Do you grow weed outside? Check out our ultimate guide on the best soil for outdoor weed, which nutrients to use, how to maintain the earth, and more! Additives that will help you improve soil quality, resulting in better growth cannabis. What to consider when it comes to growing weed in organic soil. Soil is the medium of choice for most cannabis cultivators. But what are the best soil for growing cannabis? This article answers the question and what you need to know to get the most out of your grow!
Best Soil for Outdoor Weed
You’ve got your seeds ready and feel excited about growing your first cannabis crop. What seemed like an easy task has turned into confusion, and a lot of questions pop up. What is the best soil for outdoor weed growing? Which nutrients work best? How do you maintain the ground?
Preparing the dirt the right way makes a massive difference to the quality and size of your weed. Not every plant is the same, and cannabis has specific requirements regarding the texture and type of earth.
You’ll need to develop the perfect outdoor cannabis soil mix for big, beautiful buds to flourish.
We understand that you might need some guidance to get things right the first time. We know you’re picturing yourself lighting up that first fat joint and don’t want you to be disappointed.
We’re here to help! Read on to learn everything you need to grow top-quality plants using the best soil for outdoor cannabis.
Starting to Grow Weed Outdoors Using Soil
There are many benefits to growing weed outside, including:
- Lower costs
- Big yields
- Environmentally friendly
- Fun and relaxing
Choosing the best soil to grow cannabis outdoors means you’ll need to stay on top of monitoring the acidity, texture, and pathogens (pests in the ground).
If you opt to make your own soil or purchase sterile earth, you’ll have complete control over the acidity, nutrition, and texture.
You need to be aware that planting weed in the ground gives your plants exposure to all the living organisms in the dirt, which is more challenging to create in a pot.
The container you grow your marijuana in is fundamental to the life cycle and harvest of your plant.
Wherever you decide to plant your weed, a well-prepared outdoor cannabis soil mix is crucial to mitigate any issues throughout the different growth stages. As long as you nourish the earth properly, your plant will thrive, and you won’t need to intervene.
Ultimately, excellent soil is the gateway to a healthy plant, which means an optimum harvest for you to enjoy to the fullest.
Soil Texture and Composition
The best soil for growing cannabis outdoors is light, loamy, and drains well but retains enough moisture. Loamy means a mixture of sand, silt, and clay with a ratio of around 40:40:20. The following make up the composition:
Cannabis plants need a specific type of soil to grow and flourish. You cannot just use whatever substrate you find. Even the standard garden soil sold in local stores will not suffice.
Ideally, the chosen mix should feature an optimal blend of light and heavy materials. This facilitates adequate water and oxygen intake. On top of that, it should contain a host of organic matter, making it hospitable to the microbial populations.
Soil can be broken down into four core components.
- 45% minerals (sand, silt, and clay)
- 25% water
- 25% air
- 5% organic matter
Sand is light, coarse-grained, and fast-draining. It primarily contains tiny fragments of rocks and hard minerals, such as granite, quartz, and limestone. The high porosity helps enhance the drainage and aeration of the mix. On the flip side, sand has poor moisture retention and little to no nutrient content.
Note: It is called “sandy soil” if it contains at least 85 percent sand and up to 10 percent clay.
Silt feels powdery when dry but slippery and mud-like when wet. It mainly consists of loose sedimentary material and rock particles that are much smaller than a grain of sand. It is not well-draining but has fantastic water retention properties. More than that, silt is also rich in nutrients and other essential minerals.
Note: It is called “silt soil” if it contains 80% or more silt and less than 12 percent clay.
Of the three types, clay has the smallest particles. Each grain is tightly-packed, leaving barely any airspace in between. The result is a heavy material that could store water and nutrients well. It is also highly fertile and contains a range of essential minerals. At the same time, though, being compact also makes it hard for moisture and air to pass through it. If there is too much clay, for example, the soil mix will not drain properly and may even turn concrete-like when saturated.
Note: It is called “clay soil” if it contains over 25 percent clay.
Water comprises about 25% to 30% of soil. It is not just plain water, however. Instead, it is referred to as ‘soil solution’ – water containing dissolved gases, salts, minerals, and organic matter. More importantly, it holds ions – the form of nutrients that the roots can absorb.
Just like water, nearly 25% to 30% of soil exists in a gaseous state. These gases fill the pore spaces in the soil. Note that soil naturally contains high amounts of carbon dioxide – but low levels of oxygen. That is why it is important to boost aeration in the root zone. Remember, plants need oxygen to convert sugars into usable energy – a process known as respiration.
Soil is made up of about 5% organic matter or carbon-based compounds. That refers to any living material – including plant and animal debris – at various stages of decay. Although the organic content is relatively small, it still plays a critical role in the quality and quantity of the yields.
The millions of microorganisms in the soil – such as bacteria, fungi, protozoa, arthropods, and nematodes – are responsible for breaking down the once-living biomass. In other words, organic matter serves as the food source of these microbes. Along the way, it produces and synthesizes nutrients, making them more available to the roots. At the end of the decomposition process, what you get is humus – a dark, spongy material teeming with nutrients.
