Increase Your Marijuana Yield

For every marijuana grower, achieving a high final yield is the ultimate goal. In an ideal world, this yield will be high despite less effort, time, and money being used.

There are a number of factors that can negatively affect your yield, so as a grower you need to always be aware and ready to combat these things to ensure a great yield.

What are the main things that can affect your yield? They are light intensity, pruning or training, nutrients, climate issues, and the harvest time. All five of these factors can lead to successful yields, but if they are not handled correctly, then they also have the potential to devastate your marijuana crop. You, therefore, need to be well informed and ready for any unexpected hurdles that might come your way. For example it’s very important for your plants to get the right amount of nutrients, so they can grow strong and healthy. An excellent product such as Marijuana Booster, will give your plant plenty and a variety of nutrients it needs and this can substantially make a difference in your yield.

More than anything, the genetics of your marijuana plant are going to have the greatest effect on the final yield. Make sure you choose a strain with a high potency and yield to begin with so you ensure that you can maximize your crop to an amazing extent.

Increasing light intensity

Increase light intensity in cannabis grow room

You will know your plants are having an issue with the intensity of the light by the way they are growing. For instance, if your plants are in their vegetative phase and are not receiving a high enough intensity of light, they will “stretch” upwards toward the source of light. This can lead to large spaces on the stem between nodes and leaves, or perhaps even growing tall enough to fall over.

Tall, lanky plants are not the type of plants that are going to get you a high yield – bushier plants will. Once these stretched out plants have reached their flower phase, it will be difficult to get them an adequate amount of light to increase their bud growth. To keep it simple, more light intensity leads to more (and bigger) buds. It’s, therefore, easy to understand why it’s such an important factor for your marijuana garden.

Light is by far the most important factor that can affect any marijuana plant. It is absolutely essential for the flowering phase of your marijuana plants, although many new growers don’t fully appreciate how much increasing the light intensity during that final stage is going to help their end yield. The process photosynthesis is fed by intense sunlight, which creates sugar, which is used for the flower growth of your marijuana plants. Uninterrupted darkness is equally important since this is the time that the plant can produce and let off the hormone florigen – if it doesn’t do this, it will not flower.

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

If your plant is experiencing a problem due to the improper intensity of the light, there are several methods you have at your disposal to combat the problem. Generally, more intense light leads to bigger and fatter buds. This, of course, means a greater yield – and greater success for you as the grower. It’s especially important to have high amounts of light intensity during the flowering phase since this is when your plants are going to grow their buds as much as possible. This is the easiest to achieve if all of your plants are the same height, with lots of colas close together. This is more or less impossible to achieve after your plants have already entered their flowering stage, so if they have grown unevenly then you will just need to work your hardest to make them receive intense light nonetheless. The tricky part about increasing the intensity of the light in your grow room is to not simultaneously increase the temperature of the room, as the plants need to remain cool during their flowering phase.

One simple way of increasing the intensity of light in your grow room is to move the light so it is positioned closer to the plant. This has to be within reason, of course, so as not to burn your plant’s tips. Remember: the best way to increase the size and potency of all the buds is to have each one exposed to direct, intense light.

In general, there is a low chance of you giving your plants too much light. Marijuana plants use up lots of light in the wild, so to surpass the point of too much would be surprising. As long as the light isn’t too close to your plants, you won’t have a problem with light levels being too high.

Although it might not seem like it is directly related to light, CO2 is another important factor that comes into play. CO2 enables your plants to take in more light than usual. Unless you are reaching the point of the light being too much for your plants, however, adding extra CO2 into the grow room is most likely a waste of time. If you are reaching this point, CO2 will be extremely beneficial to your plant’s end yield.

If you are planning on adding CO2 to your grow room, make sure you seal off the area completely so you can pump in extremely high amounts of CO2. This density of CO2 is dangerous for humans, so don’t walk into the room with the excess CO2 without taking proper precautions first.

Increasing yield by pruning

pruned cannabis branches

If your plants are receiving uneven amounts of light, meaning the tops of your plants (which receive the most direct sunlight) are growing more rapidly than the bottom sections of your plants, you may want to look into pruning and/or training your plants.

This factor goes hand in hand with light intensity since it will have a direct effect on the coverage and distribution of the light. Training and pruning allow your plants to become bigger and wider, and it is free and relatively simple to achieve. You can either top your plants (which utilizes the method of taking off the tops of your plants) or use Low-Stress Training or LST. Many growers prefer LST since it keeps the stress levels of your plants to a minimum (as the name suggests). LST’s idea is to coax your plants into growing flat and wide rather than tall and thin. It uses bending to achieve this goal.

