Marijuana Nutrients and Marijuana Fertilizers

Marijuana Nutrients or Marijuana Fertilizer as it’s also known are effectively food for your plants. They are used to promote healthy and vigorous growth throughout the different stages of your marijuana plants life cycle.

If you want to grow healthy plants that produce big buds it’s important you understand when and what to feed your plants. If you don’t feed your plants with the right food they won’t blossom into the big yielding and potent plants you long for.

What are the main nutrients and what do they do?

There are 3 main marijuana nutrients a plant uses when growing, these are Nitrogen, Phosphorous and Potassium. They are usually labelled N-P-K and are universally presented in that order when written on the side of your fertilizer. (Picture of nutrients written on fertilizer bottle)

– Nitrogen (N) – Is the main nutrient responsible for leaf and stem growth during vegetative growth as well as overall size and vigor. Nitrogen regulates the plant’s ability to create new proteins, like chlorophyll and amino acids.
– Phosphorous (P) – Marijuana plants use phosphorous during flowering to produce nice big buds. Phosphorous is necessary for transferring the energy made during photosynthesis and is associated with resin and seed production.
– Potassium (K) – Potassium is used in all stages of a plants growth. Potassium encourages strong root growth, water uptake and triggers enzymes that fight disease.

When does your plant need nutrients?

A marijuana plant needs different levels of marijuana nutrients depending on its stage in the life cycle. Whether your plant is in vegetative growth or flowering will dictate which nutrients, and how much of them your plant requires.

Vegetative Growth
During vegetative growth you will want a nutrient solution that is high in nitrogen and low in phosphorus as during early phases of vegetative growth stem and leaf development are key to developing a strong and healthy plant.

During flowering you will want a high phosphorus and low nitrogen nutrient mix. A phosphorous rich mix help your buds swell, maximising the amount you can yield off each plant. It is possible to purchase specialist bloom nutrient mixes, which are manufactured specifically to increase bud size.

Bloom Nutrients

The table below shows you the ratios of Nitrogen, Phosphorus and Potassium needed for both vegetative and flower growth.

Nutrient Table
Grow tip: More marijuana nutrients do not necessarily mean bigger plants, so follow guidelines directly. Start with a diluted nutrient mix gradually increasing as the plant matures. If you are using too much or too little, your plant will tell you so keep an eye out for any leaf discoloration.

To prevent the accumulation of salts in your soil and to ensure that your plant is getting all of the food it needs you can begin leaf feeding your plant at the age of about 1.5 months. Dissolve the marijuana fertilizer in warm water and spray the mixture directly onto the foliage, allowing the leaves to absorb the fertilizer directly into their veins. You can continue to put fertilizer into the soil, but be sure not to overdose your plant as this may cause problems.

Grow Tip: As you add more and more nutrients, marijuana fertilizer salts will gradually develop in the soil, increasing the acidity and pH level. Also, as the plant gets older its roots become less effective in transporting food to the leaves, this can cause the plants growth to stunt and leaves to brown.

Medium – Soil and Hydroponics

The medium you use for your grow will directly affect the type of nutrients you use. There are specific marijuana nutrients for soil and hydroponic setups, so be careful you purchase the correct one.
Soil vs hydro

Soil as a medium contains a large number of the nutrients your plant requires during the growth cycle. As your plant grows the nutrients in the soil will be used up and so will need to be replaced using a fertilizer. The fertilizers replace essential nutrients in your soil to maintain vigorous growth and maximize your yields.

If your plant is being grown in a hydroponics setup, you will need to use specific hydroponic nutrients. These will include secondary nutrients and micronutrients that are found in soil but that need to be replicated in a hydroponic setup. They are important in producing a strong and healthy plant.

Grow tip: Be careful when using marijuana fertilizers in hydroponic setups. Many growers recommend using 80% of the manufacturer’s guidelines.

Secondary marijuana nutrients to consider!