The main benefit of organic matter is that it enhances soil tilth – the soil’s physical condition, especially its ability to support plant growth. In particular, it boosts aeration, water absorption and retention, and drainage, among others. It also serves as a nutrient reservoir.
What exactly is loam, and what is so special about it?
Technically speaking, loam refers to soil containing less than 52% sand, 28% to 50% silt, and 7% to 27% clay. For gardening purposes, the most popular sand-silt-clay ratio is 40:40:20. The proportions, though, may vary, resulting in different soil subtypes.
|Types of Loam Soils||Mineral Composition|
|Sandy loam||Sand: 43-85% Silt: 0-50% Clay: 0-20%|
|Silt loam||Sand: 0-50% Silt: 50-88% Clay: 0-27%|
|Clay loam||Sand: 20-45% Silt: 15-53% Clay: 27-40%|
|Sandy clay loam||Sand: 45-80% Silt: 0-28% Clay: 20-35%|
|Silty clay loam||Sand: 0-20% Silt: 40-73% Clay: 27-40%|
The unique mineral composition of loam soil significantly impacts its texture, drainage, and water retention – in a good way.
As a combination of sand, silt, and clay, loam soil contains multi-sized particles. If you run your hands through the material, it should feel dry, soft, and friable. More importantly, it should maintain this consistency when dry and wet, making it easy to handle and work.
When compressed into a loose ball, loam should retain its shape for a moment before breaking up into chunks. That is a sign that it has an optimal texture – neither too compact nor too loose. Having enough airspace in the soil is critical as it allows the roots to grow through it. At the same time, it also boosts oxygenation while promoting drainage.
Having sufficient drainage helps prevent overwatering, which could drown and suffocate the roots. And without enough oxygen, the roots will starve and begin to decay. Eventually, this leads to nutrient deficiencies.
Loam soil has enough sand to make it well-draining. That is because the gap between the particles allows water to percolate through it. After watering, the pool on top of the medium should drain within a few seconds. Neither should it take too long to trickle out of the bottom holes.
Water Retention Capacity
The main concern with sandy soil is that it is fast-draining. It runs the risk of drying out, but it could also flush the essential minerals. That means that the plants may not have the moisture and nutrients they need to grow and prosper. If left unaddressed, this could stunt growth and cause other damage, compromising the yields.
Loam soil does not have drainage issues due to the addition of silt and clay – both of which are water-retentive and can negate the high drainage capacity of sand. Ideally, it should absorb and hold onto moisture without getting too muddy.
The Ideal Soil Amendments
Loam soil – regardless of the type – is by no means perfect. Depending on your needs, preferences, or situation, you might find it lacking in some aspects. Or, maybe you did not achieve the optimal sand-silt-clay concentration. At any rate, you will most likely want to improve its physical, biological, and chemical makeup.
Soil amendments – which include both organic and inorganic materials – could help you achieve precisely that. Ultimately, they help maximize plant growth and productivity.
Organic amendments come from materials that were once alive. These include compost, earthworm castings, and animal manure. They increase the organic matter content in the soil, dramatically improving tilth in the long run. Most of these materials have nutritional value, which is why they double as organic fertilizers.
Inorganic amendments, on the other hand, are usually mined minerals, such as perlite, vermiculite, pumice, and limestone. Generally, they improve the structure of the soil, particularly aeration, drainage, and water retention. Others help stabilize the pH or even add minerals.
Here are some of the most popular soil amendments and their specific purpose:
|Primary Functions||Soil Amendments|
|Improve Texture||Gypsum Coco coir Biochar Perlite Vermiculite Pumice Compost Earthworm castings|
|Boost Drainage Ability||Gypsum Coco coir Biochar Perlite Pumice Compost Earthworm castings|
|Increase Water Retention Capacity||Coco coir Biochar Vermiculite Pumice Compost Earthworm castings|
|Add Organic Matter||Biochar Compost Earthworm castings Chicken manure Blood meal Bone meal Bat guano Crustacean meal Fish emulsion Kelp meal Alfalfa meal Mycorrhizal inoculants Humic acid and fulvic acid|
|Adjust or Stabilize the pH Level||Biochar Garden lime Compost Bat guano Blood meal Humic acid|
Note: You have the option of starting with loam soil and amending it with the preferred ingredients. Alternatively, you can also buy organic potting soil from trusted brands. If the product contains any of the above amendments, you can expect that it has a decent texture and composition. Despite having nutrient-rich materials, though, you would still need to use separate nutrients across the different growth stages.
Planting in Pots or in the Ground
Once you’ve got your soil mix for cannabis outdoors ready, you’ll need to determine where you’re going to plant your weed. There are two primary options, pots or in the ground. Both methods have their benefits, so it’s up to you to decide which works best.
If you opt for pots, you have the advantage of using commercial soil, which, luckily for you, tends to be optimized for growing cannabis and is pre-sterilized. This earth keeps harmful microbes away and your plants well-nourished.