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

If you are planning on using LST, you should start when the plant is still quite young. The ideal shape of a plant that has undergone LST is easiest to accomplish if you start from a young age. Instead of bending and tying your plant, you can also use a screen or netting to guide your plants’ growth to being more flat and wide. This method is referred to as Screen of Green.

If you want to train your plant a little bit differently, you should look into the method of Supercropping. This can be used on its own or to accompany another training technique. It is a way to force plants to bend when they don’t want to bend.

As far as actual pruning goes, the most popular method for marijuana growers is called Topping. Another popular method is FIMing the plant. Both methods include removing growth from the end of the main cola. If you do this at a young enough age, the result will be that the plant will stop focusing all its energy on this one cola. Instead, it will focus on the other colas that are full of buds instead. This ultimately leads to a higher yield.

Using the best nutrients

Use the best nutrients- cannabis nutrient burn

If your plants have sudden leaf discoloration, curling of the leaves, death of the leaves or other strange symptoms, the cause could easily be from too little (or too much) of one nutrient. There is the common identifiable problem called “nutrient burn” that shows your plants are receiving too many nutrients. Just like people shouldn’t fill their plate with multi-vitamin pills, you shouldn’t bomb your plants with nutrients. Too many nutrients make both humans and plants sick.

Your plants’ leaves are always the first place to show nutrient problems. Therefore, if the leaves of your plant all look similar and bright green, you can rest assured that there is no problem with your plant.

Contrary to what some new growers might assume, adding more nutrients will not automatically make your plant more well-nourished. You need to know exactly how much of each nutrient your plant is going to need, and during which phase. Sound complicated? That’s because it is.

Lots of growers have developed the bad habit of giving their plants too many nutrients. Another common mistake is when growers who haven’t fully educated themselves mix lots of nutrients together before adding it to their watering solution, without really knowing why or what they are feeding their plants.

There is a tendency to add too many nutrients.  Too many nutrients lead to poor plant health (therefore doing more harm than good).  You need to make sure you don’t let this happen.

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

Nutrient deficiencies are also detrimental to the health of your plants, so you need to find the balance between the two extremes. It is actually generally the safer option to err on the side of too little nutrients. If you use bottled nutrients, we recommend using only half of the suggested amount of nutrients. Simply do not raise nutrient levels unless you are noticing specific changes in your plant (i.e. leaves turning yellow at the base). You can also do it when you realize one particular plant uses a lot more nutrients than its neighbors. You will be surprised by how different the ideal amounts of nutrients are from plant to plant.

In general, it’s better to have fewer nutrients during your plant’s final 2-4 weeks before the harvest. If you see leaves dropping during this time, do not automatically assume it is a nutrient deficiency and start adding more nutrients. This will actually slow down your plant’s bud development, therefore resulting in a lower yield. Fewer nutrients during this time will also allow your buds to get rid of any residual “nutrient taste” that sometimes comes with plants that have been receiving too many nutrients. Don’t be afraid to allow some of the leaves to yellow, die, and drop off – it allows your plant to focus its valuable energy on high-quality bud growth instead.

The best way to avoid nutrient problems altogether in soil-based mediums is to form your own compost to make super soil. It can be totally organic and will give your plant every nutrient it needs throughout its entire life. You won’t need to worry about deficiencies and toxicities and can instead use your time and energy elsewhere.

Another option is like we mentioned before the Marijuana Booster. A great product composed of the exact right mix of nutrients to help the plant thrive and double your yield.

Create the perfect climate

Create the perfect climate for your cannabis plant

If your plant (or one particular spot on the plant) begins turning brown and wilting, you can be relatively certain that the excess heat is to blame. Excess or sudden cold will also lead to slowed growth and other negative consequences, so make sure to avoid this at all costs.

You need to maintain a steady, healthy climate for your plants to produce their maximum yield. A too high or too low temperature will result in a poor yield, as will improper levels of humidity. Make sure to always keep the temperature of your grow room within a certain, consistent range to keep your plants from slowing growth or having other negative side effects. If you keep the temperature and humidity level at the right spot, the final harvest will be rewarding. Even the smell and potency of the buds will be improved, so don’t forget about this crucial factor when it comes to maximizing your yield.

Harvest at the right time

Harvest cannabis at the right time

You will know you have chosen the wrong time to harvest if your buds aren’t fully ripe, or if they’re unusually small. Chances are, you cut your potential by about 25% by harvesting too early. If you wait too long, however, you will also lose some potency and smell.

