best soil mix for growing cannabis outdoors

Designed for indoor and outdoor cultivation, Happy Frog potting soil takes care of young cannabis plants’ essential needs, from correct pH levels to balanced nutrients, including a vital combination of microbes and fungi from earthworm castings and forest humus.

From planting seeds to harvesting buds, Nature’s Living Soil’s Organic Super Soil has you covered through cannabis’ entire grow cycle. Reviewers love the ready-to-use simplicity this soil provides: just plant, water and wait. For those growing on their own for the first time, this is one of the best soils you can buy.

Fox Farm’s specialized line of soils for cannabis are some of the most widely acclaimed grow mediums available. If you’re beginning your grow journey from the ground up, Happy Frog is an excellent soil to nurture seeds and seedlings.

Fox Farm’s Happy Frog Potting Soil.

The best soils for weed don’t always have to be products specialized for cultivating cannabis. Sometimes, a good organic potting soil is all you need, and Sungro’s Black Gold all-organic potting soil is an excellent case in point.

If you’re planning on planting a large container cannabis garden outdoors, Roots Organics Formula 707 is a versatile and capable option. An organic soil designed with greater water-holding capacity, Formula 707 contains ingredients and beneficial microbes specific to using larger containers.

Cannabis plants spring up like a literal weed. But growing weed optimally — in a way that allows it to express its best traits and produce trichome-rich flowers — demands care, attention to detail and a bit of trial-and-error. At the same time, there’s no better way to develop a closer, more connected and more rewarding relationship with cannabis than growing some yourself. To get you started, here’s our list of the five best soils for healthy weed.

If you’re digging through the literature on growing weed, you’ve probably seen the term “super soil” come up quite a bit. Coined by the legendary grower and seed producer Subcool, the term generally describes a neutral organic soil base that’s been enhanced with a comprehensive range of “amendments,” i.e., added nutrients and microorganisms. Using a super soil eliminates the need for liquid nutrients as your cannabis plants grow.

Still, Formula 707 has enough nutrients to last 10-14 days before you need to add anything. And for convenience, you can use the soil bag itself as a pot. Just cut off the top, poke some holes in the bottom, plant your seedlings and you’re ready to grow.

Your soil’s nutrients and the water you provide need to link up to be available for and absorbed by plants’ roots. Biochar, a carbon-rich charcoal amendment, not only facilitates this process but it also provides a large surface area for microorganisms to live and thrive. Red’s Premium Biochar-based soil thus creates an ideal “habitat” for all the living beings that help your cannabis plants reach their full potential.

Nature’s Living Soil Organic Super Soil.

But just as important as what’s in this soil is what’s not: less perlite, less pumice, and fewer amendments. This makes Formula 707 a highly customizable soil, allowing you to add your topsoil and liquid nutrients at various growth stages depending on your cannabis plants’ needs.

At a price point that won’t put a hole in your pocket, Black Gold boasts all of the essential traits of a strong soil for growing weed. Its loamy mixture contains an optimal blend of pumice and perlite for hydration and microorganism development, and its balanced nutrient blend won’t burn young cannabis plants. Those features have won this soil praise from gardeners of all stripes, cannabis growers included.

Red’s Premium is another all-in-one, ready-to-use soil blend. But what makes it one of the best soils for weed is its stand-out feature: biochar. Biochar is an amendment that excels at protecting and promoting the growth of bacteria, fungi and other microorganisms that are essential for root development and strengthening your plant’s immune system.

If growing cannabis is an art, then the soil is the canvas, paint and even a little bit of the brush. As your “grow medium” (the material that your plants grow in), the balance of nutrients your soil contains shapes how your plants grow, how fast and abundantly they flower and how many buds they yield.

Red’s Premium Biochar-Based Soil.

Every ingredient in Black Gold is organic, and it’s suitable for a wide range of environments, from patio containers to indoor hanging baskets. The bottom line: Black Gold is a reliable and high-performance base soil for cannabis. You can also get hands-on with this soil, since adding amendments as your plants grow is super easy.

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.

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.

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.

Soil texture and composition for outdoor soil.

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.

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.

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.

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.

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.

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.

How to Choose the Best Outdoor Cannabis Strain.

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:

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).

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.

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.

Sterilizing your outdoor soil.

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.

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.

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 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.

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.

You may need to put all of your plants in containers if you don’t have great soil. Also, if you’re unable to perform the heavy labor needed to dig holes and amend soil, containers may be the only way for you to grow your own cannabis outdoors.

Big yields.

If you’re growing weed outdoors, it’s great to find a community of cannabis growers in your area to see how others are growing in your specific climate. Local climates vary, so it can be helpful to see what strains thrive where you are, and also when other growers are popping seeds, harvesting, and more. You can also join online forums or Social media groups, but a great place to start is your local grow shop.