There’s a downside, though. Your plants will be constricted within the container and may also require transplants and lots of watering.
If you want to go all-natural, your plant’s roots can spread out and access the maximum amount of groundwater. Your cannabis will grow bigger and require far less maintenance, but there’s always the risk of exposure to pathogens in the soil and contamination.
The seasoned weed growers may make it seem near impossible to create the best soil for cannabis outdoors, but fear not! Marijuana will grow almost anywhere, even on riverbanks.
Make sure to watch your plants as they grow and adjust the soil when needed. Producing cannabis is a learning curve that you need time and patience for. The best way to learn is on the job.
Best Soil for Growing Weed Outdoors
We’re sure you’ve heard the phrase, ‘you are what you eat.’ The same applies to your cannabis seeds and plants, which is why quality soil is essential. The better the earth, the better your final harvest will be, and the more you’ll enjoy it.
What is the best soil for outdoor weed growing? It depends on where you plant your cannabis.
Best Soil for Growing Weed in Pots
When planting your seeds in pots, you have complete control over what goes into the mix. You can buy a commercial branded soil that’s all ready to pop your seeds into, or you can opt for some homemade compost.
For first-time cannabis gardeners, investing in quality potting soil is the best idea. Marijuana outdoors grows with watering alone if you use the ‘super soil’ correctly without having to add any minerals or nutrients.
You can make this earth yourself with a combination of worm castings, bat guano, and other components. Let it sit for a few weeks with some quality soil, and it’ll be good to go. We recommend adding a few stones to help with drainage.
Best Soil for Planting Weed Seeds in the Ground
The best soil for weed outdoors when planting in the ground is loam, which we mentioned is a mix of sand, silt, and clay.
Test your soil with the glass jar method to check the ratio of each element and amend accordingly. You’ll also need to consider certain factors, including:
- pH level
- Water retention
- Nutrient makeup
A clay-heavy soil will drain slowly and won’t hold oxygen well. Dig large holes at least a month before you plant and mix in plenty of compost, worm castings, manure, and other organic matter. This technique allows for aeration, drainage, and lots of nutrients.
Sandy soil is easy to manipulate and drains nicely, but it doesn’t hold nutrients well. You’ll need to dig holes and add compost and peat moss to bind everything together.
Silty soil is ideal because it’s simple to work, holds moisture, drains well, and has lots of nutrients. This dirt is also very fertile and will welcome your seeds well.
Ideally, your outdoor soil mix for cannabis should be a blend of them all. You can add in store-bought earth with added nutrients to help maintain your plants healthy until harvest. Ensure you add fertilizer and sterilize the dirt if you don’t use a commercial brand.
The Best Nutrients for Outdoor Soil Growing
For your seeds to grow to their full potential, your earth will need three essential nutrients. The best soil to grow cannabis outdoors should include the following in the fertilizer.
This nutrient is the most essential for your plant’s growth, food processing, and chlorophyll creation. You’ll notice a lack of nitrogen if your cannabis starts turning yellow and stops growing taller.
When your soil doesn’t contain potassium, leaves will turn light green to yellow. The nutrient aids proper growth and helps with the reproduction of your plant. Potassium also affects the shape, size, color, and taste of your weed.
Playing a vital role for seedlings and young plants, phosphorus helps cell division, promotes root growth, and aids the development of the growing tip.
How to Get the Best Soil Mix for Cannabis Outdoors
As mentioned earlier, you can buy a soil mix or make your own. Here are a few things to consider and look out for in either situation.
Buying Pre-Made Soil Mixes
If you decide to buy the best soil for outdoor weed from your local garden store, you’ll come across a variety of amendments, such as:
- Bat guano
- Peat moss
- Plant food
- Worm castings
- Bone meal
- Fish meal
- Glacier rock dust
If the brand amends the soil heavily, there’ll be a huge list. Others create great structured soil with basic nutrients, leaving gaps to fill yourself.
When looking for something that’ll help you throughout your plant’s life, opt for dirt that offers the correct pH level, balanced nutrients, and a loamy texture. This way, you won’t need to do a lot, if anything, yourself.
If you like the idea of creating your soil mix but would like a little help, purchase a customizable option. With these bags, you can add your topsoil and liquid nutrients when you want, depending on your weed’s needs.
Creating Your Own Outdoor Cannabis Soil Mix
Perhaps you decide to create your mix, so you’ll need to do a bit more work to keep your seeds happy. To make the best soil for growing weed outdoors, you’ll need to assess your current dirt first.
Once you’re satisfied, you’ll need to look for a quality fertilizer to provide your plant with the three essential nutrients. The less nourishment your weed gets, the fewer buds it’ll produce.
These nutrients need to be present throughout each growth stage, which means a lot of maintenance on your part.
Keep in mind that shop-bought soils come already sterilized, which kills harmful bacteria, fungi, and insects. For your seeds to flourish, thorough sterilization is a must.
The process takes a lot of time and effort, though, and there are other ways to control your pests by introducing beneficial microbes and insects into the soil.
