“Organic” Marijuana Fertilizers

gore August 20, 2012 23
“Organic” Marijuana Fertilizers

Growing marijuana organically has never been easier. More companies are offering fertilizers made from naturally derived ingredients and better regulation on fertilizer labeling means growers can make informed decisions on what to feed their plants.

Before we begin this discourse on organic farming it is important to understand what makes organically grown produce superior. In studies conducted by several independent universities around the world, organic produce has been shown to contain up to 60% more nutrition over foods grown using “conventional” methods. In addition to being more nutritious, organic produce is free of trace levels of pesticides, fungicides and other potentially harmful chemicals that may have been used in their production.

Most pesticides that are indicated as “safe” for use up until the day of harvest should not be considered safe for use on flowering marijuana. This assessment of “safe” is contingent on the produce being washed prior to consumption, marijuana can not be washed properly.

Cannabis has the unique ability to thrive in toxic environments that prohibit the growth of other plants. Following the famous nuclear failures of Chernobyl, industrial hemp was planted to physically absorb dangerous radiation. Cannabis is like a wonderful sponge that greedily sucks up anything it can get its roots wrapped around. Because of this tendency, marijuana may be the most important candidate for organic production.

What is Organic Gardening?

The term organic, as it applies to this subject is defined by the United Stated Department of Agriculture or USDA;

“Organic is a labeling term that indicates that the food or other agricultural product has been produced through approved methods that integrate cultural, biological, and mechanical practices that foster cycling of resources, promote ecological balance, and conserve biodiversity. Synthetic fertilizers, sewage sludge, irradiation, and genetic engineering may not be used.”

There are several organic certification companies that are used by the USDA for testing fertilizer products. Collectively this federal entity is known as the National Organics Program or NOP. In addition to the USDA accredited certifiers there is the Organic Materials Review Institute or OMRI.

Being a revenue generating bureaucracy it’s all very complicated, confused with politics, money, and favors. Also, because of laws that protect trade secrets, fertilizer manufacturers are not required to list every ingredient in their products. Organic certification is expensive and companies that seek this golden seal of approval spend loads of money each year. In addition to this expense, the certification expires after a few years and manufacturers are forced to have their same recipes reevaluated.

Despite bureaucratic shortcomings, this complicated system used in the United States is the best in the world for protecting consumers from potentially harmful chemicals that can infiltrate food and medicine production.

List of OMRI certified products, sorted by company name (PDF)
List of OMRI certified products, sorted by category (PDF)

Traditional Organics

Before liquid organics, growers had a limited field of products to choose from. This often involved “building” ones soil by adding manures, composts, and other plant and animal byproducts. The items listed below are considered soil amendments. Amendments are best added to soil prior to planting, but can be worked into the soil around the base of established plants. The reference information below denotes one example of any given product, actual N-P-K values will differ by brand.


Amendment N-P-K Notes:
Blood Meal* 13-1-0 Rapid to medium release
Bat Guano 7-3-1 Rapid release, apply with caution
Seabird Guano 12-12-25 Medium to slow release
Chicken Litter varies by brand Rapid to medium release, apply with caution
Soy Meal 7-2-1 Vegan, medium to slow release
Fish Meal** 9-4-1 Rapid to medium release

*  Not suitable in areas where bears may be found.
** Attractive to bears and raccoons alike.


Amendment N-P-K Notes:
Archipelago Bat Guano 0-7-0 Medium to slow release
Belize Bat Guano 0-3.5-0 Medium to slow release
Philippine Bat Guano 0-7-0 Medium to slow release
Fossilized Seabird Guano 0-6-0 slow to extended release
Steamed Bone Meal* 1-12-0 medium release, delicious to bears

* Precipitated Bone Meal in not organic, “steamed” normally is. Attractive to bears


Amendment N-P-k Notes:
K-Mag Suppli-Mate 0-0-18 Water Soluble, INFO
Palm Bunch Ash 0-0-15 Alkalinity may adjust soil pH
Rice Husk Ash 0-0-15 Neutral pH, high in silica

Trace Mineral

Amendment N-P-K Notes:
Azomite Rock Powder 0-0-.2 Naturally occurring. mined, not processed INFO
Glacial Rock Dust 0-0-0 Slow release
Canadian Kelp meal 1-.1-1 Often high in humic acid and amino acids
TMI, Trace Mineral Additive 0-.5-.4 Derived from montmorillonite. Contains CA,Mg,Fe,Mn

“Organic” Fertilizers

Often, consumers think they are practicing organic gardening when they are not. While I am not a steadfast proponent of the industry’s current organic qualifying criteria, it is important to understand that OMRI and NOP make the final judgment. So seeing the little OMRI endorsement on the product packaging can actually be very important.

Despite the importance of organic certification there are some exceptions. There is at least one fertilizer manufacturer who has deliberately allowed their certification to lapse. The once certified Earth Juice Original product line has opted out of the organic certification rat race. Earth Juices recipes have not changed, so growers can still enjoy their liquid organic goodness. It is the opinion of this author that Earth Juice original formula Grow, Bloom, and Catalyst offer best in class performance and value.

Products With Misleading Labeling

Fertilizer companies are required to have obtained special certification prior to including the word “organic” on their packaging. However, some manufacturers print the word “organic” on their products as a misleading falsity. They are able to sidestep these regulations by placing the word “based” after organic. Actually the term “organic based” means the product contains a minimum of 15% organic matter, and should not be confused with organic fertilizers. Below are several examples products with misleading packaging.