The main secondary marijuana nutrients you need to consider are Calcium, Sulfur and Magnesium. Secondary nutrients are more commonly used in conjunction with hydroponic grows where there is a need to replicate the nutrients found in soil.

– Calcium (Ca) – Calcium is used by your marijuana plant for cell production and growth, maintaining healthy roots and ensures the proper flow of sugars and nitrogen.
– Sulfur (S) – Sulfur is used in the creation of many hormones and vitamins your plant uses throughout its lifecycle and aids the absorption of other weed nutrients.
– Magnesium (Mg) – Magnesium is an essential element for a marijuana plants light absorption, along side the creation of sugars and carbohydrates that are used in flower production.

Zinc, Manganese and Iron are the three most common micronutrients in your marijuana grow. Good quality hydroponic nutrient mixes will contain trace elements of the three, but always check the manufacturers bottle to ensure they are contained.

Most micronutrients are already present in a good commercial soil mix so check before you add any additional as too much will result in toxic levels which can kill your plant.

– Zinc (Zn) – Zinc is crucial for stem growth and is vital for sugar and protein production. Zinc deficiency is common in soil with a PH above 7.
– Manganese (Mn) – Manganese assists your marijuana plant with the utilization of Nitrogen and works alongside Iron in the production of chlorophyll which is essential for photosynthesis.
– Iron (Fe) – Iron is used by your marijuana plant to utilise the energy from the plants sugars, which are produced in photosynthesis, as well as the production of chlorophyll.
– Grow tip: Follow the manufacturer’s instructions without deviation as deficiencies are incredibly hard to decipher quickly and excesses of any marijuana fertilizer can kill a plant if not dealt with immediately

Glossary: Key terms

Below is a list of terms and definitions to help get the most out of your marijuana nutrients.

PH – The pH scale is used to measure whether something is acidic or alkaline. The scale works from 1-14 with 1 being very acidic, 7 being neutral and 14 being very alkaline. Most marijuana nutrientswork better within your plant at different pH numbers. However, this may cause them to “Lock out” other nutrients and the toxification of your plant. It is therefore best to keep your medium at a steady Ph; 5.8 for hydro and 6.5 for soil.
(Add pH scale image here)

PPM – PPM is otherwise known as Parts Per Million and is more commonly used by Hydroponic growers. It’s used as to measure the volume of a single nutrient in the water to work out the TDS.

TDS – TDS or Total Dissolved Solids is the total volume of marijuana nutrients in the water. It is important that throughout the different stages of marijuana plants life cycle, you do not exceed the amount of TDS it can handle, as you will either burn the roots or lock out the nutrients and starve the plant.

Marijuana fertilizers and nutrients can be a key part in your growing cycle. Ensuring you use them correctly and treat them with respect can help produce healthy plants and bumper crops.


45 comments on Marijuana Nutrients and Marijuana Fertilizers
  1. Lizzybear

    I would like to know if i could use rose pride fertilizer or if it would harm my plants….
    Also my plants have no leaves just buds….
    When do i need to cut the buda

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    Rating: -3 (from 15 votes)
  2. Mike Walker

    Iv’e read a lot.How tos, and comments.With all due respect some are well knowing on how to and I have always known chicken crap is king,fish if a American Indian says so then its so.Id like to thank the know hows for the advise and for the watch out for the 48hour curce.I don’t want crap.Im in it for the best I can produce.I feel like anything else theres no 1 way and moderation is best .Im beginning,But I am very seriously gona keep on.Thanks for the 3rd process of a plant that most think is done after the 1st harvist.

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    Rating: -4 (from 16 votes)
  3. Ericka

    What do you do if you accidentally feed your plants grow during the flowering stage? Are they ruined or will they hermaph

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    Rating: -8 (from 32 votes)
  4. chris

    In veg state do i want to have veg micro amd bloom together? During veg stage?

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    Rating: -5 (from 19 votes)
  5. Mark Cochran

    What light cycle and type of lights should I use in the veg cycle?

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    Rating: +2 (from 6 votes)
  6. russ clinton


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    newbie here! is it cool to pre~prepare nut solutn or does something spoil?