There is a small window of time that is ideal for harvesting the buds of your marijuana plants. This window of time is between two and three weeks long. You need to ensure that you are waiting long enough to allow the buds to ripen completely. The final two or three weeks before the harvest can make a world of difference – buds can grow up to 25% more during this time! This is why it’s very important not to harvest earlier than the optimum window.

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

If you are trying to get a specific high from your buds, you can alter the harvesting schedule a bit. Buds harvested earlier generally have a buzzy high, best for smoking during the day. Later harvests lead to a high that is more relaxed couchlock feeling. Decide when you will harvest based on your personal preferences.

Marijuana plant symptoms

cannabis symptoms- heath burnt leaves

Leaf symptoms:

– Leaves curling upward
– Leaves curling downward
– Base leaves yellowing
– Heat-burnt leaves
– Spotting of leaves
– Yellowing or browning leaves
– Dropping and dying of leaves
– General discoloration (red, grey, brown, yellow)

Plant symptoms:
– Tall, “reaching” plants
– Lanky plants
– Nutrient burn
– Browning and wilting

While these five factors are the most common ones that can affect your marijuana plants’ end yield, they are by no means the only factors that have an effect. There are plenty of diseases or conditions that could affect your plants without you influencing it at all, so you need to be well-educated in terms of potential obstacles. If you do your homework and are proactive about your plant care, you will be finely rewarded. Check out our Symptom Checker for more plant symptoms.

Choosing the right genetics

Choose the right genetics- quality cannabis seeds

While there is nothing you can do after you have already purchased and planted your seeds to affect this, it is still worth mentioning that genetics play a key role in your plants’ final harvest. Your particular marijuana strain is going to affect the growth, size, and potency of your buds in the end.

The good news is that most strains that you are likely to buy these days have significantly higher yields and potencies than past strains. They are also generally easier to grow, and this is just getting better and better as time goes on.

Many beginner growers will pay the cheaper price for strains that are not high in quality. Although their intent was to save money, in the end they will actually get less value for what they paid because the end yield will be disappointing compared to a high-quality strain’s yield. This is why it is important to invest in high-quality genetics from the beginning.

There are different versions of high-quality strains, of course. Some strains achieve a higher yield, sure, but others have been bred specifically to achieve other useful characteristics like height and bushiness. Others were bred to have buds that are extremely potent or fragrant, meaning the yield itself might be lower, despite a higher quality bud.

Therefore, no matter what you do in regards to the other factors that affect your precious marijuana plants, you need to start things off right with a good strain. Do your research so you know exactly what that strain’s tendencies and expectations are. In the end, you will be glad you did.

If you want to skip further research and just start with quality seeds with a strong genetic background, then order your marijuana seeds in my seedshop. Shipping is stealthy and goes worldwide. As a beginner it is best to start with White Widow Feminised seeds.

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


Robert Bergman

Robert Bergman is an Amsterdam-based marijuana grow expert who has years of experience from small grows to massive operations. His passion for growing lead him to develop his own Gold Leaf strain. Now, Robert is dedicated to sharing his knowledge with the world.... [Read full bio]


marijuana grow bible
  • Grow With My Quick Start Guide
  • Discover Secrets To Big Yields
  • Avoid Common Grow Mistakes

    108 comments on “Increase Your Marijuana Yield”

    1. I really enjoy reading your information and advice. Con you tell me , what would be the highest wattage LED light to use safely in a 4×4 grow tent?

    2. I have one plant just want to grow taller and is about 4 ft in dia with no buds while my other two plants have flowers what with no flowers

    3. Hey Robert when did you start to grow what year .also do you ave any Thailand strains Thanks Robert

    4. Is it ok to bring outdoor plants inside at night into a dark room so they dont get ripped. Can co2 be used at night phase.

    5. There is an exception For a beginning grower to using white widow as a plant to start off with. It will not perform outdoors where you have a cool wet fall environment at all wasting your year. For example specifically Near or above 42.8 latitude in New York state. My email is all lower case letters which I’m not allowed to enter here by this site. If great indoor or tropical genetics don’t perform I will not bring the harvest home nor grow it indoors. I suspect breeding in more tropical Spain has absolutely ruined many good strains for my use. I e. Skunk #1 and Afgani #1 which suck now from those who claim to have it as I rip it out throw it on the ground pissed off ripped off.

    6. Great information once again,great to see there’s people out there that spend the time to help others and stop people making simple mistakes which Result in devastation of There crops,good on you ILGM

    7. Thank you for the info i’m changing it now to 18/6. i am learning a lot from you. Thank you! i’m just going to veg a couple more weeks then go to 12/12 to flower, get some bud and start new grow with my auto flowers. Thanks again latewood!

