Been trying to figure out what is the best soil for cannabis? Not sure where to start? Read on to learn more about different soils and what's right for you. If you have an indoor cannabis grow set-up, you need the best soil for growing weed indoors. Our guide dives into what factors to consider and the best ones. Prepping the soil for an outdoor cannabis garden makes all the difference. Learn about the small details that make a high-quality harvest.
Learn now how to choose the best soil for growing cannabis
Most weed gardeners know that growing cannabis in soil is a common and effective growing method.
The difficulty is that growers have to peruse through many soil options and may find it challenging to determine the right option for them.
Well, sit tight! In this article, we’ll be showing you how to choose the best soil for cannabis to give your marijuana the best chances of fat buds and a huge yield.
Why is choosing the best soil for cannabis very important?
Soil is one of the three components (including water and light) needed to help a plant
Choosing the best soil is vital as, without it, a plant can’t grow effectively and may end up lacking nutrients or even under developing. Good earth also helps provide plants with the health needed to survive under challenging weather conditions.
Along with learning about temperature and humidity for growing weed, understanding soil is vital. It spells the difference between a plant that didn’t grow to one that exceeded expectations.
The components that make up the soil
Soil consists of several components and is quite complex in its makeup. Let’s look at what these are:
- Air: 25% of soil is simply air.
- Water: A further 25% of the earth is water. It’s vital for moving nutrients to the plants.
- Clay: One of the three primary materials found in soil, clay, like the other minerals, is derived from broken-down rocks.
- Sand: This is one of the primary minerals found in dirt. Minerals, in fact, make up 46% of all soil.
- Silt: The second of the primary minerals found within the soil.
- Organic matter: This makes up the remaining 4% of the earth. Soils high in organic matter are brilliant for plant growth.
Knowing what good soil is
You can identify excellent cannabis soil by looking at a few key indicators.
- Dark and loose: Dark soil is rich soil. It means that they contain plenty of organic matter, sodium, and healthy nutrients. Loose soil allows for better aeration.
- Good drainage & water retention: Good drainage means that the marijuana water can drain to the bottom well. Well-drained earth ensures that your cannabis stays wet for a reasonable amount of time. An appropriate amount of water retention is vital to keep cannabis healthy.
- The correct pH value: The ideal pH value is about 6.0 as cannabis plants thrive better in a slightly acidic environment.
- Organic matter: Organic matter is decomposed material derived from plants and animals. It helps provide nutrients and improves the water holding capacity of the soil. Examples include compost and manure.
Choosing the best soil for marijuana
The best soil depends on the conditions that you’re growing your marijuana. So, for example, what’s needed for outdoor marijuana is different from that for indoor cannabis.
Let’s break it down.
Best soil for outdoor cannabis
The benefit of growing cannabis outdoors is that your plants won’t be as restricted and can further grow their roots.
However, you’ll have to monitor and possibly change the soil’s pH level if it’s not suitable.
Cannabis plants all need nitrogen, phosphorus, and potassium in their soil ‘diet’. These nutrients will be absorbed at different rates and need to be renewed with a good marijuana fertilizer from time to time.
A dark, crumbly loam works best outdoors that’s mostly silt.
Best soil for indoor cannabis
Loamy soil is the best for indoor cannabis. An ideal mixture of 40% silt, 40% clay, and 20% sand offers a loose soil texture for adequate oxygenation and root growth. This mix also offers good water retention, drainage, and an ideal pH level of 6.0.
Best potting soil for cannabis
Firstly, it’s important to note that no matter what pot you use, always make sure that there are holes at the bottom to prevent your cannabis from drowning.
Cannabis can be effectively grown in pots using pre-packaged organic soil.
An alternative is to make what is known as a ‘super soil’ mix. You’ll have to find a super soil recipe or order a mix online. It’s a great option as it self-regulates its pH levels.