  • Age Old Organics, Bloom and Grow
  • Botanicare, Pure Blend Pro
  • Earth Juice, Sugar Peak product line
  • General Hydroponics, Floralicious Plus
  • Superthrive

Not everyone chooses to grow organically. There are certainly pros and cons to this decision that can be debated ad infinitum. Please take it to the forum. That being said, the cannabis fertilizer industry is notorious for its confusing and gimmicky product packaging and we think it’s important to know what you are really putting into your plants. If there are any questions about the products mentioned here, or the countless others on the market, please leave a comment below and we will do our best to settle them.

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Rating: 3.4/5 (16 votes cast)

“Organic” Marijuana Fertilizers, 3.4 out of 5 based on 16 ratings



  1. sixfatbabies October 31, 2012 at 12:07 pm -

    Doe sanyone have experience with Bionova supersoil and bionova pk13/14??

  2. Weed eater February 20, 2013 at 7:26 pm -

    can homemade compost teas replace fertilizer

    • Rambo March 3, 2013 at 9:27 pm -

      Emphatically, YES!!!

  3. MomsBakedTreats March 18, 2013 at 6:57 am -

    what are your thoughts on red worm tea? I am new to growing and want to use my products in an edible line I am working on. Thanks in advance 🙂

  4. Chuck July 8, 2013 at 7:22 am -

    Check out MaxiBloom. Although not organic it’s very easy with great results. At a price you can’t beat. Use it in veg or bloom. It’s Lucas Formula in a bag.

  5. Daniel August 18, 2013 at 6:24 pm -

    The only nutrient that I see you guys have posted that is good is Superthrive. That stuff works great for veging 🙂

  6. cory September 2, 2013 at 9:35 am -

    i have a plant that 2-1/2 tall at only 2 months old an budding like crazy an my partener wants to pull it will it keep budding or shld i pull it any tips will help an it out side can i feed it to put out mor bud

    • Rambo September 3, 2013 at 12:19 pm -

      You should harvest it at full maturity and not before.

  7. Goo Ball September 12, 2013 at 6:51 pm -

    What is the best fertilizer to use in the late stages of the plants ? Thanks Goo!

    • Yoga March 31, 2014 at 6:32 pm -

      Fruit Bat Guano. I have access to the Rock Phosphate of this type from the Far East. Is there anyone who wants to import it by 20ft container load only. Price is $1.95/Kg.
      Contact me if you are interested. The going price for this item is $5.00+ per Lb.

  8. isaac September 17, 2013 at 6:49 pm -

    Has anyone used worm castings or a mix containing the castings as a natural fertilizer? I’m looking for new methods for future crops.

    • Rambo October 2, 2013 at 8:45 pm -

      yes, worm castings a great additive to you outdoor garden soil

  9. Bongsao October 15, 2013 at 9:09 pm -

    1st link is dead

  10. 1stblood November 21, 2013 at 7:24 am -

    I got 4 seeds from a friends little bag that I planted in a small cup of dirt leftover from a withered house plant.
    3 of the seeds sprouted, are now about 6 inches tall and a healthy green color.
    I’m writing to see if I can add something cheap and possibly readily available as a fertilizer?
    I’m currently broke and can barely afford food for myself so I hoping you can recommend something like coffee grounds or banana skins.
    I think the 3 plants are also outgrowing the cup they’re in so I’m also hoping you can recommend a bag of dirt I can order online.
    The plants are kept inside the apartment and I move them around to get as much sun as possible.
    At night I water them and put them under the small night light above our stove.
    They appear very healthy and seem to like being watered every night.
    I really enjoy helping them grow and the ‘Girl’ and I have even named them.
    Your recommendations would be sincerely appreciated.

  11. Caliber44 January 9, 2014 at 11:24 pm -

    In a hole about 15 inches deep and about 24 wide, put 4 inches of sand mixed with small stones, cut open a fish, place it in the middle and cover with 4 inches of sand, then put a mixture of half Miracle Grow, and half cow/horse manure, throw in some wood ashes for good measure…. Water regulary, and make sure its in all day sun… Watch and wonder !!

  12. Jenkins January 27, 2014 at 11:00 am -

    Sir Rambo…Would you suggest mixing an ultimate compost…exmp. hair, banana peels,egg shells,molasses, urine, etc etc…only to balance the ph levels of soil. I’m asking because I like the natural route and I did all of this before. I think I was lucky though with the measurements…All indoor.

  13. BONEHEAD April 19, 2014 at 6:39 pm -


  14. STONER April 22, 2014 at 12:10 pm -

    I know this isn’t about fertilizer but I have 2 LED lights one is 13 and the other is 23 Watts. How many plants could I grow with them.

  15. wave420 June 29, 2014 at 2:08 pm -

    lol bunch of noobs

  16. wave420 June 29, 2014 at 2:12 pm -

    @stoner if I was u I would only use the leds for vegging but even then I would run a t5 atleast along with those of course. then switch to a 400 0r 600 watt mh or hps for budding most people are atctually using the mh all the way through the bud cycle.ive used both and see not much difference.

  17. wave420 June 29, 2014 at 2:13 pm -

    @bonehead u either have autoflower plants or ur light schedule is out of wack.