    8. mfirst time,

      Well you complainabout shortbushy plants, yet you top them and low stress training; Both of which are methods for keeping your plants short and bushy.

      Bushiness could be because there is more of an Indica pheno being shown by theplants.

      Last…”What am I doing wrong”? Answer. It is a bad idea and bad grow practice to use a 24/0 photo period. Never use longer than 18/6. Roots which are extremely important to yield grow the most vibrantly under 12/12-14/10 photo period. Most plants get vegged between 16/8-18/6 by expert growers. Do the math. 24/0…the least amount of root growth possible.

      Happy growing

    9. mfirst time,

      Since we are not set up for grow support here in the comment section of the blog; I suggest you join our support forum at and we will share all the knowledge you need to grow successfully. 🙂 I am 61. Peace

    10. Lee,

      Changing the photo period to 18/6 should not affect the plants. FFR: Never use 24/0 photo period. Start at 16/8-186, and then induce flowering when ready at 12/12.

      Happy growing

    11. i found the 1000wt burns them. even at 750wts it needed to be well away let alone if u crank it up to 1000 wts. its just that high of a out put of lite. best to use at 6oowts untill it is in flower and has stoped it big groth stage from turning. than crank it up to 750wts and u will see what i mean. at the very tops of crowns will look like their getting burnt even when u lift up high so u have to really get it up away from plants. but yeild. amazing even tho its a bit high up it penatraits deep so u dont have to worry about low airy buds. it still gets the lite to them. because they are just so bright. so keep a close eye on tips if u notice burning put it up higher untill only faint burning noticable. gives u big lite all over all over and deep down where its shaded.

    12. I am 60yrs old and i forget things. Things like these plants are super skunk and bubba kush. i can’t post pics though i wish i had a camera. I am trying LST on the super skunk, but it hard to bed as is so short. One of the bubba kush plants has been topped. The others have not, but they are very short and bushy. The light, a 1200 watt led, is on 24hrs. They all seem to be growing very slow. what am i doing wrong?

    13. I was just wanting some help. I’ll see if i can get it this time. My plants seem to be doing good, but are very bushy and short. My babies are growing very slow. Do i have a problem with nutes or lighting maybe? I am in need of some advise.

    14. Me again, I don’t want them to go into the flowering stage, that is what I am wondering. Lee

    15. I have had my plants on a 24 hour lighting schedule for a month now and they are doing great. My question is if I go back to the 18 on and 6 off, will they go into the flowering stage? They are growing like crazy and I was thinking of going back to 18 on and 6 off, unless that would hurt them then I will just stay on the 24 non stop lighting. Thanks for all the info you give out, very helpful. Lee

    16. Bama,

      You should be fine. Nature will do the job. Plants are big enough to flower and it is time. Perhaps you could join us in the forum and do a grow journal for your outdoor grow. Members are always willing to share ideas and experience with others.

    17. mfrst time,

      I have an idea…Go to the forum and start a topic where we are set up to help you and you can post pictures for us to form an intelligent answer around. See you there 🙂

    18. I’m a first time grower I’m growing outdoors my plants are about 3 to 4 ft tall and just a little over a month old the get about 12 hrs of good light is this good or not

    19. I have to say that I have purchased several lots of seeds from ILGM and because of the country where I live there was, on occasion, a problem with receiving them but as soon as IGLM was notified, I always received replacements (without purchasing more) and if these didn’t arrive, my money was reimbursed immediately. My dealings with IGLM indicate that this is a very honest and reputable company.

    20. Since many subscribers are spread worldwide it is not cost effective to order your nutrients and request that you inform us of the nutrient composition. Cost of transport makes this prohibitively expensive.for South Africa. Please help.

    21. Growing some super Gorilla Glue. Using three 1,000 watt LED lights. Using low stress training technique to obtain bushy plants. Lots of future colas developing.
      No hope without dope !

    22. Growing some super Gorilla Glue. Using three 1,000 watt LED lights. Using low stress training technique to obtain bushy plants. Lots of future colas developing.
      No hope without dope !

    23. If you are ordering seeds in the US – get a pre-paid card. The banks will not process orders internationally. Once you have a prepaid – you are good to go

    24. I love your forum ! I can’t get enough of your info. Definitely get the best info from you guys.I grow indoor with a 1200 watt led.My plants are short with lots of nodes. The only problem is they are growing very slowly. Its been a month and my super skunk is only 6″ tall with 6 nodes. any ideas?

