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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.

Texture

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.

Drainage

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.

Water Retention

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

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

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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7. Mother Earth Coco Perlite Mix

Mother Earth Coco and Perlite Mix contains 70% cocoa and 30% perlite. It's a soil with an incredible porosity, texture, and high cation-exchange capacity.

As an alternative to traditional potting soil, coconut coir can provide improved aeration and drainage for your heavy feeding plants so that you don't have to worry about overwatering.

Become a Master Grower

Choosing the right type of soil can help your cannabis crop grow to new heights and produce a bountiful yield. Growing weed indoors has never been more affordable or accessible for growers of all skill levels.

Cannabis Training University can help you get your garden set up and guide you through every step of the way and beyond. From marijuana for beginners to our cannabis growing pro program CTU has something for everyone.

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