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    Rating: +3 (from 9 votes)
  8. Edward

    Instead of worrying about which brand to use, I would suggest checking the balances of Nitrogen, Phosphorus, and Potassium on the back of the product label. Use accordingly to whatever stage of growth your plant may be at.
    I would also suggest buying a pH meter to ensure you don’t burn your plants.

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    Rating: +12 (from 32 votes)
  9. mat mccormick

    Green Man,

    When should I change my nutrient level from high in nitrogen for the veg stage to high in potassium for the flowering stage? I’ve been able to sex my plant a couple of weeks ago determining it’s a female by discovering all the pairs of white hairs everywhere. Should I change to a flowering nutrient mix now or wait until I actually see buds forming? Any help in this would be much appreciated. FYI, I’m growing outdoors in Florida.

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    Rating: +17 (from 157 votes)
  10. Valerie

    Can I fertilize my plants with miracle grow

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    Rating: -10 (from 36 votes)
  11. pauline wyatt

    They are the most awesome plant I have seen grow.Good luck to everyone that loves to grow.Miracle grow seems to work just fine,just make sure you do not over water them.I would suggest only putting about a half a small bottle water a day,works great.

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    Rating: +1 (from 7 votes)
  12. chase

    I have a baby green cush clone it’s about 5in tall right now should I transplant it seems ready I’m a new grower in northern California

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    Rating: +2 (from 40 votes)
  13. tell me

    Do i need nutrients or can i grow it with plant food

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    Rating: -14 (from 74 votes)
  14. raw dope bmore

    i started late this year because i just came home from jail but for the past 7 years i been growing my herb in the window seal using natural sunlight and i grow it organically i water them with spring water and for fertilizer i use the allergy from my fish tank it provides nitrogen and many other useful nutrients from natural sources and also my turtles shit alot and piss and plus the food contains vitamins as well so it works great i once yielded 3 1/2 ounces from my sour diesel plant without ever using a chemical fertilizer ever

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    Rating: +7 (from 41 votes)
  15. cesar

    Im out in puerto rico ijust transfered my plant to my yard was growing on my patio advise any1 pls.

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    Rating: -2 (from 16 votes)
  16. victoria

    how often do i fertilise with sray and in pot i am a first timer my plant is in first blum

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    Rating: -1 (from 51 votes)
  17. G-money

    Newbie here….. Just started the veggie stage and was wondering when to worry about adding fertilizer. Growing indoors in soil

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    Rating: +11 (from 45 votes)
  18. Gonageh Hyman

    I have ten auto flowering plants between 6 & 8 inches tall, they are growing in fox farms ocean forest potting soil. they are very healthy looking. When do I need to fertilize them. I have some 10-10-5, but I don’t want to burn them up. any help would be greatly appreciated.

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    Rating: +15 (from 67 votes)
  19. Cici

    Okay So I’m a complete newbie at growing. I don’t have access to nutrients specifically Formulated for growing kick-ass weed. But I was curious to know if i could use Miracle grow for the nutrients that my babies need.. They make Two different kinds for vegetative and flowering plants.. could I use those and then be sure to flush the plants well when it comes time for harvest?

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    Rating: -9 (from 89 votes)
  20. marty bryant

    when is the best time to top my plants??they r a foot high,,i started them under lights and now i have transplanted to ground,,,,

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    Rating: +3 (from 37 votes)
  21. Green Man

    You want to avoid spraying marijuana fertilizers direct on to buds while flowering. It can leave buds tasting acrid and not very nice. It’s better for plants to absorb the ferts through roots as it has a better uptake and promotes more growth. You should stop using the nutrients and fertilizers around 2 weeks before and then flush as this removes any excess and improves flavour when drying / curing.

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  22. Justin

    If anyone has tried this, I thought it might work fairly well. I thought, to reduce buildup in the soil and maximize production, would it work out if you changed over to flushing the plant during the flowering cycle and just sprayed the fertelizer on the buds and leaves? Would that be TOO direct?

