the e-mails have helped me very much thank you!
    1. By Rusty ,04 Apr 2020
      My plants came up about a week ago. The stems are about 4inches tall but the leaves are still very Small. Color is good just vert small. Can you help?
  40. By Jeff ,12 Apr 2019
    I will be harvesting my harvesting my first plants from these guys Super Sour Diesel. The plants are Amazingly beautiful, nice and sticky with zero health problems! Excellent Genetics as promised this was my first purchase from ILGM and very […]Read More
  41. By Marc ,06 May 2019
    Leaves Have Lost serated edges. Seeds came from medical. Was agood indica.rounded leaves come out curly then straiten.any one Seen this. Are plants ant good? Also very hairy at early age.
  42. By Grant ,10 May 2019
    I'm growing Green crack, probably half way through flowering Stage, I'm now Finding a white powdery substance on some of the Leaves?
    1. By Stacy ILGM ,16 May 2019
      Hey grant, Sounds like powdery mildew! Please check out this article to learn how to get rid of it: https://www.ilovegrowingmarijuana.com/powdery-mildew/ Stacy
  43. By Fred ,24 Aug 2019
    My plants are Getting a few leaves with brown tips on them! I have been using Earth Grow fertilizer in the flowering stage. I have been 2 days EGF and 1 day just water. Should i just skip the EGF […]Read More
  44. By James ,29 Aug 2019
    How about temperatures in a grow room?
  45. By jimmyjimjam ,09 Nov 2019
    very good advice and well put together. im sure you have saved so many crops
  46. By Mrgrngene ,01 Dec 2019
    As a joke I germinated a baggie with 30 seeds that I found in a box in my garage. I figured 4 or 5 would pop, nope 29 little white sprouts, so I threw them into 2 24inch X 6 […]Read More
  47. By Cody ,12 Dec 2019
    This is very helpful information. Thank you
  48. By Reese ,11 Apr 2020
    I’m really new to this growing thing; I’ve never grown REGULAR plants...let alone, gas🙃 I have a 2 part question: how can you tell if your plant is dead (in beginning stages)? #2 of the plant stem is skinny & […]Read More
  49. By Donald ,22 Apr 2020
    Awesome advice thanks so much.
  50. By James ,30 May 2020
    Can I grow Bergmans gold leaf and purple haze next to each other or do they grow at varying rates and different heights which will make it difficult to adjust lights?
  51. By Joe ,16 Jun 2020
    I’m growing outdoors in containers. The soil will get dry in the top inch but a moisture meter shows me it’s wet down deep. Water or not?
  52. By Gail ,18 Aug 2020
    Can anyone tell me what size pots are good for autoflower seeds? I just saw that autoflower seeds don't like being repotted. After sprouting, what size pot? Thank you.
  53. By Angela ,09 Nov 2020
    Hi all newbie here!! can i grow without lights if my plants are under a sky light in fl?
  54. By Robert ,23 Jan 2021
    I keep trying to download the guide. Is it available in the states? Download doesn't initiate?
    1. By Stacy ILGM ,25 Jan 2021
      Hey Robert, Sorry to hear you have trouble downloading the guide! Please get in contact with [email protected] so we can help you out. Stacy ILGM
  55. By Bonnie ,24 Feb 2021
    what is the ideal temp range for starting seeds
  56. By Bonnie ,24 Feb 2021
    Not able to download the grow guude
  57. By William Ritchie ,14 Mar 2021
    I have a 5x5 grow tent and I haven't setup my air system yet. My seedlings are around 2" tall. I'm having a hard time getting the humidity to stay up.
  58. By Peggy ,13 Apr 2021
    The kush seeds i got from u are about 5inches high.ph is 6.5 not sure if i need to give them anything else what u think.suggestions please.

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