Best organic soil for cannabis
Creating the best organic soil for marijuana is tricky, but there are a few components that can drastically improve its health and efficacy:
|Component||What it offers|
|Worm castings||This is a good source of nitrogen. It’ll also give your soil the added benefit of many micronutrients.|
|Bone meal||For a source of phosphorus, this is the way to go.|
|Chicken manure||Chicken manure is an excellent source for adding nitrogen and phosphorus to your soil.|
|Bat guano||This is also a good way to get phosphorus and nitrogen into your organic soil. It also diversifies the soil’s bacteria.|
|Compost||Compost piles can be an excellent source of nutrients such as potassium.|
|Kelp meal||Both promoting microbial diversity and offering potassium, kelp meal is a great component to add to organic soil.|
Best soil for autoflowering cannabis
Autoflower cannabis seeds transition automatically from the vegetative to flowering stage regardless of the light availability.
However, for this type of cannabis, light and aerated soil is preferred. This aids the roots in growing deeper.
You can make the best soil for autoflowers from peat moss, compost, vermiculite, and coco coir.
Store-bought vs. homemade
If you’re not interested in the hassle of putting together your own soil, then you can always stop at a local shop or peruse an online store for some good-quality mix that’s ready-made.
Although homemade soil may lack on some fronts, it does offer certain benefits. Let’s take a look at what those are compared to store-bought:
|Homemade Cannabis Soil||Store-Bought Cannabis Soil|
|Greater flexibility of choice.||Already pre-packaged.|
|Generally cheaper than store-bought cannabis.||More expensive than homemade cannabis.|
|It requires more research to figure out and can be complicated.||The work to put together nutrients and research is already done for you.|
|Easier and cheaper to make in bulk.||Often comes in smaller packaging.|
How to make your own soil
Making your own soil may be preferable for many as ready-made soil mixes can be pretty expensive. Here are a few steps that you can follow to get started:
Step 1: To start with creating your marijuana soil mix, you can opt to find soil at your local gardening store. Alternatively, you can use the soil you have at home.
Step 2: Next, you’ll need to add the building blocks of cannabis: nitrogen, phosphorus, and potassium. You can find these components in worm castings, bone meal, and compost.
Step 3: Then, mix the soil. It’s as simple as that, and you’re on your way to having the best soil to grow marijuana.
Improving the soil, you already have
There are several minerals, soils, and nutrients that you can add to the soil you already have to make it suitable to grow excellent cannabis. Here are a few suggestions:
- Coco for cannabis: Coco-coir is a flexible growing medium made out of coconut shells that grants your plants the ability to grow even faster than they already are.
- Perlite: This can help loosen and provide excellent aeration to the soil and also aids in the speed of growth of the plant.
- Vermiculite: This is good for dampening the soil and raising the pH level of your cannabis.
- Worm castings: These are great for resolving nitrogen cannabis deficiencies. This nutrient-rich manure is perfect for any weed soil mix.
- Nutrients: Along with nitrogen, potassium, and phosphorus, marijuana soil also needs calcium, magnesium, copper, iron, and many others.
Before we move on to our FAQs: if you want to know more about growing, be sure to check out our marijuana for beginners guide. It offers a lot of helpful information about costs, climate, strains, and much more relating to growing marijuana.
FAQs related to best soil for cannabis
We’ve scoured the internet and put together the most frequently asked questions to help you find the best soil for growing weed.
What is the best soil for growing cannabis?
Loam is undoubtedly the best soil for growing cannabis. Its pH level is close to the ideal level of 6.0. Regrettably, it’s quite an expensive soil to buy but a worthwhile investment if you want to grow the best marijuana plants possible.
What is the best soil for outdoor cannabis?
Outdoor cannabis grows well with organic soil. You can make your own or opt to purchase a mix online or at a local garden store.
What is the best soil for indoor cannabis?
The ideal is the same as the best overall cannabis soil, which is loam. If you’re not willing to pay the price, though, you can always opt for a nice pre-packaged cannabis soil mix. Just make sure that it’s full of quality nutrients!
What is the best organic soil for cannabis?
You’ll want a soil mix that’s teaming with all the necessary micro and macronutrients needed for your plants. A nice blend of worm castings, rock dust, bone meal, bat guano, and various other soil amendments is the way to go.
What are the best nutrients for cannabis in soil?
