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7 Best Organic Nutrients for Growing Cannabis 2021 — Reviews and Top Picks

Last updated: April 12, 2021

Best Nutrients for Growing CannabisEvery cannabis grower knows that there is more to growing healthy, happy plants than just soil, water, and lights. In order to grow the best plants possible, ones brimming with resin-rich aromatic buds, you’ll need to add high-quality organic nutrients into the mix. While your plants will still grow without these nutrients, you want them to thrive, and organic nutrients are the best choice you can make for your grow room.

 It can be a confusing process to choose the right combination of nutrients. Plants don’t need them every day, and the NPK ratios will vary according to your plants’ growth stage. Additionally, your growing method needs to be taken into consideration. Plants grown in soil vs. hydroponically grown plants have different nutrient needs.

If you’re feeling overwhelmed by the variety of available organic nutrients, don’t worry! We’ve created a list of in-depth reviews to help you decide which nutrients are right for you and your precious plants.


A Quick Comparison of Our Favorites

Image Product Details
Best Overall
Winner
General Hydroponics General Organics Go Box General Hydroponics General Organics Go Box
  • Wide range of nutrients to experiment with
  • Perfect for smaller grows
  • Affordable
  • Best Value
    Second place
    True Organic Cal-Mag True Organic Cal-Mag
  • Fully organic
  • Can be used in soil or hydroponically
  • Premium Choice
    Third place
    Eco Organics My Weed Minerals Eco Organics My Weed Minerals
  • 62 nutrients
  • Perfect for seedlings and clones
  • Stimulates trichome production
  • Cold War Organics Organic Fertilizer Nutrients Cold War Organics Organic Fertilizer Nutrients
  • Can be used for seedlings and flowering plants
  • Easy to mix
  • Lightweight
  • Fox Farm Liquid Nutrient Fox Farm Liquid Nutrient
  • Three different nutrients included
  • Great for all growth phases
  • The 7 Best Organic Nutrients for Growing Cannabis — Reviews 2021

    1. General Hydroponics General Organics Go Box — Best Overall

    General Hydroponics

    General Hydroponics provides you with all the nutrients your plants need in one convenient package. It features:

    BioThrive bloom: This is purely plant-derived source of essential trace elements, seaweed, and natural plant extracts. This is ideally applied in the flowering stages for fattening up bud growth.

    BioBud Bloom Booster: This will give your flowering plants an added boost when they need it most.

    BioThrive Grow: This works on the roots of your fragile seedlings, providing them with robust structure and assisting them in fending off disease.

    CaMg+: This provides high levels of calcium and magnesium to support the production of disease-resistant plants.

    BioRoot root booster: This supports the formation of roots in sensitive germinating plants.

    BioMarine Digested Fish Protein: These are quid-derived protein-rich nutrients for optimum early-stage growth.

    BioWeed Vitality Booster: Made from sea kelp, this fertilizer improves vegetative phase plant growth.

    Diamond Black: Also called diamond nectar, this helps increase your plants’ capability to absorb nutrients.

    This is a great starter pack for new growers, giving you a wide range of nutrients to get your plants going optimally.

    Pros
    • Wide range of nutrients to experiment with
    • Perfect for smaller grows
    • Affordable
    Cons
    • Small amounts of each product, so more suited to smaller grows
    • Not 100% organic

    2. True Organic Cal-Mag — Best Value

    True Organic

    Our pick for the best organic nutrients for the money is Cal-Mag from True Organic. This is the only fully organic source of magnesium and calcium on the market. True Organic boasts an “Organic Acid Complex” to provide high bio-availability and natural chelate minerals.

    Its organic mixture improves stalk and leaf growth and aids in preventing common deficiencies. It can be used in any medium and applied as a spray onto your plants’ leaves for optimal nutrient uptake. True Organics recommend one ml per gallon of water, making it extremely energy dense and efficient.

    It’s an affordable product that will give your plants a full array of micronutrients, including iron, sulfur, and zinc. Be aware that when it dries, it leaves a crusty material that flakes. So, when using on plant foliage, some cleanup may be required.

    Pros
    • Fully organic
    • Can be used in soil or hydroponically
    Cons
    • Not the full array of nutrients needed
    • Can be messy

    3. Eco Organics My Weed Minerals — Premium Choice

    Eco Organics

    Eco Organics “My Weed Minerals” contains ionic minerals that give your bud more resin production and higher potency. It contains an incredible 62 nutrients to give your plants all they need. Perfect for cloning and new seedlings, the high-potency minerals stimulate faster and thicker root growth. It can also be used as a foliar spray, and the minerals will not clog your spray emitter. This is especially useful in late-phase growth to stimulate trichome production and ultimately, more potent flowers.

    It comes in at number three because it is an expensive product, though it is well worth the extra cost if your budget allows.

    Pros
    • 62 nutrients
    • Stimulates trichome production
    • Perfect for seedlings and clones
    Cons
    • Expensive

    4. Cold War Organics Organic Fertilizer Nutrients

    Cold War

    Bud Bread from Cold War Organics offers all the essential nutrients needed, from seed through to harvest. Its organic clean-green-certified formula incorporates calcium, sulfur, and magnesium. It is an easy-to-mix powder, which makes liquid application and foliar application a quick and simple procedure. This added advantage makes it lightweight and easy to store.

    It has been tested on a variety of strains and produces healthy, potent yields time after time. Bud Bread is a strong product, so we recommend starting at a slightly reduced dosage and slowly increasing.