How to Feed and Maintain the Best Soil for Outdoor Weed
Once you’ve started growing marijuana outdoors, you need to know how to feed and maintain your beloved plant. Neglecting your cannabis at any stage will result in poor quality weed or, even worse, losing your entire harvest.
Throughout your marijuana’s lifecycle, you’ll have to ensure it gets enough nutrients. You can buy ready-made mixes in a store or create your fertilizer. If you want to make organic food for your cannabis, we recommend these:
- Blood meal or fish meal for nitrogen
- Bone meal or bat guano for phosphorus
- Wood ash or kelp meal for potassium
- Dolomite lime for calcium and magnesium
- Epsom salts for magnesium and sulfur
We advise against nutrients designed for indoor growth as they tend to contain synthetic mineral salts, which are damaging to bacteria in the earth.
If you’re not sure how much fertilizer to use, it’s best to be conservative. You can always add topsoil if you notice deficiencies in your plants. There’s such a thing as too many nutrients, which could cause a nutrient lockout and ruin your crops.
Growing Weed Outdoors in Soil is the Most Natural Way!
By now, you should know enough to prepare the best soil for growing weed outdoors to plant your seeds for optimum growth successfully. Cultivating weed is an enjoyable pastime and highly rewarding when you finally sit down to light up and try your cannabis.
Remember, whether planting in pots or the ground, buying ready-made soil, or mixing your own, have fun and spend lots of time with your cannabis.
Once you’re ready to get started, shop for seeds and begin your marijuana gardening journey. Don’t forget to share stories and let us know how you get on!
Best Soil For Cannabis – What is Good Soil For Growing Weed?
Signs of good and bad soil quality, other additives that help to improve soil quality and what to consider when it comes to planting this year.
- 1. The benefits of organic soil
- 1. a. Organic soil additives
- 2. Other additives that improve soil quality
- 2. a. Coco
- 2. b. Biochar
- 2. c. Perlite
- 2. d. Vermiculite
- 3. Signs of good soil
- 4. Signs of bad soil
- 5. How to make your own soil
- 5. a. Best nutrients for soil
- 5. b. Cheap mix for diy soil
- 5. c. Best soil for beginners
- 5. d. Ph too high or ph too low
- 5. e. Best soil for marijuana
- 6. In conclusion
When growing autoflowering Cannabis plants, it is very important to keep them supplied with nutrients in the form of hard foods, or liquid feeds. The best soil for autoflowers will depend on your environment, fertilizers, and ability to control the pH, so keep this in mind if this is your first grow cycle, knowing the best option in your case can really set you on your way to bountiful harvests.
So if you’re wondering what soil is best for growing weed, below we’ll explain what to know, the signs of good and bad soil quality, as well as what you should consider when it comes to planting this year.
1. The Benefits of Organic Soil
Soil for autoflowers or for any other type of cannabis plant consists of organic material that is in a permanent state of decomposition. Teaming with beneficial microorganisms that are responsible for converting nutrients to the plant’s roots, living soil is Mother Nature’s way of allowing autoflowering plants to work in a symbiotic relationship. As the tiny microorganisms decomposing the organic matter, they make the nutrients available for the roots, which are now able to access all the available nutrients and minerals found within the soil web. Once this symbiosis occurs, then the only real requirement is for the soil to be adequately watered. This is basically the most simple form of organic growing that is perfect for those new to growing, it requires very little maintenance, and labor, as well as allowing the grower to work with a slow buffering organic process, so if you were wondering what is the best soil for growing weed, read along.
Organic Soil Additives
Using organic soil additives or amendments will help increase the number of beneficial microorganisms, improve moisture retention, and help you control the health of your soil. In general, you should be looking at adding these amendments before planting. They will help you create the best organic environment for the root system to thrive, which will result in amazing growth and the full terpene profile maturing.
Bat guano is one of the most widely used additives in cannabis cultivation. It is a fast-acting, highly bio-available organic fertilizer with high rates of nitrogen and phosphorus making it perfect for the vegetative growth stage. It also helps improve the drainage and oxygenation of the soil mix, helps boost the natural immunity against pests, fungal infestations, and disease, and can ensure the best possible terpene production (although there is little scientific evidence to back up this claim).
Be careful with the amount you introduce to the substrate, as bat guano is pretty strong stuff. A little goes a very long way.
It can be used in both its fresh or dry form and is typically sourced in either powder or pellet form. It can be used in many ways other than as a direct additive to the soil. Many cultivators used bat guano as a fertilizing tea, or as a foliar spray. It can also be used as a top dressing by sprinkling it directly around the base of the plant and then watered in. To make a super effective bat guano tea all you need is 15 grams of bat guano, 1 liter of lukewarm water, and an air pump. Mix the guano and the water together well, and make sure the water is only lukewarm. Hot water will kill the microbial life that you are trying to introduce to the mix. Give it all a good mix, throw the pump in and let it aerate for at least 24 hours. This tea can be supplied twice a week throughout the entire lifecycle of the crop.