    25. Absolutely not. The plants need to convert Co2 to O through natural photosynthesis. Pick up a Co2 generator or a natural organic bag Co2 maker and put with your plants. Be careful because to much Co2 is just as bad. I do the 3-4 method. I open my room doors for much of the light cycle (18 hrs veg 12 hours during flowering) to get a good room “flush”. I take out my bag during the last month of flowering and keep my doors shut for good control during final bud growth; keeping temp and humidity constant.

    26. I am hoping you found a way to salvage your plants. Hope you join the forum, so we can help you grow successfully from start to finish. 😀

    27. marti,

      Why did you pull your plants? Not much we can do to help you now. Perhaps if you re-pot them you might salvage some of the yield. Join us for information regarding your next attempt at growing your own. Peace

    28. I dont have indoor i have just 2 outdoor. But i have a problem w my buds . it started raining n i paniced . so i pulled them .but my problem is my buds aret hard .is there anyone who can advise me what is wrong

    29. Doin a gro of six under a 1 k led in a 2×4′ tent. They grow so stout I can’t ( don’t dare) try lst. Plan on letting the branches provide the extra colas. The gals r like bushes. Is this too good or have I fed to well. I’m so f’ing charged I don’t know if I can wait for the happy ending. The Ilgm product and staff r of the best and I personally recommend. I’m so tired of the old bunk and super delited with the current methods. If I had only one thing to tell you all is that upon starting the gro do this – use the paper towel method to germinate and the rapid rooters to start ur plant.

    30. Hey there SIRVIS,

      my first piece of advice is to get bigger lights.

      Now; A very strong warning. Be extremely careful attempting to split the stalk. Very very careful. It would be very easy to sustain a bad cut on your hands. It is not easy to cut through a stalk. Personally; I would not do that until I had my grow methods down, and had so much yield that one plant would not hurt my stash. Splitting the stalk may work, but it can go wrong also. Just be advised and informed.

      Happy growing, lw – I❤️GM

    31. This my first attempt at growing using 2 WW seeds indoors. My light source has been a LED shop light. Specs on the box say: 40 watts,4500 lumens, 5000K color temp, 86 CRI, 112 lumens /watt. (Lights of America)@ W**M**T. WallyWorld!!! don’t understand the jargon, but I got 2 beautiful girls using them around $30USD. gives off very little heat and a very bright and effective light. They are starting to bud, any advise? I have been going 24 hours using a CO2 generator I put together using yeast,sugar,H2O and a juice bottle. Pruned leaves smoke nice and mellow. helps remedy my insomnia. can’t wait to see how the buds will work. Going to try splitting the stalk in one plant to increase the potency.

    32. This may be a strange question to you. WHAT IS A COLA, I am assuming it isn,t a soft drink!!

    33. Matfucius say, “Worm crap with a little sulfur mixed into soil, makes for a good PH”. Also Matfucius say, “Water only with spring water”. That aside, these are the only people I’ll ever get seeds from. Outstanding genetics.

    34. SIRVIS,

      Worm castings are a great amendment for soil and soil-less grow mediums.

      If one wanted the best garden store plant food for Cannabis; It is generally recommended by growers to use; Tomato plant food. Happy growing.

      Perhaps you might join our support forum! Lots of shared information from knowledgeable growers. Peace

    35. I am growing earthworms to use the casting as an organic fertilizer. Will this be a sufficient nutrient. I was also told that rose food would positively affect my bud growth. Any input?

    36. I had a problem the first time I ordered but they made it right. I ordered 10 white widow seeds and got 10 free. I started 4 of them, all 4 germinated and grew. I am just now harvesting after 3.5 months with a yield of about 20 ounces. I am one very happy customer.

    37. I have seen newspaper column homemakers hints that advised using flat club soda to water house plants. So this is a valid CO2 question ♡

    38. No. CO2 is Absorbed by the leaves the plant breathe out oxygen and breathes in CO2 through the leaves the roots breathe in oxygen if you give CO2 to the roots You may do them harm or do your plant harm

    39. Elaine, I had the same question a bit ago. FIMming stands for “F**k, I Missed” – often heard when growers are attempting to Top a young plant and get an incomplete or inaccurate cut. It causes yet a different growth style from a completed Topping, since it takes only the growing tips of the new shoot, not the entire shoot. Hope that helps.

