Easy tricks on Cannabis Soil you apply for better yields

Easy tricks on Cannabis Soil you apply for better yields

Mixing your own organic soil for growing marijuana is already a humble “scientific” job for a true hobbyist. Regardless of the expertise, you are having at the start, go on doing for in the end, your experience shall grow inevitably high along with the dope nugs, no doubt! If you are passionate enough, you shall be rewarded, this one always performs well.

This post contains the basic guidelines on how to design a soil mix for cannabis, what are the basic ingredients for the cannabis soil, and a few directions to keep it moving in the most enjoyable way possible. Do not forget to have a look at our guide on organic soil amendments to fertilize your soil naturally, and use the existing materials to rule the nutrition for your marijuana plants.

Any future buds start from soil:

“You will find only what you bring in.” – Yoda.

Ingredients for soil structure

Which ingredients do you essentially bring in soil to build its structure:

  • Sand and/or Silt.
  • Humus (this is soil per se).
  • Hydroton and/or crushed pieces of carbon.

The latter may be helpful in correcting a desperate situation of a heavy clay structure of the soil in your backyard, then adding sand may become even a harmful solution for the structural change.

How to make cannabis soil mix

The first and the most important step in making your own cannabis soil mix is the selection of the original soil, that you are going to modify. Don’t worry, this is not as sophisticated as it sounds. Just the best hint to picking a proper basic soil is to listen to what your heart desires. And, no, it’s not a master Yoda speaking again, but – you start from being comfortable yourself, also you utilize what you have read and heard about soil (called “unintentional knowledge” in brain-related sciences).

– Cannabis soil should be loose for the roots to strive in a comfort, and for oxygen and nutrients to reach the roots of marijuana plants freely. On the other hand, the soil should not be too loose to waste less water and nutrients dissolved in it but absorb everything properly. The extreme situation of water going through too easily is a hydroponic growing, a very different story.

– Cannabis soil should be rather coarse and grainy, and you avoid the fine ground. The fine ground, which may seem rich, loose, and of nice color, shall be tamped quickly with watering.

– Both provisions above work for water drainage. Marijuana plants have evolved mostly in dry regions, they hate over-watering. The water must go and still keep your cannabis soil moist.

If you buy the ingredients for your soil mix

In the market of the pro mix organic soils, even though all soils in grow shops are “cannabis soils”, some of them may fit your requirements or your character better, some are good for germination, another – for vegetation, and yet another – is for a lazy grower, etc. Pro mixed soils feature different contents and the purpose.

– Set eyes on the NPK of the soil, that will make your life easier then.

– Avoid clay soils. It’s hard to mess with this type.

– Loam soil is the best for marijuana.

– AP soil, all-purpose, of course, exists too.

How to choose the basic soil for the mix

Basic soil in your mix plays a vital role: (1) Potentially, it may contain (with luck) a fairly balanced set of nutrients, like silt soils; (2) Apparently, some types are close to impossible to pull through, like clay soils. For the case you have no intent to pick a commercially available mix of soil, but you wish to excavate a batch of random soil “from the garden” and make a perfect soil mix of your recipe, such may work, and for this, we have criteria:

  • Extend your search a little beyond your backyard. Better soil at your starting point shall require fewer soil ingredients (like sand, clay, etc) and fewer amendments (like nitrogen, magnesium, etc).
  • Skip the previous provision if you are sure about your garden soil, wish to experiment with the particular soil or any other reason you have for that.
  • Color and texture: the best colors are dark brown or almost black, dark red, and tan. The brown or black color of the soil indicates there is a high amount of organic matter, which is the main ingredient (humus) with all the NPK in it.
  • Test watering: pour a glass of water and watch how it’ll drain itself. There is no certain know-how but your own experience in comparison to different kinds of soil. Water should not disappear too quickly, and should not stay as a paddle on the surface.

Adding sand to cannabis soil for drainage

The dominating majority of the commercially distributed cannabis soils from the grow shops already contain sand mixed into them. Cannabis loves sand! Why do you need to add sand to your cannabis soil? Sand regulates the drainage properties of cannabis soil: the water should not transit easily, and it should not get stocked either.