    Pros
    • Can be used for seedlings and flowering plants
    • Easy to mix
    • Lightweight
    Cons
    • Can harm your plants if applied too much

    5. Fox Farm Liquid Nutrient

    Fox Farm

    Fox Farm is a well-known nutrient supplier, and this convenient three-in-one nutrient trio is perfect for budding and experienced growers. For abundant green growth during the vegetative state, start with the “Grow Big” fertilizer. At the first sign of flowering, switch to “Tiger Bloom.” The “Big Bloom” is for use throughout the entire growth cycle for strong root structure and higher yields.

    Big Bloom is a natural and organic flower enhancer incorporating earthworm castings and bat guano to offer a full range of nutrients. Tiger Bloom is a fact-acting, ultra-potent fertilizer high in phosphorus and nitrogen for vigorous growth. Grow Big is perfect for early-growth seedlings packed with earthworm castings and Norwegian kelp.

    Pros
    • Three different nutrients included
    • Great for all growth phases
    Cons
    • Small bottles
    • Tailored more for soil use only

    6. Blue Planet Nutrients Easy Weed Soluble Seaweed

    Blue Planet

    This nutrient from Blue Planet is an organic powder-flake packed with naturally occurring growth hormones, trace elements, amino acids, and fully chelated micro-nutrients. Easy Weed is great for clones and seedlings and will aid in root-structure strengthening. It can be used hydroponically, in soil-less mediums like vermiculite and perlite, and in soil grows.

    Being a powder, it lasts longer and is easier to mix and has no odor. It is highly water soluble, so it can be used in a standard garden spray bottle. One 3.5-oz container makes up to 385 gallons of liquid fertilizer, so it is perfect for larger grows.

    Pros
    • Great for clones and seedlings
    • Can be used in soil and hydroponically
    • Highly water soluble
    Cons
    • Foliage applications can get messy

    7. Bloom City Organic Liquid Seaweed

    Bloom City

    This fully organic seaweed- and kelp-infused fertilizer from Bloom City incorporates seven different species of kelp. It has a unique processing technique to make the extract as clean and efficient as possible. This will give your plants all the benefits of kelp’s natural enzymes and hormones without the added non-nutritious fibrous pulp.

    Because plants love kelp, there is no risk of over-application. It can be used in all growth stages, from seedling to flower. Kelp is proven to aid in both root and stem strength and will give your plants big green leaves to help with photosynthesis. It can be applied directly to soil or used as a convenient foliar spray. Be aware that when used as a spray, this will make your grow room smell bad for hours!

    Pros
    • Seven different species of kelp
    • No extra pulp, so is highly water soluble
    • Little risk of over-application
    Cons
    • Smells bad!

    Buyers Guide

    With more new growers trying their hand at indoor cannabis growing, nutrient companies have sprung up enormously, with organic growing becoming more popular. It can get confusing trying to choose the right nutrients for your grow. Although cannabis relies on photosynthesis to grow optimally, a good soil or hydroponic nutrient mix is essential too. It takes more than just lights and water to produce resin-rich buds.

    Nutrient Ratios

    The first important consideration is nutrient ratios. To ensure optimum growth, your plants need the correct ratios of nitrogen, phosphorus, and potassium (NPK). When it comes to the application of these nutrients, there is no fixed universal ratio. This is because your plants need different ratios at different stages of growth, which is why the NPK comes in different blends. While nothing can beat experience, there are a few basic pointers to help you decide when and how much NPK ratios to feed your plants.

    At the vegetative stage, your plants will need to produce strong roots and stems in order to flower optimally. At this stage of growth, you’ll want to give them high levels of nitrogen, with moderate levels of phosphorus and potassium.

    In the flowering stage, your plants will need more potassium to help them bloom properly. This will ensure fragrant and resin-rich buds. You’ll want to level off on the nitrogen, as it can encourage too much leaf growth. Ideally, you want your plant putting all its energy into bud growth rather than leaf production.

    Nutrients for Growing Cannabis

    Micronutrients

    Your plants also need a variety of micronutrients to grow properly. These include iron, zinc, and copper. In general, an organic fertilizer is far more capable of delivering these essential micronutrients than chemical products. Although your plants don’t require a huge amount of these micronutrients, it’s a good idea to look for an organic fertilizer that includes them.

    In summary, you’ll likely need two different types of fertilizer during your plants’ entire growth life: one for vegetative growth and a second for flowering.

    Why Go Organic?

    Organic nutrients have several benefits over chemical fertilizers, especially within cannabis growing. While chemical nutrients will work faster and even increase the size of your plants, organic products will be superior in taste and aroma, every time. Additionally, you won’t have chemicals lying around your grow tent and being flushed through your system.

    Flushing

    A final important point is this: Don’t forget to flush! You’ll need to switch to plain water at least one to two weeks before harvest. This will flush out the fertilizers and prevent your buds from tasting like seaweed or squid.

    Conclusion

    The General Hydroponics Go-Box tops our list for its wide variety of nutrients and quality of products. It’s great for new growers and experienced growers alike and gives you all the NPK ratios and micronutrients your plants need for all phases of growth.

    The True Organics Cal-Mag is the best value for money, being the only source of truly organic magnesium and calcium on the market. While it doesn’t give you all the nutrients your plants need, it’s a great source of micronutrients at an affordable price and can be used throughout the growth cycle.

    Growing indoor cannabis can be a confusing and difficult process. All the right elements need to come together at once, which can be stressful. Nutrients are an important factor, and hopefully, we’ve made it easier for you to choose the right ones to grow your plants organically and optimally.


    Featured Image Credit By: Eco Organics My Weed Minerals, amazon