    40. […] cost you around $30,- but it will pay for itself after one harvest. Experienced marijuana grower yield up to 21 oz of marijuana  with one HPS 600-watt light. Of course all the other circumstances […]

    41. Yeah I absolutely love all the posts that you put up I get so much information from them it is just wonderful n very kind of you to share that information with all of us Growers thank you.
      I read all of your blogs and I have downloaded everything that you’ve had to offer and I’ve actually downloaded things twice by accident LOL. I have also bought seeds from you and was very impressed at the speed at which I got them and also the quality was wonderful

    42. I am just like you grew before but with all this new info available it’s as if we really couldn’t grow. I research a lot also and have spent a lot of time and money on books, but find myself always comming for more with Robert. Thanks

    43. I happen to enjoy making wine as well has growing medicinal marijuana. When making wine carbon dioxide is one of the byproducts of the yeast that is used to make alcohol. CO2 is heavier than oxygen so it falls down in my system. I use a grow tent with a tube at the top of the tent from the wine Brew. Very dark green leaves. Hopefully a great crop to follow. To make wine you get a six week window of carbon dioxide being produced. And wine goes well with medicinal marijuana at the end of the day. Cheers.

    44. […] in the screen allow the glands to drop through while the vegetable material stays on top. The yield is dependent on the quality of the material you started with. You can find suitable framed screens […]

    45. […] you maximize your plants’ growth, you maximize your yield and quality of weed. There is no better way for your plants to grow than to make sure that it is […]

    46. The best thing you can do is to join our free support forum. We have expert and fellow growers there that would love to help with anything grow related. You can post pictures, ask questions and share experiences.

    47. I had problems 30 deeds not one grew, I contacted them and received 30 more in a month. I only had 12 of the 30 start, not happy about that. But ordered 20 high dollar seeds to see if I get better results. I would like to see at least 5 white widow seeds to see why the wont grow.

      Thank You
      your support team was helpful

    48. I ordered 30 white widow seeds, out of 30 not one made it. I contacted support and they sent me 30 of a variety.
      only 12 of the 30 started, but I now have 12 very good looking plants. I ordered 20 super skunk seeds at a hefty P price. I am hopeful for better results. I have read the bible over and over and can not figure out why such bad results. I am relentless though and will get better. thank you all for your intell

    49. This is not true. I have honestly never heard of anyone that did not get seeds replaced after a propagation failure. In fact; We replace seeds even though it might be the growers fault.

    50. J-BO,

      All this is explained in our Free Grow Bible. A full grow from planting a seed can take as long as; 18-24 weeks. (2 weeks of seedling growth. 8 weeks of Vegetation. 8-12 weeks of Flowering, depending on strain.

      Some growers cut down Veg time to 2-4 weeks, but produce smaller plants.

      Perhaps you should read our Grow Bible, then join our support forum. 🙂

    51. Regardless of the number of plants the volume of the rez is whats most important. A weekly change will give you the most consistant results as the nute levels will be balanced better. You could stretch it out to two weeks or drain and replace the water and nutes after you have added 1/2 the volume of the rez with fresh water. To make that simple
      20 gallon rez filled with nutes and water
      Once you have had to add 10 gallons of water to keep the rez full its time to do a change.

      30 years growing and these are my thoughts
      Good growings!

    52. So sorry you feel like our service is dishonest, I checked the email history and I must say, this is not the entire story. If there are any order issues please contact our customer service.

    53. I had the same problem with germ.Customer service said the only way I will get reimbursed for them is to place another order an they will add extra……not such a great guarentee,I have to spend more money to get a product in which I’ve already paid for..I most likely won’t order again due to the dishonest customer service.

    54. Is there or can you make a timeline that gives a round about time for each stage of the growth period from seed to harvest? I have no idea what I’m looking for so a timeline would be great. Thanks

    55. Squishy,
      Well said, and I agree. ILGM is a great resource from seed to harvest. I avidly read every one of Robert’s email/newsletters.


    56. If you are asking if you can grow plants in an open room under quality and powerful grow lamps; The answer is Yes. As far as yield; That would be determined by your methods, systems, nutrients, and just how far you go, in order to grow Premium Cannabis.

      All animals love Cannabis. Rabbits, Dogs, Cats, Dear, etc…

      I suggest you join our Support Forum for an opportunity to experience a more diverse answer from growers all over the world.