Worm casting, or worm poo, is literally the most bio-available organic fertilizer with ridiculous levels of both nutrients and minerals. Also referred to as vermicast, this top-shelf additive is perfect for any organic cannabis garden. It not only provides long-lasting, slow-release nutrition to the crop but also increases the aeration of the soil and provides excellent drainage.
You can swap out any potting mix you may use for 100% worm castings, and you do not have to worry about nutrient burn issues at all. Creating your own worm farm at home is super simple and can provide you with an unlimited supply of castings, ready to use at a moments notice, and provide your crop with almost everything it needs to provide you with bumper harvests.
Cow manure makes a perfect slow-release fertilizer. It usually contains a very well-balanced mix of the three main macronutrients that plants need for healthy and vigorous growth, plus manure works as a very efficient soil conditioner and helps increase the amount of microbial life in the soil, while also boosting moisture retention. Keep in mind that some manures may have herbicide contamination, so always check the packaging to ensure it is fully organic. If you live near a farm and can get it directly from the source then even better!
You want to mix the manure in before planting, and make sure there is no heavy rain forecast for the next week or so to prevent the chances of all the goodness being washed away. Chicken manure, on the other hand, is considered to be “hot” manure, meaning it can easily burn the plants if not allowed to sit and mature. In general, we do not recommend using chicken manure for your cannabis crop.
Bone Meal and Blood Meal
Bone meal is made from the ground-up bones of beef cattle and is a fantastic source of both phosphorus and calcium. It is used pretty extensively with outdoor cannabis cultivation but is not recommended for indoor growers. It does come with quite an acidic pH level which needs to be balanced, so keep that in mind. Blood meal is made from, you guessed it, the blood of beef cattle. It is very rich in bio-available nitrogen, but can also easily burn the plants if overused.
It too comes with quite an acidic pH level which must be balanced. Both of these additives can attract the attention of wild animals which can easily wreck the crop, so make sure any plants that use these amendments are well fenced off. It goes without saying that these additives are anything but vegan, so if that is important for you then choose other fertilizing options.
Kelp meal is one of the most desirable additives for cannabis crops, as it is packed full of over 65 different essential elements and minerals, and also contains a very healthy dose of potassium. Many growers are of the thinking that kelp meal provides a huge boost to the flavor and color range of cannabis, which we agree with.
Every single cannabis crop, no matter the method or techniques applied, should have mycorrhizal fungi added. This type of fungi plays a very important role in helping the plant feed on the nutrients by turning them into a more bio-available source. They also help protect the root system from attack by pests, disease, and harmful fungi.
2. Other Additives That Improve Soil Quality
One of the downsides to using soil found in the ground is that it can be very dense once watered. Restricting root growth during the early stages of a Cannabis plant’s life is never advised, so adding other substrates into your living soil can be very advantageous.
By simply adding a 25-50% ratio of coco coir to your cannabis soil, the quality of the mix will become very airy and lightweight. Adding coco will enhance the air pockets present, the wicking action of the medium, as well as encourage a mass expansion in the rhizosphere. Coco is very user-friendly and is well associated with large yields. The best thing about adding coco is the fact it is an inert growing medium, so does not have any nutritional value in terms of Nitrogen, Phosphorus, or Potassium, including trace elements.
- Increases aeration and holds water better: Due to its characteristics, coco fiber can increase aeration in the soil and can absorb up to 10x its own weight in water, making it vital for growers living in dry weather.
- Cheap: Coco fiber is relatively cheap and comes in various forms. You can find it compressed into a brick or already washed and ready to use out the bag, the price may change a bit depending on your preference but it won’t be absurdly expensive.
- Easy to use: Coco is a sterile medium so fungus and other bugs avoid it, making it perfect for growing cannabis. Also, because of its neutral pH, you can use it with soil amendments without worrying.
- Sterile: Because this type of medium is sterile, it won’t contain any of the nutrients your plant needs, even though you can mix it with soil or even amend it, you will have to provide all the nutrients your plant needs if you’re only using coco.
- Needs to be washed: The quality can vary from brand to brand, so depending on the brand, you will have to soak it and wash it a couple of times to remove impurities before using it.
- Hard to find good quality: Even though it’s relatively easy to find coco coir, it can be hard to find good quality coco fiber. This doesn’t mean you can’t use it but you will have to wash it thoroughly and experiment with a couple of brands before you’re 100% satisfied.
An incredible organic addictive that has amazing water-holding capabilities, an enormous surface area, and is a source of pure carbon. Biochar is made by heating wood to such temperatures that the end result is a tiny, charcoal-black crystalline substrate. Due to the fact it is 100% carbon and has a shelf life of thousands of years, organic farmers use biochar with their soil to improve water retention allowing for less watering times, feeding the beneficial microorganisms a rich source of carbon, and helping save the planet.
Organic additives like Coco Coir and Biochar can drastically improve the quality of your soil, improve water retention and not to mention help you to save the planet.
- Increases soil fertility: Biochar can boost soil fertility when used in combination with amended soil because it prevents nutrients from leaking out and provides carbon which increases the availability of nutrients in the medium.
