soil additives for cannabis

How To Create Your Own Cannabis Super Soil Mix

Your buds are only going to be as good as the plants that bear them. And the best way to grow big, healthy cannabis plants is to use homemade super soil rich in nitrogen, phosphorus, potassium, and other vital nutrients.

Making a homemade cannabis super soil mix is much more rewarding than buying store-bought soil and bottled nutrients—and it’s not that difficult to make.

  • 1. What are the pros and cons of making your own super soil?
  • 1a. Pros
  • 1b. Cons
  • 2. Understanding soil and cannabis nutrition
  • 3. How to prepare your own cannabis super soil mix
  • 3a. Buy your base soil
  • 3b. Enrich your soil
  • 3c. Wash your super soil (if you want to plant right away)
  • 3d. Don’t plant directly into homemade super soil
  • 1. What are the pros and cons of making your own super soil?
  • 1a. Pros
  • 1b. Cons
  • 2. Understanding soil and cannabis nutrition
  • 3. How to prepare your own cannabis super soil mix
  • 3a. Buy your base soil
  • 3b. Enrich your soil
  • 3c. Wash your super soil (if you want to plant right away)
  • 3d. Don’t plant directly into homemade super soil

Store-bought soil works fine for growing cannabis, but it’ll only get you so far. To grow the best cannabis at home, we recommend always preparing your own soil. Keep reading for step-by-step instructions on how to prepare your own cannabis soil mix.


Like many aspects of growing, there are a number of pros and cons to creating your own cannabis soil. The pros, however, far outweigh the cons, and we encourage every grower to try preparing their own soil at least once.

• Good-quality homemade soil is rich in both macro and micronutrients, meaning you’ll be less reliant on chemical fertilisers.

• Growing with homemade soil gives you complete control over where your plants get their nutrients from. If you’re looking to grow organically, this is the way to go.

• Bud grown without chemical nutrients delivers a big, natural flavour like no other. A tastier, smoother smoke can be expected.

• The chemicals found in nutrient solutions create harsh runoff that can have a devastating effect on the local environment. On the other hand, using your own, homemade soil is completely sustainable and environmentally friendly.

• Preparing your own soil takes time, which is a luxury not all growers have.

• Preparing your own soil requires a larger initial investment than if you simply bought regular soil and a few nutrient solutions. Keep that in mind if you’re growing on a budget, but also remember that the results are definitely worth it.


Soil plays two key roles in the cannabis cultivation process. First of all, it weighs down your cannabis plants, keeping them rooted and protected against the wind. Secondly, and more importantly, it serves as a medium to transport nutrients and water to your plants’ roots. To better understand soil and how we can use a homemade mix to fertilise and nurture our cannabis plants, it helps to understand the basic nutrients cannabis plants need to survive and thrive.

Besides water, cannabis needs three main nutrients or _macronutrients_: nitrogen (N), phosphorus (P), and potassium (K). When you buy fertilisers, you’ll find products with varying concentrations of these nutrients designed to be used during different stages of the grow cycle. Here’s a brief rundown on how these nutrients help cannabis plants grow:

• Nitrogen is one of the main components of chlorophyll, and an essential building block of important amino acids.

• Phosphorus is essential for the production of ATP and phospholipids, which are used to build cell membranes.

• Potassium helps enable photosynthesis, regulates CO₂ uptake via stomata in a plant’s leaves, and helps strengthen cell walls.

Nitrogen, phosphorus, and potassium make up the bulk of the nutrients in most fertilisers you’ll find at a gardening store or grow shop. However, there are many other nutrients, known as micronutrients, that also play key roles in keeping your plants healthy and helping them produce the best possible buds.

Some of these micronutrients include calcium, iron, sulfur, zinc, boron, manganese, and copper, which you’ll find naturally in things like bat guano, worm castings, molasses, kelp, coffee grounds, and more.

When you prepare your own super soil for cannabis, you have the opportunity to prepare a rich medium for your plants ahead of time, rather than feeding your plants on an as-needed basis using chemical fertilisers. The hard work and effort you put into preparing your own natural and organic soil before sowing your seeds will pay off big time in terms of flavour and quality come harvest.


Preparing your own super soil might sound daunting, but it really isn’t. The concept is, in fact, pretty simple; you’ll start off with some good-quality organic soil and enrich it with natural ingredients ahead of time. Once it’s time to sow your seeds, you’ll have a rich growing medium ready that will provide your plants with everything they need to produce beautiful, aromatic buds.


Picking the right base soil for your cannabis plants is super important. Remember, cannabis likes well-aerated, permeable, and slightly acidic soil (pH of 6–6.8 is ideal). If possible, you’ll want to opt for an organic soil containing natural ingredients like worm castings, compost, coco coir, sand, and more. While these soils are generally more expensive, they’ll make a notable difference to the health of your plants and the quality and size of your harvest.