    57. Hi guys :), my order for white widow auto,s are on the way here.
      i have limited space and need to know since auto’s dont require specific day/night lighting regiments, can i grow them in a normal room with proper lighting above them and still get the harvest as i would have in a special tent/grow room environment ??
      also please…all of my white widow fems are growing great with lots of branches, but the ones i planted in the field out back have no branches on any of the four plants. just a single cola at the top. i dont get it…any help with these questions would be gratefully appreciated.
      Thanks in advance, Vern

    58. My man Vern. You are entering into an area that will and has to be, an experiment. When you grow outside normal parameters, you take chances. That is what is so cool about Cannabis growing. You never know how well the plant will adapt to adverse environment, until you try it. Aspiring to grow high quality Medical Marijuana is not for the timid…LOL Just kidding. Happy Growing! Peace

    59. Just thought i might add that my first two are almost ready to harvest and look great !
      i am using the deep water hydroponics which i also used twenty four lights from 800 watt CFL bulbs and couldn’t be happier. also using two 300 watt full spectrum LED light on my new grow and the are growing super fast and huge wide and tall also twenty four lighting. hearing what you are saying, i will switch to seventeen on and three off and see how it goes. thanks for the advice.
      still wondering about vegging outside the tent with the eight hundred watt CFL lights until i harvest the ones in the tent ?
      Thanks in advance for your input, Vern

    60. Peter newbie,

      One thing I can tell you. It is best to use proven and simple methods and hardware when 1st starting to grow. I have not used this lamp, I use digital switchable ballasts for vegetative, and flowering. I use a T5 set up for seedlings and early vegetative efforts. Hope this helps. 🙂

    61. Vern,

      Great testimonial. Thanks form all of us at ILGM. I too believe that the genetics offered @ ILGM are of superior high quality.

      I have to advise you on photo periods. Using 24/0 photo period is not a good idea; Especially for “Feminized seeds”. Using longer photo periods in early vegetative period does not allow for proper root development, and also can lead to hermaphroditic results. In order to better guarantee proper feminized results; One must use shorter vegetative times. 18/5 maximum, but 16/8 is even better. Science and test grow data prove this. Happy Growing. 🙂

    62. Just a question on lighting has anyone out there used and or are using the new dimlux expert series 1000 watt light , double ended bulb adjustable from 600 watts to 1200 watts.if so can you tell me the footprint they put out are and how you rate them , I been told you just put them at the top of your grow room and let your plants grow into them , to me this would cause streching and that’s not what we want can anyone help me here as they expensive to buy with the controller and all the sensors. Any help would be great as I can’t find any reviews on the Internet .

    63. Hello to all growers and future growers,
      just one comment and one question:
      The price for your seeds is NOT as important as customer satisfaction and support from a company that stands by there product and guarantees your shipment like these folks do !!
      look around at the competitors guarantee and you will see what i am talking about. my first order got snagged by the authorities. these guys re-shipped asap with no question. i was so impressed that i don’t even bother looking elsewhere ! do your self a favor and spent a few extra bucks and get the feminized seeds and no worries about male plants. even if you only got ONE OUNCE from a plant…that alone would be about a $300.00 value right there and you better get more than that or go back and read growing for Dummies…LOL. every seed i use has germinated so far without any problem.
      I have just one question to ask please. i live in an RV and had enough room for one 2×4 grow tent. i would like to be able to have some vegging while others are flowering. cant do that in the same tent obviously.
      can i veg my plants outside of the tent in normal day and night lighting as long as i provide the plants with high intensity 24 hours a day lighting closely above the plants and then move them into the 12 12 flowering tent when i harvest the ones that were in the tent ? secrecy is not an issue for me where i live and not afraid to have plants vegging outside of the flowering tent.
      PLEASE…i need the answer from a reliable source before i do something stupid and wasteful.
      Thanks in advance for any advice that you might have and good luck to you other new guys like me.
      Thanks again…Vern

    64. I’m feeling what you’re sayin, Marky! This is my 3rd AND BEST season, and tho I love the Growing Bible, am more inclined to let nature take its course with this weed. I have found the website immensely helpful for learning the ins and outs of growing weed and especially for general knowledge, before any issues arise for the plants.

    65. bought 3 seeds for 10. 00 per seed only 2 germinated 1 doing ok other trying to make it other never germinated very disapointed in the out come so far for the price of the seeds!

    66. […] By Robert Bergman, […]

    67. About 30 years ago I grew pot in a closet. There was some research about co2. At the time I was making wine and beer as well. Well, I built a frame out of wood. And on top of the plants I started making my wine on top of this frame. When alcohol is made from plants to make wine, the by product is alcohol of course and carbon dioxide. To make the wine it takes 6 weeks of constant co2 discharge from the demijon bottles. And since carbon dioxide is heavier than oxygen it just fell down amongst the plants in the closet. Never really share this with anyone until now but I grew some very very very good for the day. You might want to try this. Good luck. And let me know I’m curious.

    68. Thank you for your bible, as it really gave me a lot of information. I can get advice from friends ,but some times it can be confusing and conflicting. You’ve made it easier and a lot more understanding.

    69. It depends on what stage of growth you are in, and whether or not you oxygenate the res. Hydroponic nutrients should be changed every 7-10 days, and possibly as long as 2 weeks in veg, because the plants are not drinking much.