- Holds nutrients and moisture: Thanks to its porous surface, biochar can absorb a lot of water and draws in minerals which are essential for plant development.
- Reduces the need for fertilizers: Because biochar is carbon-rich, it accelerates the decomposition of organic matter which results in more nutrients being available in the medium, a perfect choice for organic growers.
- Can affect yields: Due to the porous characteristic, biochar can absorb too much water and nutrients when used in excess and can end up stressing your autoflowering plants which will show signs of deficiencies.
- Can be contaminated: The quality of biochar is influenced by the material it is made of, so it can come contaminated with heavy metals or harmful compounds that are bad for your autoflowering plants.
- Harmful to humans: If not dealt with caution, you can end up breathing ash which is a concern if exposed to daily, also, it can irritate you if it comes in contact with your eyes or skin for a long period of time.
Perlite is usually used in soil mixes to increase aeration and improve the soil’s texture, by using perlite in the proper amounts you will not only improve drainage but also avoid compaction, making it a better medium for the roots to grow in. Usually, perlite is used in combination with coco fiber and soil to provide the best medium for the roots, while perlite improves aeration, coco fiber absorbs water, balancing those two elements in the best ratio possible.
Perlite can also be used to plant clones in, when you place your cuttings in perlite, the roots usually grow stronger and faster because they need oxygen to thrive and perlite helps provide it.
- Increased aeration: Perlite creates small air pockets in the soil so if used properly, it can improve the growth rate.
- Sterile medium: Because it’s a sterile medium, perlite won’t affect the pH of your medium or increase the amount of minerals in it.
- Avoids soil compaction: Perlite needs to be thoroughly mixed in the soil before using, this will create several air pockets that make the soil fluffier, avoiding compaction.
- Can dry the medium faster: You will need to check your autoflowering plants closely because with more oxygen in the soil you will have to water more often.
- Needs to be washed first: If the brand you’re using does not pre-wash the perlite, it may come with a fine dust that can be harmful if inhaled so we recommend washing your perlite before using.
- Needs to be watered more often: Because the medium will dry faster, you will need to water more and this means you will need to check on your autoflowering plants at least 2 times per day to make sure everything goes accordingly.
Vermiculite can be used to improve the quality of your soil, just like perlite, vermiculite has several qualities that will make your autoflowering plants grow better and faster. This mineral helps aerate the soil, holds water and nutrients while not being toxic or changing the pH.
If your soil is compact or does not drain water properly, you can add vermiculite to provide the roots a better medium to grow in, just make sure you’re using the proper ratio because too much can hold a lot of nutrients and water and end up harming your autoflowering plants.
- Neutral pH: Because it’s a sterile medium, vermiculite will not alter your soil’s pH so there’s no need to worry about checking the runoff every day.
- Can prevent mold: When used in the proper ratio, vermiculite will absorb the excess water, preventing mold and fungus in the soil.
- Improves soil quality: Just like perlite, vermiculite improves the soil’s texture and makes it fluffier, preventing soil compaction.
- Can be expensive: Depending on where you live, vermiculite can be relatively hard to find and a bit expensive because it’s not usually found in regular grow shops.
- Can affect autoflowering plants if used in excess: Because perlite holds nutrients and water, using it in excess can ultimately result in overwatering and overfeeding.
- It’s said to be harmful: When buying low-quality vermiculite, it can contain asbestos and can cause lung problems. Inhaling these tiny fibers can cause asbestosis, mesothelioma, and lung cancer if exposed for a long time so it’s essential to buy the best quality possible and wash it before using it.
3. Signs of Good Soil
Due to the process in which soil is naturally produced, there are a few factors to consider if you are going to prepare your own. If buying soil from a well-known brand, or your local garden center’s cheap and cheerful products then there are some things to consider.
- Check the packaging to see the nutritional value of the soil. A good brand will take the time to display a soil nutrient analysis displaying-N-P-K values, amount of perlite, vermiculite, compost, trace elements, and the bacterial and fungi count present.
- Worms aerate the soil as they crawl through eating up organic matter. If you see your soil full of worms then do not worry. Not only will these little helpers aerate the soil but will release beneficial bacteria from their gut as they do.
- Good store-bought soil will have perlite or coco added allowing for the ideal balance of air to water retention. Avoid soils that do not have any perlite unless you are purposely buying pure worm castings.
4. Signs of Bad Soil
- Bad soil will have an unpleasant smell which is a red flag bad bacteria are present, causing the medium to be in an unfavorable acidic state.
- Drainage will be poor, causing the soil to become dense and heavy. This weight can restrict root growth and slow plant development down dramatically. The ratio of water retention, drainage, and wicking capabilities will all be out of balance.
5. How to make your own soil
To make your own soil mix you need to have in mind the conditions that you will have during your growing cycle, things like temperature and humidity may have an influence in the best mix, so make sure you know the conditions before mixing your soil.