Some other ingredients to look for in organic soils include:

• Peat moss
• Guano
• Manure
• Rock dust
• Sand
• Coco fiber
• Natural fertilisers (like K-Mag)
• Pine castings
• Perlite
• Vermiculite

If you can’t find a good-quality organic soil with at least some of these ingredients, don’t fret. Simply go to your local nursery or gardening centre and buy a neutral potting soil. Again, opt for something slightly acidic if possible.


Start by placing your soil in a big container; break it up with a graip to ensure it’s well-aerated. Once it’s nice and loose, you’ll want to get to work enriching your soil with more natural ingredients to create a rich growing medium for your cannabis plants.

Some things to add to your soil include:

  • 1. Worm castings
  • 2. Coffee grounds and/or tea leaves
  • 3. Eggshells
  • 4. Vegetable and fruit peels
  • 5. Compost
  • 6. Coco coir
  • 7. Perlite
  • 8. Vermiculite
  • 9. Sand
  • 10. Bone meal
  • 11. Blood meal
  • 12. Rock phosphate
  • 13. Epsom salts
  • 14. Lime
  • 15. Dolomite
  • 16. Organic fertiliser pellets
  • 1. Worm castings
  • 2. Coffee grounds and/or tea leaves
  • 3. Eggshells
  • 4. Vegetable and fruit peels
  • 5. Compost
  • 6. Coco coir
  • 7. Perlite
  • 8. Vermiculite
  • 9. Sand
  • 10. Bone meal
  • 11. Blood meal
  • 12. Rock phosphate
  • 13. Epsom salts
  • 14. Lime
  • 15. Dolomite
  • 16. Organic fertiliser pellets

Simply add these ingredients to your soil and use your graip to combine everything properly.

The “correct” amount of each ingredient you use in your super soil will depend on the quality of your starter soil and how much time you have before planting. If possible, prepare your soil at least six months before you plant. That way, you’ll be able to use more of the ingredients listed above as they’ll have time to break down properly.

Once they do, they’ll create a rich topsoil for your plants, similar to what they’d have in nature. This super soil will be rich in nitrogen, phosphorus, and potassium, as well as all the other micronutrients we mentioned earlier.

This process, however, takes time. Compost, for example, can take anywhere from a few months to years to be ready, and you’ll need to take that into account when planning your grow. Vegetable or fruit scraps alone can take a few months to break down.

If you want to plant straight away, you can still use some of the ingredients listed above. You’ll just need to be more careful as you’ll be at risk of creating a really nutrient-rich (or “hot”) soil that can actually burn your plants. As a general rule of thumb to get you started, try using the following ratios of soil and other ingredients:

– 4 parts starter soil
– 1 part worm castings
– 1 part coco coir
– 1 part perlite/vermiculite (for extra drainage)
– 2.5–5% guano
– 2.5% bone and/or blood meal

When adding micronutrients like epson salts, azomite, lime, and dolomite to your soil, always read the package instructions. These nutrients are really strong and can cause nutrient burn when not used properly.


If you don’t have months to prepare your own super soil, here’s a simpler, faster way to prepare your own cannabis soil at home.

In the pots you plan to grow in, combine:

– 3 parts organic starter soil
– 1 part perlite
– 1 part worm castings
– ½ cup greensand
– ⅓ cup guano
– ½ cup dolomite lime

Mix everything together using your graip, then soak the soil for at least two days in pure water, keeping it wet all throughout. This will ensure your soil isn’t too hot for your seedlings. Allow the water to run off and the soil to mostly dry before planting. Once you do plant, make sure to use just plain water for at least the first three waterings.


It’s really important to note that homemade super soil is very nutrient-rich and shouldn’t be used for seeds, seedlings, or clones. These young plants are very delicate and will suffer from nutrient burn in such a hot medium. Instead, you’ll want to germinate your seeds and keep your young plants in neutral soil for at least the first few weeks, only transplanting them once they’ve officially started vegging.

Stop growing weed with crummy store-bought soil. Click here for step-by-step instructions on how to easily prepare your own cannabis soil at home.

Best Soil Nutrients for Cannabis?

Soil is so simple. So close to nature. Add seeds, remember to water your plants, and wait for an awesome harvest, right? Unfortunately, many growers run into problems with cannabis plants in soil. The culprit is almost always either your environment, watering habits, or nutrients/supplements. We’ve covered environment and watering habits already, so this cannabis soil nutrient tutorial will focus on which soil nutrients and supplements you need to get the results you want.

Recommended Soil Nutrients

Recommended Mineral-Based or Synthetic Soil Nutrients – This isn’t a comprehensive list of great cannabis nutrients, but these are the nutrient system I have experience with and recommend for growing cannabis.