Amending sand to cannabis soil prevents water stocking, as exceeding water may block roots from access to oxygen, then roots start rotting. Apparently, too sandy soil may lead to frequent watering, then, if your nutrients are dissolved in water, you risk wasting them as water goes through, and eventually impact your bill. If you have nutrients in the soil in a form of organic matter, like manure or coffee grounds, then the transiting water may wash out from the soil what should be kept.

That is why you need sand.

Grains of sand should be of a fair size.

F* that sand if its grains are almost flour.

Btw, if your approach is the laziest and the cheapest way (I did it a couple of times, and all went smooth) then – whatever soil you find, consider adding sand essentially. The only exception is clay soil, and there’s no other choice, and you skip adding sand, or end up with cement!! Read further to find out what to do then.

Adding silt to cannabis soil

Silt shares the properties with sand, except that it is mud. Silt shall not hold water for too long, just like sand saving you from over-watering, but not like sand it keeps nutrients much better. The pro mix organic soil ingredients are essentially sand and silt.

Due to its structure – minerals and organic particles – silt is fertile and helps your organic soil mix to stay moist with no excess water in it. Thus, silt soil is one of the best types of soil to start from. Also, idyllic for germination.

So, once you amend sand to your organic soil mix, then it should not be all sand, and silt shall be your next consideration. There is no universal bullet-proof recipe, anyway. To make the close-to-clay soil loose and moist I’ve amended a few handfuls of crushed carbon pieces once.

As a first-timer, do all your mixed soils wisely. If you have several pots, or several spots in the open air, like a garden or a backyard, consider differentiating the techniques for each plant. Then make notes and watch how your growing expertise produces the perfect recipe for the weed soil mix.

Clay pebbles aka hydroton for cannabis

Clay pebbles (hydroton) are multipurpose. A well-known fact they are essential for hydroponic marijuana, apart from that they serve perfectly the same purpose as sand in the soil mix. Hydroton pebbles are made of clay by heating it to a few thousand Fahrenheit, then clay fills with bubbles and transforms into small round units.

Hydroton clay pebbles for marijuana

Hydroton / Clay pebbles

Clay pebbles (hydroton) pros for cannabis

  • Clay pebbles, clay pellets, aka hydroton are offered in the market in various sizes, from 4mm to 16mm in diameter.
  • Clay pellets are easier than sand to apply: they weigh a few times lighter than sand, are relatively clean, and are practically designed to do the job nicely.
  • Pores in each such clay ball work for a better distribution of nutrients, water, and oxygen; compared to natural gravel which has no pores, does not allow water and air to go through.
  • Hydroton supports plant position, which is especially crucial if you mess with clones.

For normal weed growing (not hydroponic) fill in the bottom of the pot with pebbles at first. For outdoors, you can make a pit and fill the bottom with clay pellets. Such shall add to drainage, anyway.

Clay pebbles (hydroton) are in many ways better than sand as soon as they are designed for this.

Should there be any cons to clay pebbles?

The Moon, of course, has the dark side, and so do the clay pebbles for cannabis.

  • If you leave the whole system dry, the hydroton balls shall dry out too, and – when you add water back again – they’ll absorb the enormous amount quite quickly leaving nothing to plants. Watch it, also mean it when watering for the first time or after a dry period.
  • The real con is the price, but for smaller home systems it works.
  • Clay pebbles (hydroton balls) need to be sterilized once reused. This is critical.


Clay pebbles are fine, now let’s find out what is useful in natural clay for your marijuana crop. Clay is basically made of fine-grained rock material with a little quartz, fully loaded with aluminum and magnesium oxides. Clay is plastic when moist and hard when dry, it hosts the roots of your marijuana plants badly, including – due to the lack of ventilation.

If clay dominates in the soil of your garden or backyard, such is very close to a disaster. But clay works well as an ingredient in your perfect weed soil mix. You amend clay as little as 5-10% of the total soil mass to manipulate the overall ventilation property.

Well, what if you face a struggle, and there is no option but clay soil? Do not think you can just add sand, and voila, as you’ll only create an artisan cement.

– Add more humus to decrease the amounts of clay.