In general, 5-gallon pots are a good size for small-to-medium outdoor plants, and 10-gallon pots or larger are recommended for big plants. Regardless of size, you’ll want to protect the roots of your plants from overheating during warm weather, as pots can quickly get hot in direct sunlight. This will severely limit the growth of your plants, so be sure to shade your containers when the sun is high in the sky.

However, plants grown in pots, buckets, or barrels will likely be smaller than those planted in the ground because their root growth is restricted to the size of the container. In a broad sense, the size of the pot will determine the size of the plant, although it’s possible to grow large plants in small containers if proper techniques are used.

Loam soils.

Your cannabis plants should receive as much direct sunlight as possible, ideally during midday, when the quality of light is best. As the season changes and fall approaches, your plants will get less and less sunlight throughout the day, which will trigger the flowering stage.

Once you have an understanding of the climate in your area, you’ll need to consider a few things before planting your weed.

Weed plants will need full, direct sun for at least 6 hours a day. You may have a backyard, but it might not be great to grow there if it doesn’t get full sun every day.

Some growers plant in containers on balconies or rooftops that are shielded from view, while some build heavy-gauge wire cages to keep thieves and animals at bay. Whatever you decide, think about how big you want your final plant to be—outdoor cannabis plants can grow to 10 feet tall or even more, depending on how much you let them go.

Start off with fertilizers that are inexpensive and readily available. Some release nutrients quickly and are easily used by the plant, while others take weeks or months to release usable nutrients. If done correctly, you can mix in a few of these products with your soil amendments to provide enough nutrients for the entire life of your plants. Most of these items can be purchased cheaply at your local nursery.

Soil, at a basic level, is defined as the topmost layer of earth in which plants grow—it’s a mixture of organic remains, clay, and rock particles. Cannabis plants thrive in soil rich with organic matter, and they need good drainage.

While some plants thrive in their native soils, which are usually one of the compositions listed above, cannabis plants are best grown in soil that includes a combination of the three consistencies above—this mixture is known as loam.

Growing marijuana outdoors is great because you won’t need to spend a ton of money on it and you can rely on the power of the sun. If you have access to a sunny spot in a private yard or even a balcony, terrace, or rooftop, you can grow weed outside. You will be tied to the sun and the seasons and local weather, but you won’t have to spend a bunch of money on equipment and utilities like indoor growers.

Roof: This can be great for sun but may have too much wind.

It’s fun and relaxing.

How to set up your outdoor marijuana grow.

The sky’s the limit with outdoor plants—you can let them get as big and tall as you want, as long as they’re manageable. One plant can potentially yield between a half-pound and full-pound of dried weed! Growing a handful of hands for yourself is more than enough. With an indoor grow, your space is a lot more restricted.

While shopping for soil, you might be overwhelmed by the options available at your local garden store. The soil type is the basic structure of your soil. From there, look at nutrients, microorganisms, and other amendments that improve the soil. Your choices will be flooded with words like:

Low costs.

Heavy rains and high winds can cause physical damage to plants and reduce yields, and excessive moisture can lead to mold and powdery mildew, especially during the flowering stage.

Environmentally friendly.

Heavy clay soils drain slowly and don’t hold oxygen well, so they will need to be heavily amended. A few weeks before you plant, dig large holes where you’ll be placing your weed plants and mix in big amounts of compost, manure, worm castings, or other decomposed organic matter. This will provide aeration and drainage, as well as nutrients for the plants.

Typically, outdoor growers will add amendments to soil when weed plants are transplanted outside. Outdoor amendments usually come in powder form that you mix in with soil.

Benefits of growing weed outdoors.

Most outdoor weed growers will either dig a hole and add fresh soil for the plant, or grow their weed in pots. This will allow you to better control the growing medium and the amount of nutrients your plants receive.

If you don’t have a suitable patch of earth to make a garden, containers can be placed on decks, patios, rooftops, and many other spots. If needed, you can move them around during the day to take advantage of the sun or to shield them from excessive heat or wind.

Silty soil is the ideal growing medium. It’s easy to work, warms quickly, holds moisture, has good drainage, and contains a lot of nutrients. The best silty soil is dark, crumbly loam—it’s fertile and probably won’t need any amending.

Cannabis plants require a large amount of nutrients over their life cycle, mainly in the form of nitrogen, phosphorus, and potassium. How much you need to add to your plants will depend on the composition of your soil.

We recommend these organic fertilizers:

These are just some examples of amendments commonly used in different types of soils. Heavily amended soils will have long lists that break down all organic nutrients they contain. Some companies create soils that offer a great structure with base nutrients, but allow you to fill in the gaps as you desire.

Don’t underestimate the therapeutic value of gardening. It’s relaxing to spend some time outside, roll up your sleeves, and get your hands dirty for a while. And there’s nothing better than smoking something you grew yourself.

For most first-time gardeners, we recommend buying a quality potting soil that will provide your plants with enough nutrients to get them through most of their growth cycle without having to add many amendments. This pre-fertilized soil—often referred to as “super-soil”—that can grow cannabis plants from start to finish without any added nutrients if used correctly.