The fundamentals are:
- Nitrogen (blood meal, ammonia, or cottonseed meal).
- Phosphate (bone meal, slag, and rock phosphate).
- Potassium (wood ashes or seaweeds).
It comes down to you
As you can see, there’s a lot to consider when choosing the best soil for growing marijuana. It depends on the type, where you’ll be growing it, and what you hope to achieve.
There are a lot of great ready-made products out there, both online and in-store. It just takes some time and research to figure out which is right for you.
Do you feel ready to start growing? Peruse the i49 website and decide on the right cannabis seeds for you to start your growing journey today.
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Best Soil For Growing Weed Indoors
If you have an indoor cannabis grow set-up, you need the best soil for growing weed indoors. Our cannabis soil guide dives deep into the factors to consider when shopping for soil for pot plants including its drainage, water retention, and texture.
In addition, we list our favorite potting soil products for cannabis, so you can grow big and bountiful yields time after time.
Choosing the Best Soil for Indoor Cannabis Gardens
When shopping for the best potting soil for cannabis, there are few factors to consider. First, how many plants are you intending to grow? This will help determine the amount of soil you will need.
Above all, you want soil with plenty of nutrients, proper drainage, and good water retention. Here are some factors to consider when buying the best potting soil for weed.
The best soil for growing weed indoors includes an optimum mixture of silt, sand, and clay soil, known as loamy soil. Ideally, the mix should have about 40% silt, 20% sand, and 40% clay.
Make sure your plants get a loose and light soil texture to help with root growth and ensure oxygen gets to your roots.
Cannabis potting soil requires proper soil drainage. When watered, the soil should not hold the water too much to where it pools on the top. If you have bad drainage, your plants can be vulnerable to root rot and mold.
While you want soil with proper drainage, you also don’t want the water to completely flush through without allowing the roots to take in water and nutrients.
Water retention refers to your soils ability to hold water. The best soil for growing pot indoors has balanced drainage and water retention properties.
PH refers to how alkaline or acidic solution is. Cannabis thrives in a soil pH range between 5.5 and 6.5. Deviating slightly from this range won’t cause too much damage but if it goes well beyond the range, you can get stunted growth, lower yields, and dead plants.
Nutrients are your cannabis plants life force. Most ready-to-use and organic soil mix for weed is packed with nutrients for your cannabis.
Keep in mind, the nutrients in your soil mix don’t last forever. At most, they can last a few weeks and require you to keep a close eye on any nutritional deficiencies or signs of overfeeding.
Best Soil for Growing Weed Indoors
1. FoxFarm Happy Frog Potting Soil
FoxFarm’s Happy Frog Potting Soil is ready-to-use for indoor and outdoor applications. Happy Frog potting soil features soil microbes such as mycorrhizae and humic acid to improve root growth and nutrient uptake.
Other goodies include bat guano, aged forest products, and earthworm castings. Keep in mind, this soil is designed for container planting.
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2. FoxFarm Ocean Forest Potting Soil
FoxFarm’s Ocean Forest Potting Soil features a robust blend of ingredients from the “earth and sea.” Its powerful ingredients include fish emulsion, aged forest products, earthworm castings, crab meal, and sphagnum peat moss.
Its sandy loam, aged forest products, and sphagnum peat moss give this soil a properly aerated texture that is sure to improve nutrient uptake. This soil is also designed for container use.
3. Super Soil Organic Concentrate
From Nature’s Living Soil, the Super Soil Original Organic Concentrate comes in a 1, 5, or 10 lb. bag. All you need to do is add your preferred organic potting media to complete your mix. It contains all organic ingredients that your plant will need to thrive.
Full of helpful microorganisms and fungi, this concentrate can produce the best-looking and tasting buds around. Ingredients include organic earthworm castings, bat guano, blood meal, bone meal, azomite, epsom salt, coconut water powder, kelp meal, alfalfa meal, and so much more.
4. FoxFarm Coco Loco Potting Mix
FoxFarm’s Bush Doctor Coco Loco is a coconut coir potting mix meant to recreate the tropical jungle floor. Light and airy, it does this by incorporating layers of exotic coconut palm humus which can hold more than its weight in water while still retaining great drainage characteristics.