Best nutrients for soil
We recommend always using organic nutrients when growing in soil because soil it’s organic matter and contains microorganisms that can greatly benefit your autoflowering plants if taken care of properly. We cannot recommend a certain brand or organic nutrients line but as long as you’re using high-quality organic nutrients and use them appropriately, you’ll be fine. Just make sure the nutrients are 100% organic and keep an eye on the pH level because a drastic increase or decrease can ultimately kill the microorganisms present in your soil.
Benefits of good quality soil and what to keep in mind when you’re looking for the best soil for cannabis possible.
Cheap mix for DIY soil
Even though you can find organic nutrients in your local grow shops, they can be quite expensive so if you’re on a budget there are good alternatives that are relatively cheap.
There are several other methods to make your own organic nutrients such as KNF and Bokashi.
Depending on the space you have available, you can try composting or vermicomposting, these methods allow you to make your own tailored organic soil that will provide everything you need without spending too much.
Best soil for beginners
If you’re a beginner grower and don’t know exactly how things work, here is a general soil recipe that will work fantastically in almost all types of weathers, just remember that as time passes and you get more experienced, it’s ideal you adjust it to your specific needs.
General DIY soil recipe mix:
- 80% organic soil
- 10% perlite
- 10% coco fiber
Remember that you can and should tweak it to your needs, but as long as you maintain a similar ratio your autoflowering plants will grow exceptionally.
PH too high or pH too low
If the pH of your medium is too high or too low, you should check the nutrient solution you’re feeding, have in mind that most additives are sterile and neutral so if you’re experiencing pH problems you should check the water source and nutrient solution.
Best soil for marijuana
The best soil mix for autoflowers or best marijuana soil, in general, will depend on the weather you have throughout your grow cycle, by following the table you can easily choose the one that better suits you.
|Advantages of soil additives when growing autoflowering plants|
|Additive||When to use||Advantages|
|Coco fiber||Use in dry environments or to improve soil quality.||Holds water and helps avoid soil compaction.|
|Biochar||Use in dry climates or when growing in organic soil.||Improve water retention and helps decompose nutrients faster.|
|Perlite||Used to help aerate the soil in humid environments.||Helps dry the soil faster and increases aeration.|
|Vermiculite||Used in dry environments, helps keep the soil moist.||Improves soil quality and helps keep it moist.|
As a general rule, you should always use 70-80% of organic soil mixed with the additive of your choice, always have in mind to use additives with different properties, for example, vermiculite shouldn’t be used with coco fiber because both absorb a lot of water and can cause overwatering.
- 70% organic soil
- 15% perlite
- 15% coco fiber or 15% biochar or 15% vermiculite
For the best soil for autoflower plants, we recommend using 70-80% organic soil mixed with 15% perlite and 15% coco fiber, or substituting coco for vermiculite or biochar, always respecting their properties to avoid having oxygen or water in excess. Remember that for the best growing medium for autoflowers, you should be on the lookout for the tips your plants give you and adjust the ratio if needed.
6. In conclusion
There isn’t a best soil for weed, in general, having all of the nutrients covered is one-half of a top-quality soil for marijuana, however, it should also have the ideal ratio of drainage, air pockets, and wicking action so we recommend looking into super soil for autoflowers.
Once you have found the ultimate balance, you can now confidently re-use your organic growing medium for multiple crops with the understanding the more time the living soil food web has to develop, the greater the results in terms of plant performance and yields.
How To Choose The Best Soil For Growing Cannabis
If you go to any cannabis trade fair you will see all sorts of different companies promoting a litany of products, from the most recent tents, to advanced hydroponic setups, to the latest in lighting fixtures and the best soil for growing cannabis. This can be intimidating for some, as many of these products seem quite advanced and expensive, however growing good cannabis can actually be surprisingly easy. That is of course, if you do what nature intended for cannabis, namely provide a solid foundation in the form of some good old-fashioned soil.
You can endlessly argue back and forth as to whether you get bigger and better yields from growing hydroponically, in a greenhouse, or indoors, but the most trusted names in the world of cannabis cultivation will almost always tell you that nothing beats cannabis grown in some simple dirt. Your growing medium will always play one of the biggest roles in terms of quality of the final product and perhaps the biggest argument for choosing soil over hydroponics is terpene production, which is where organic soil shines. Sorry hydroponics-lovers, but you’re just not going to get those terpene-driving microbes in your nutrient solution no matter how hard you try. Organic soils, particularly of the no-till variety, are vast oceans of microbial life that provide nothing but the best nutrients for your plants in symbiotic fashion and your plants reward you for that in the form of delectable, fragrant flower.
Not all soils are equal and in many cases some work will have to be done to give your plants what they need so that you can have a bountiful harvest. Thankfully, putting together some good-quality soil is not rocket science and most of the required ingredients are readily available at your local gardening shop, though there are a few basics you should consider when deciding on a particular soil.