Simple Duos – Use one bottle for the vegetative stage, and the other bottle for the flowering stage.

  • Dyna-Gro Grow + Bloom – Originally designed for orchids, Dyna-Gro nutrients have proven to work exceptionally well for cannabis plants in soil. If you want professional results without spending a ton of money or having to mix multiple bottles together, these two bottles give your plants everything they need from seed to harvest. The best simple duo in my opinion.
  • General Hydroponics FloraNova Grow + Bloom – Cheap and easy with excellent results. The biggest issue I have with these is the liquid is so thick it can be annoying to measure out.
  • Botanicare Pure Blend duo (or buy individually Grow + Bloom) – Consistent results every time. The Bloom formula is especially great.

Dyna-Gro Grow + Bloom is my favorite simple nutrient duo

Multiple bottles at a time – Typically there are 3 bottles for the base nutrients but sometimes only 2. This class of nutrients needs all bottles at all times, which get mixed in different ratios depending on the stage of life. More flexibility to alter ratios throughout the plant’s life.

  • Fox Farm trio for soil (mostly organic with some synthetic ingredients) – This is the first nutrient set I ever used for growing cannabis and I was thrilled with my results. They also offer a starter kit that includes their most popular supplements so you can try the entire nutrient line without having to invest in big bottles of everything.
  • General Hydroponics Flora trio – One of the most popular cannabis nutrient systems. Not just for coco and hydro, it also works great in soil! Follow the instructions on the side of the bottles at half-strength for cannabis plants in soil. This is my go-to nutrient system. Great growth rates, yields, and bud quality.
  • Botanicare KIND trio (it’s often cheaper to buy smaller versions of the bottles individually: Grow, Bloom & Base) – The 3 bottles provide everything a cannabis plant needs with more flexibility than the Botanicare Pure Blend duo.

You can’t go wrong with the Fox Farm trio for soil. Just follow the instructions on the label at half-strength for cannabis plants.

If using filtered or RO water (which contains few micronutrients) it’s a good idea to also add a Calcium/Magnesium supplement by the same brand that makes your base nutrients. Cannabis plants go through a lot of Calcium and Magnesium!

  • Dyna-Gro Nutrients – get Mag-Pro – Note: Don’t use regular Cal-Mag supplements with Dyna-Gro base nutrients as it can result in unwanted interactions.
  • Fox Farm nutrients – get Bush Doctor Cal-Mag – Note: they’re currently re-branding this supplement from “Gringo Rasta Cal-Mag” to “Bush Master Cal-Mag” and it can be difficult to find right now. If you can’t find the Cal-Mag version by Fox Farm, use Cal-Mag Plus. It won’t cause unwanted interactions with their base nutrients.
  • General Hydroponics nutrients – get CaliMagic
  • Botanicare nutrients – get Cal-Mag Plus

How to Adjust PH Using Synthetic Nutrients

  • Raise PH – PH Up
  • Lower PH – PH Down
  • …or get a PH Test Starter Kit that includes a small version of both bottles as well as drops to test the pH

Test and adjust the pH of your water to get faster growth and prevent nutrient deficiencies in soil

Organic Soil Nutrients

There used to be a ton of organic soil nutrients in bottles (like the now-discontinued GO Box) but many options have disappeared as growers switch to using amended compost for their organic nutrient needs. Why? The organic nutrients in bottles get similar results to mineral nutrients. The biggest difference in organic growing seems to come from using actual compost and/or amended soil.

  • Nature’s Living Soil (super concentrated organic compost nutrient mix) – amend bottom 1/3 of your plant container with this special organic amendment, and plants will be able to slowly use the nutrients “on-demand”. Even if your plants are already growing in soil, you can sprinkle a little of this on top of your soil and water to deliver organic nutrients. Note: smells strongly of manure!
  • Dr. Earth Organic Nutrients – dry nutrients
    • Vegetative Stage: Homegrown Tomato, Vegetable & Herb Fertilizer (better) or All-Purpose Fertilizer (good)
    • Flowering Stage: Flower Girl Bud & Bloom Fertilizer
  • Roots Organics Terp Tea Fertilizer Set (Grow & Bloom) – This dry formula is mixed with aerated water and brewed for 24 hours to create a “tea” for your plants. Can also be used as a top dressing.

Best supplement ingredients for organic growing

  • Sea kelp – a source of K, helps plants resist heat and stress
  • Leonardite – full of humic acids for happy roots, resist stress
  • Protein hydrolysate (contained in many supplements) – helps plants produce big roots and be more resistant towards water stress
  • Potassium Sulfate (also called “Sulfate of Potash”) – the sulfur and potassium promote smells and bud development in the flowering stage

My favorite organic supplement contains all: Floralicious Plus

How to Adjust pH in an Organic Soil Grow (regular PH Up and PH Down can harm the natural balance of the soil)

Organic cannabis growing is rewarding!