Its ability to hold onto water will mean you wont need to water your garden as often. Water every few days for best results.
5. Big Rootz All-Purpose Potting Soil
Big Rootz’s All-Purpose Potting Soil features a professional-grade composition at a budget-friendly price. This cheap soil for growing weed is meant for indoors or outdoor gardens and has been Certified Green Clean (CGC).
A team of weed growers developed this high-quality formula that combines rapid-release amendments with medium and slow release for an optimal performance.
6. Roots Organics Rod Original Potting Soil
Roots Organics Original Potting Soil is ready-to-use for your indoor garden. Its formula is perfectly designed for aeration and water retention so you can feed your plants frequently for fast growth.
Plus, the soil bags can be used as pots. Simply cut off the top, add in your plant, and you’re set. Ingredients include coco fiber, perlite, peat moss, pumice, composted forest material, bat guano, worm castings, fish bone meal, and much more.
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Best Soil for an Outdoor Cannabis Garden
Correctly preparing the soil for an outdoor cannabis garden can make all the difference to the quality and size of your eventual harvest. Cannabis has specific requirements in terms of soil quality and texture. Here is a brief guide to ensuring all variables are optimized.
Choosing the best soil for cannabis means monitoring soil acidity, texture and pathogens or pests inherent in soil. Making your own soil or purchasing sterile soil gives you full control over the acidity, nutritional content and texture of the soil. At the same time, planting in the ground exposes cannabis plants to the entire living organism that is soil — and this is very difficult to create in a pot.
In any case, the growing medium is fundamental to the grow itself as well as the final harvest. Having well prepared soil can help a grower mitigate problems throughout the grow. Theoretically, if soil is well nourished, the plant should thrive with little intervention. A healthy plant necessarily starts with great soil, and without the optimum soil for growing cannabis, you will never be able to bring about an optimum harvest.
Soil texture and composition for outdoor soil
The best soil texture for cannabis is light, loamy soil that drain swell but also retains a degree of moisture. Loamy soils are a mixture of sand, silt and clay in an approximately 40:40:20 ratio:
- Sand is a major constituent of many soils, and is characterized by granular particles of rocks and minerals that measure 0.05mm to 2mm in diameter.
- Silt is finer than sand, and consists of particles measuring 0.002mm-0.05mm.
- Clay is finer still, and its particles measure less than 0.002mm in diameter.
One method of determining soil composition involves shaking soil in a jar full of water and allowing the particles to settle; a more detailed explanation can be found here.
The smaller the average particle size in soil, the harder it is for water to travel through it. You can think of it like a coffee machine. If you pack the coffee into the wand too tight, it’s near impossible for the water to come filtering through. By the same principle, sandy soils have very quick water drainage, while soils with high clay content become waterlogged easily.
If you’re using natural local soil, you can mix extra sand, silt or clay into it to improve its soil draining or retaining capabilities as needed. Drainage and soil stability may also be improved by adding gravel, which in technical terms is rock and mineral particles measuring 2m-75mm in diameter. Larger rocks can be removed where possible to avoid causing obstruction to the roots of plants.
If soil is poor, you may wish to consider buying good-quality commercial soil and mixing it into existing soil. You can also add manure, mulch, bloodmeal, bonemeal, or a range of other soil additives designed to improve nutrition release. You can even grow your plants entirely in bought commercial soil, in bags or pots so that they are not exposed to local soil.
Regulating pH of soil for growing outdoors
The optimum pH range for cannabis is between 5.5 and 6.5, making it slightly acidic. If soils are more acidic or alkaline than this, a range of deficiencies or toxicities can result. Soil that is too acidic or too alkaline disturbs a plant’s ability to absorb and use nutrients. If nutrients are not taken up in optimum ratios and quantities, your plants will not achieve the maximum quality and yield, your final harvest will suffer as a result.
Soil pH can be adjusted with a pH regulator. This is usually a solution that can be purchased from any gardening store. The most commonly used ingredient to lower pH (make it more acidic) is sulphur. Sulphur reacts with specialized bacteria commonly found in soil to create sulphuric acid, therefore acidifying the soil.