– Use crushed carbon and/or hydroton instead of sand.

We do not mean it is all clay as it is, but a heavy quantum of clay in your soil. Some plants are still growing in it, just marijuana plants are rather whimsical, and we need to please them.

Loam soil

Loam soil is a champion soil. It already combines sand and silt with smaller portions of clay and humus, of course. Loam soil is what you try to achieve when making your DIY organic soil mix, having no ready loam soil around. Needless to say, loam is the most desired weed soil to pot marijuana. It features good oxygen levels and excellent drainage properties, neutral PH, also naturally fertile.

Humus and manure

Humus is a “usual soil”, what we think when saying “soil”. Humus is the mix of organic matters like roots and dead plants, rotten to an end. Any normal grow shop, either oriented to marijuana or not, offers humus as the basic soil. Humus is the essential ingredient for your cannabis soil mix, and it takes the major share of the overall mass of your pro soil mix for marijuana. Hydroponic is an exception, of course.

If you are thinking to buy some ingredients for your soil mix, but not all, to leave space for the experiments, then a good investment would be buying humus – the basic soil ingredient.

Sometimes humus is called compost, but indeed compost is the mix of humus and manure. You amend both into weed soil if you have them around. Manure is worth looking for it. Bovines are poor digestives: they absorb roughly about 1/5 of what they intake, and the rest 4/5 of “yummy stuff” (including the NPK nutrients) goes into manure — marijuana plants shall be thankful!

Also, manure is great for making worm casting.

Worm castings for weed

Worm castings for weed (also vermicast or vermicompost) are earthworm’s poo. As worms travel through there under the surface they consume soil sending it through their digestion system, and what we get at the other end of a worm is what your marijuana plants would love to have!

You can buy worm castings as a ready thing in a grow shop, otherwise, you can pet worms in your place to produce worm castings for weed, or we call it vermicast. Compared to compost worms casting is easier to produce: worms require lower temperatures and deliver no smell. Despite that they are already crawling literally in bull sh*t, what we call manure, however, the additional smell is none, which we can hardly say about compost. Also, making worms casting is a significantly faster process rather than making compost, and requires less space.

Worms casting for weed is rich with elements, such as nitrogen, phosphorus, potassium, magnesium, and calcium. And you can apply worms casting directly to plants, compared that you mix manure with mud before you put it to plants. Messing with worms casting for weed is a cleaner job overall.

Common earthworm species used for the purpose are:

1) Red Wigglers, or Red Californian Earthworm.

Worm casting for marijuana, Red Californian Earthworm


2) Night Crawlers, these are larger.

Worm casting for marijuana, Night Crawler Worm


Worm castings improve the germination and all the weed growing;

Fertilizers you use with less fear about damaging the plant;

Worm castings hold water and nutrients;

Worm castings provide microorganisms and minerals to the soil, increasing the disease resistance greatly!

These worms are in the market, and they are good guys.

No PH problem ♥

For the marijuana plant soil PH level, where the best value is 5.5, the soil plays an important role. Especially indoors, where you emulate an unnatural system to be as natural as possible. Thus, a proper mix of soil may clearly demonstrate the concept “Just add water!” as it shall require significantly less (or not at all) nutrients. Even though adding some you only double-check on PH once in a while.

Just another reason to think about humus to buy, if you are a first-timer: the proper nutrients in humus from the beginning, may eliminate or reduce the marijuana plant soil PH level problem in the future. Nobody is there on the clouds with a PH-meter every time before it starts raining in the wild nature, because the natural soil “mix”, where the wild weed grows, is already perfect. Once you succeed with mixing the soil for your cannabis plants you’ll probably never come back to the “easy peasy way” anymore.

How much soil do I need to pot marijuana?

The roots of a cannabis plant require space. A common mistake is when roots go curving around in a narrow pot. You’d better give a lot of space, the first-class accommodation to your marijuana to flourish well. For one plant, the recommended volume of the pot is 2-3 gallons, which is from 8 to 12 liters. The pot is to be almost full of soil, so you need this quantum of soil mix for each weed plant on your marijuana plantation.

Wed, 11/Aug/21