Drainage, Texture, and Water Retention
Proper drainage is an absolute must in order for water, nutrients and air to reach the roots of your plant, so consider a soil with the right texture, that is not too compact or dense so as not to asphyxiate the plant’s roots, which would end your gardening activities before plants can develop. A light and airy soil is ideal, however, on the flip side you want a soil with good water retention as well. If your soil is too loose, you will end up having to water it constantly, which means you run the risk of your plants drying up if not careful. Too much water in the soil, especially the top layer, will also attract pests and pathogens, such as fungus gnats and mold, so you want to find that sweet spot where your soil is moist enough for roots to develop but dry enough to prevent mold from forming.
The Optimal pH Level
Another important factor to keep in mind is soil pH. Different soils can vary as far as their pH levels are concerned, but that won’t stop them from producing high-quality cannabis. As long as they fall within the range of 5.8-6.5, they should do just fine, though optimally you want to aim for 6.0-6.3). Anything beyond that will likely require intervention by the grower so as to avoid issues such as nutrient lockout and deficiencies, which could severely affect plant growth.
Nitrogen, Phosphorus, Potassium: Key Cannabis Nutrients
This also ties into what you feed your plants in the form of additional nutrients and fertilizer. A good soil should have a healthy amount of the three basic macronutrients: nitrogen (N), phosphorus (P) and potassium (K). Without these three, your plants will wilt and yellow, eventually becoming too weak and sick to fully develop. Depending on the plant’s stage of life, the required N-P-K ratios will vary, but a ratio of 3-1-1 in the vegetative stage is a good rule of thumb.
Soil For Outdoor/Indoor Cannabis
Cannabis connoisseurs swear by outdoor, sun-grown cannabis and it should come as no surprise that “all natural” cannabis is said to be the best tasting with some of the most magnificent effects, however not all outdoor cannabis is the same. If the choice is made to grow outdoors, growers have two options, namely growing directly in the ground as nature intended or in pots/beds using a blend of ingredients for the soil. When growing directly in the ground (especially using the no-till method), the plant should have all the basic nutrients it needs provided the soil hasn’t undergone erosion. Some growers choose to supplement such plants with amendments like compost, manure and other organic fertilizers with very good results, but considering cannabis has thrived for hundreds of thousands of years without human intervention, there’s a good chance it will perform well without much amending.
Indoor growers have more options as far as choosing their soil composition goes, especially these days where buying good quality soil is just a few clicks away. There are also plenty of soil mix recipes available online so growers can experiment with different ingredients to see what blend will work best, though all-organic soils and/or ingredients will give you the most rewarding results. Regardless of what type of soil you choose for your indoor grow, make sure it is light and airy enough to allow for your roots to breathe. Remember that roots also need air, so if possible avoid using plastic pots. Not only will they keep air from getting into the soil, they can also absorb heat, particularly if black, and potentially cook the plant’s rhizosphere, which could easily ruin your harvest. Use fabric pots/grow bags or air pots to make sure plant roots are getting the oxygen they need.
Autoflowers & Seedlings
Seedlings and autoflowering plants can be kept in the same type of soil as photoperiod plants, however the lower the nutrient content, the better in this case. Seedlings are particularly sensitive to nutrient overload and autoflowers have a very limited vegetation period, which means they will not have much time to recover before the flowering period kicks in, should there be some sort of nutrient imbalance. As a result, you want to avoid overloading your plants with food (nutrient burn) to the greatest extent possible. Regardless of the type of plant or soil, less is more. Nutrient deficiencies can be easily corrected, nutrient excess is more difficult to remedy.
Recommended Best Soil For Growing Cannabis
If you feel inclined to buy a ready-made soil from an established producer, there is a multitude of options available online as well as any decent growshop/gardening center. Just make sure that you are buying an organic potting mix. A good soil should be dark, loose and not clumpy or muddy. If it has perlite/vermiculite/coco coir mixed in, all the better as this provides good drainage as well as water retention. Fox Farm, Roots Organics, and BioBizz are trusted brands that provide good results, whereas BioTabs distributes good-quality organic supplements and fertilizers should you choose to take this route.
Super soils are a great option as they eliminate the need for feeding your plants liquid nutrients. The only liquid they will need is water, beyond that you won’t have to do very much to achieve respectable results. An online search will give you loads of different recipes, so feel free to dig around and find one that suits you best. Having said that, your super soil base should be comprised of the following: coco coir, perlite, vermiculite, and compost and/or worm castings.
There are many additives to choose from to make a nutritious living soil your plants will really love, but the most common ones include activated charcoal, coffee grounds, mycorrhizae mix, bat guano, dolomite lime and kelp meal. Simply combine the base with the additives and mix thoroughly to remove any larger clumps and presto you have yourself a solid super soil that only requires occasional watering.
Many growers experiment with and tweak their recipes, so there is no perfect formula. You may have to play around with ingredients for a while before finding the mix that works best for you, but remember not to get too carried away, as cannabis will respond negatively to nutrient excess and imbalances.
To sum it up
The beauty in growing cannabis in soil is that the simpler you keep it, the better your plants will respond and the easier it will be to identify and address the plants’ needs. Organic soil is widely believed to be the best medium for cannabis plants, just as mother nature intended it to be. Not only will your plants be happy, but so will you, provided of course you give them what they ask for, no more no less. Happy growing!