To increase pH, agricultural lime is usually added to soil. However, it isn’t necessary for cannabis cultivators to purchase sulphur or lime. These are usually available in solution at garden stores. A thorough guide to adjusting pH can be found here.
Remember that before you add a pH regulator to your soil, you first must know the current pH of your soil. This is measured with a soil pH meter. It can also be purchased from your garden store. You should only add pH regulator to your soil once you know the current state of acidity.
How to Choose the Best Outdoor Cannabis Strain
Sterilizing your outdoor soil
Sterilizing your soil by exposing it to steam can kill off many harmful bacteria, fungi and insects, while allowing several beneficial bacteria to remain alive. If purchasing good-quality commercial soil intended for growing cannabis, it is usually unnecessary to sterilize soil. However, if using local, natural soil, it may be helpful to sterilize where possible. It may also bring the added advantage of killing off any unwanted weed seeds present in the soil.
Sterilizing is a difficult and time-consuming process that is often overlooked though. If it’s not feasible to conduct this step, there are other ways to control pests. You can introduce beneficial microbes and insects to soil, as well as organic, plant-based compounds that repel or kill pests without harming the plant.
There are various techniques for sterilizing outdoor soil. Solarization is one method, and involves thoroughly tilling the soil so that it is broken up into fine pieces, watering and covering with a sheet of clear plastic.
The sheet of plastic amplifies the heat and light of the sun and allows the soil to reach high enough temperatures to kill off most undesirable microorganisms. Soil must reach temperatures of 46°C (114°F) for four to six weeks to be fully effective. It should be checked and re-tilled regularly to ensure that temperatures are sufficient and consistent.
If soil solarization is not possible due to time constraints, it may be possible to sterilize your soil by using steam. Large-scale agricultural operations make use of expensive, specialized equipment, but it is possible to use cheaper household sources of steam such as a pressure cooker to sterilize soil.
There are also methods that have been designed for smaller-scale grow operations. For example, the Hoddesdon grid method is a technique that involves layering tilled loam on a steel grid over a shallow pan of constantly-boiling water so that steam can rise through it. When temperatures reach 82-88°C (180-190°F) throughout the soil, sterilization is complete.
Growing outdoors: Pots, bags, or holes in the ground?
When growing outdoors, there are several options available: grow your plants in pots or planters, keep them in growing bags (which may be the plastic sack your commercial soil was purchased in, or may be specially-designed bags that are typically made of hessian or breathable plastic). You can also dig holes in the ground and plant directly into the soil. Outdoor soil can be optimized using the methods outlined above, or use without modification if testing shows it to be naturally optimized for growing cannabis.
If growing in pots or bags, you have the advantage of using commercially-bought soil which is not only optimized for growing cannabis but pre-sterilized to ensure that no harmful microbes are present. The downside is that your plants will be constricted by the size of their container. Pots may also require regular transplants as well as water (which they cannot receive from groundwater as plants in permeable bags or holes in the ground can).
On the other hand, digging holes in the ground and planting your young plants straight into the soil allows them to grow without constraint, and will allow roots to access the maximum amount of groundwater. Thus, they will achieve larger sizes and will require less vigilant maintenance, but may be at increased risk of exposure to soil pathogens and even contamination from agricultural run-off, for example.
Choosing the best soil for cannabis is often not as complicated as growers make it out to be. This is especially true for those who are just beginning to grow cannabis, and are not particularly concerned with yielding specific amounts of specific cannabinoids. Cannabis grows almost everywhere, and is known to grow in wet soil next to riverbeds as well as on rocky mountainsides. Well-nourished soil with the correct texture and pH is the best starting point, after which many adjustments can be made throughout the grow using nutrients and pH regulator.
Watch your plants throughout the grow, and adjust the soil as need be. Growing cannabis is a learning process that requires time and patience, and the best things are learned on the job!
Laws and regulations regarding cannabis cultivation differ from country to country. Sensi Seeds therefore strongly advises you to check your local laws and regulations. Do not act in conflict with the law.