      Just a thought. If I were in Oregon; I would not be growing in a box or tent that limits my growth or yield. The box may be great for securely vegging plants, but I would give them space and better air by growing them in a small room.

    70. It is not recommended to remove all the leaves from a plant. This decreases yield.

    71. You only need to veg’ for 2 months. Your room mate was correct. You can veg ‘a Sativa longer if you want, but 2 months is generally maximum vegetation time. If you had a small yield after 2 months of veg’; It was because of inadequate lighting, and/or nutrients.

    72. I’m a first time indoo grower and I’m having fun doing it. I’ve been reading about the good affects of Co2 on growing, which got me wondering, isn’t club soda, aka carbonated water just water with Co2 injected into it? And I’m wondering if you watered your plants with the stuff now and then would the plants grow better?

    73. Good article, I have read your grow guide and it was really helpful, learned alot, my first grow was with potted plants, I germinated 10 bag seeds, 7 came out to be male, the others I just pulled for harvest, thanks for the info, I do have a question however, when looking at seeds under 100 magnification some of the seeds have fibbers or hairs on them that looks like the pistils on a female plant when flowering, why so?

    74. It has been years since I grew anything last, and so I started over researching and reading about everything all over like any other newbie grower out there. Thankfully your was the very first place I came to and begin ‘learning’ all over again, because no matter how many different places I’m going to and learning from, and how much I research a topic I always keep coming back to your information as to lining up with everything I already learned previously and finding the most informative and accurate information being written by you. The biggest problem I see everywhere I go to is that people just don’t research their problem(s) and expect others to answer it for them, and while I do days to weeks of researching things; I always keep coming back to you having answered the most common issues people run into for growing. Thank you so much for your time and putting these articles together, I am always looking forward to reading your next one. If just more people would come read what you’ve already written more people would be seeing more success in their grows!

    75. I subscribe to your site and explore others. I am a first-time grower and have read your recommendations. That said, other than the 12/12 advice, I haven’t done anything else that is advised. Not because I think this advice is not valid, but I treat my plants as I would any others because the growth process is the same.

      I wonder if people have forgotten that this is called “weed” for a reason. I am cultivating seeds that are 40 years old. Yep, 40 years! Back in the old days when seeds were a part of the stash, I collected them. I found those in a moving box a couple of years ago. I germinate and plant them. I’ve had a great harvest, tasty and potent.

      I just want to say that this growing “procedure” may be more technical than is needed, makes folks stress. A plant is a plant. A weed is a weed. I would welcome weed as opposed to the tumbleweed that I curse everyday!

      Keep on, you have good information, people will benefit from your knowledge. But remember that this is not rocket science, it’s growing weeds!


    76. Thanks, great info as I approach my first grow ever…Northern Lights, here we come!

    77. very informative. I chose the spicy mix pack for my potent strains. I will clone from these for years to come. Thanks Robert! Grant H. Oregon

    78. Thanks for all the help you provide. One problem I’m experiencing is obtaining seeds in the USA. Can you asdvise me on how to get my hands on seeds safely? I have run into dead ends constantly.

    79. Hi Robert. Ordering my grow cabinet soon. My question is that the hydroponic system that comes with the cabinet has room to grow 16 plants. The reservoir holds 20 gallons of liquid. I can only plant 4 plants legally in Oregon. With only 4 plants growing in my cabinet how often would I have to replenish the nutrients in that 20 gallon reservoir? Still once a week? Looking forward to getting my seeds from you.

    80. I’ve been growing for many years and the process I use I think you call “Supercropping”. I use the ties they use to put up chain-link fencing. They look like a shepherds crook.
      I begin early and use them to pin down the mail stalk till about 5 or 6 leaves and then bud it and do the same to the secondary branches.
      I let the 3rd branches grow straight up and bud them after 3 or 4 leaves and that’s it till mature.
      In the process I remove the shade leaves diligently and end up with buds and not much leaf.
      I smoke the leaf and that gives me an idea of potency.
      Hope this helps someone.

    81. Great information, only problem for me was; I’m on mobile Internet. ‘Cuz I’m on mobile the front of the email was cut off, but I could figure out some of the words that were cut off. I use your grow guide constantly when I did my first grow. Lol I yield very very low amount. My first problem was I didn’t have enough light n the I listen to my roommate n flowered after only 2 months of vegetation. When I start my next grow I’m definitely getting more lights n I’m certainly not going to listen to my roommate n let the plants vegetate for at lease 3 months. Keep up the great work you do with your web site, I certainly love all your emails 😉