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  23. Green Man

    It really comes down to what you like. Only you know what you want to smoke/grow. The only advice we can offer is pick the plants that are the healthiest if you are planning to clone.

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    Rating: +2 (from 6 votes)
  24. Johno

    Been cloning and transplanting for about 9 months. I need to cut down on the numbers of plants I keep. Strain not withstanding, how should I make my decisions: Size; color; number of branches; size of leaves?

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  25. Green Man

    It is best to follow the instructions that come with your chosen nutrients as it’s important you keep the PPM (parts per million) accurate.

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  26. G. Frebusch

    green man, i am growing in a container about 3 gallons…i am one full monthinto flowering maybe slightly more. this is my first time and i know nothing…i flushed as you suggested and buds look great still have some yellowing fan leaves but still am looking for nutrients hard to find here.

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  27. Ricka

    How much all nutrient to add in wather how many millilitres mix?

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  28. Green Man

    Any good garden center or alternatively via an online grow shop.

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  29. joe silano

    Were can l purchase a good veging fertalizer l grow outside in the ground under a greenhouse tent and live in central Tx l’m having diffuculty getting my ak-47 fem auto taller than around 10″ hoping l can purchase some from this cite but only found flowering nutes above l currantly use llama poop tea ( llama shit from my herd aged three days in water) thanks in advance any help would be apprecatede

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  30. Green Man

    It sounds like you might be a little far down the line however the first thing i suggest you do is flush plant. Is the plant growing in a pot or planted in the ground? How far in flowering are you and how long do you have left? Secondly you could do with getting some flowering nutrients that are lower in nitrogen and higher in phosphorous and potassium.

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  31. G. Frebusch

    In addition I use miracle grow garden soil. I have had to repot three times and am now up to a 3 gallon container. I was afraid to repot while it is budding. can you do it without hurting the plant?

    I want to test pH but only have strips normally used in aquariums, can I bury a strip in damp soil to get a reading? the instructions on the container only talk about using in water.

    Thanks in advance for your help. I apologize if my questions are simplistic.

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  32. G. Frebusch

    I planted a seed from something outstanding 4 months ago and now own a grand 4 ft + tall christmas tree plant. It has been outside almost continually since the beginning and was the most beautiful plant I had ever seen. It is fully covered in bud and seems like it is going to produce well. However about 3 weeks ago it started to yellow and now the yellow leaves have brown along all the veins, first the fan leaves and now other smaller leaves. I remove the damaged leaves. I am afraid I over fertilized in the beginning and now too little after reading your section on nutrient numbers I know the miracle grow was a mistake at 24 – 8 – 16, and now my second choice is too low at 8 – 4 – 4. so my question is how can I fix this since I don’t have access to the prepackaged nutrients you recommend.

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  33. paul eriole

    what is secret engrediant used to help pot flower better

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  34. Green Man

    If you’re growing marijuana outside the plants should flower on there own thanks to the natural light/dark cycle of the sun. If you’re growing inside with lights you generally change the light cycle to 12/12 to initiate flowering.

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  35. Green Man

    This can be caused due a variety of reasons it can be nutrient burn or nutrient lock out. You will be able to find more detail on marijuana plant problems, including in Pest and Diseases and the Troubleshooting sections of our site.

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  36. BMF

    Outdoor plants which are 4ft .5 high,am feeding them chicken poop every 2 weeks.At what point do I change to flowering ?

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  37. Juju

    Great and very useful website, gets straight to the point! Anyways, is there a preferred cycle to promote growth? (e.g. day 1-nutrients, day 2- water, day 3- nothing) and any recommended watering/nutrient cycles for each stage? Cheers.

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    Not really, providing they get enough direct sunlight per day then there’s no reason to move them.

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  39. Keith

    I find the best place I can plant my plants are under Redwood and Sequoia trees. The trees are somewhat trimmed high enough to allow lots of sunshine. However, is it harmful to grow the plants under the trees?

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