Summary of a Marijuana’s Nutrient Needs in Soil

Now that you’ve seen some suggested marijuana soil nutrients, let’s go through a quick overview of a cannabis plant’s life in soil as it relates to nutrient needs.

Seedlings Have Plenty of Nutrients in Any Soil

  • Get Set Up – Make a nice home for your plants to grow! Set up your environment for plants (closet, grow tent, etc.) and prepare containers full of quality soil. Great cannabis soil options: Fox Farm Ocean Forest soil, Roots Organics soil, Coco Loco soil. Consider a “just add water” organic soil.
  • Germination – At this point, there are plenty of nutrients in any soil mix. Your job is to water plants regularly without drowning them. Note: If you’re using a “soilless” potting mix, you will need to add nutrients from the beginning (soilless potting mixes don’t contain significant amounts of nutrients).

Just about any soil potting mix contains enough nutrients for seedlings

Soils Starts Running Out of Nutrients

  • Vegetative Stage – Fast-growing cannabis plants uptake way more nutrients than your average houseplant. Depending on how “hot” your soil was at the beginning (how full of nutrients), plants may start running out of nutrients during the vegetative stage. If you started with a regular soil potting mix, begin adding nutrients when plants are 3-4 weeks old to keep them growing fast and healthy. Plants want “all-purpose” or “grow” nutrients in the vegetative stage, which are high in all three macronutrients (high NPK). If you started with a big soil container or a hot soil mix like Ocean Forest soil, you may not need to add extra nutrients quite yet. Keep in mind than anytime you get runoff water out of the bottom of the pot, you’re washing away some of the nutrients. Therefore, it’s a good idea to avoid getting runoff unless you plan on adding nutrients in the water.

With many soil mixes, plants run out of nutrients and start growing slowly after a few weeks. When a plant looks lime green all over (especially if bottom leaves are turning yellow and falling off), it needs more nutrients overall. The left plant received plain water and started turning yellow after the soil ran out of nutrients. The right plant has been receiving nutrients in the water and is a nice healthy green color.

Major Deficiencies May Appear if You Don’t Add Nutrients

  • Flowering Stage – Cannabis plants devour nutrients when making buds, especially Phosphorus and Potassium (“PK”). As a grower, you must prevent nutrient deficiencies in the flowering stage or your bud quality and final yields will suffer. Many soil plants run into major nutrient deficiencies without extra nutrients in the flowering stage. At this point, you need to do one of three things: add nutrients to the water, apply a top dressing/amendment, or transplant plants to fresh soil. There’s one exception: If your plant has a “reservoir” of nutrients at the bottom of the pot (for example a bottom layer of heavily amended, composted soil), roots will dip in and take nutrients as needed all the way until harvest. This “super soil” strategy is the best way to grow cannabis plants if you only want to add water.

This flowering cannabis plant has several weeks before harvest, but it’s already losing bottom leaves and turning pale all over. This means the plant wants higher levels of nutrients overall. Without enough nutrients, more leaves will turn yellow and buds will stop getting bigger.

I gave the plant extra “bloom” nutrients (using the GH Flora trio). This reversed the yellowing and buds continued fattening. Here is that plant at harvest.

  • Harvest – If you’ve been adding nutrients and supplements to the water, it’s often recommended to give plain water for a week or two before harvest to “flush” the plants/buds, though some growers give nutrients until just before harvest. If you’ve been giving plain water from the beginning, nothing for you to do here; just wait until buds look ready and harvest!

Although you want to avoid discolored leaves for most of the flowering stage, it’s normal for leaves to start turning yellow the week before harvest.

Major Takeaways

  • Cannabis plants need a lot of nutrients for a good harvest
  • Nutrients come from either the soil or the water
  • If a plant uses up all the nutrients in the soil, you must add more
  • “Hot” (nutrient-heavy) soil mixes last longer
  • Bigger pots have more soil and therefore last longer
  • Runoff water washes away nutrients in the soil, so avoid runoff if not adding nutrients

How to Add Nutrients:

  • Transplant to fresh soil – a chance to start fresh, but can stress plants
  • Apply top-dressing or an amendment – nutrients flow to the roots when you water the plants
  • Add nutrients in the water – covered in detail above!

Alternative: Create a “reservoir” of nutrients under the soil (“just add water” setup )

Best Soil Nutrients for Cannabis? Soil is so simple. So close to nature. Add seeds, remember to water your plants, and wait for an awesome harvest, right? Unfortunately, many growers run into