Best Marijuana Growing Soil 

There are a lot of factors to consider when it comes to choosing the best marijuana growing soil. It’s important to make the right choice because it determines how well your marijuana will do once it’s planted. 

Even if you live in a great area, buy good seeds, and take care of your plants, you won’t get the best results if the soil isn’t suitable. The trouble is, getting hold of soil isn’t always easy. Plus, you’ll often see articles about making your own soil, which can only add to the confusion you might be feeling. 

The good news is that you’re right where you need to be. We’ll be clearing up all the uncertainty in this article by guiding you through the process of choosing the best soil for growing marijuana. 

The sections we’ve included cover topics like: 

  • The best soil for growing marijuana indoors 
  • The best soil for growing marijuana outdoors 
  • What type of soil is best for growing marijuana 
  • Boosting soil quality 
  • Comparing good soil and bad soil 

Once you’ve read through the article, you’ll know everything you need to get started with shopping for superb soil. When you’ve got your soil, you’ll have taken a big step forward in growing marijuana. 

When you’re searching for the best marijuana growing soil, it’s crucial to keep in mind that different strains of cannabis are best suited to different kinds of soil. That means you’ll have to do your research when you’re picking a strain. 

You’ll also have to factor in the climate where you live and whether you’re growing marijuana indoors or outdoors. Once you’ve got the details on all of this, you can begin to look at the soil itself. You’ll want the soil to have a range of traits, and we’ll take you through all of them in this section. 

Marijuana Soil ProductOur RatingPurchase
FoxFarm FX14054 Happy Frog Potting Soil, 12 Quart5/5PURCHASE SOIL
Fox Farm Ocean Forest 6.3-6.8 PH Plant Garden Potting Soil Mix, 40 Pounds-1.5 Cubic Feet (2 Pack)4.8/5PURCHASE SOIL
Big Rootz All Purpose Potting Soil pH Adjusted and Enriched to Maximize Root Growth4.6/5PURCHASE SOIL
Organic Super Soil Concentrated Strength4.6/5PURCHASE SOIL
Super Soil Autoflower Concentrate4.4/5PURCHASE SOIL
Purple Cow IndiCanja 1 Cubic Foot Bag Organic Living Soil4/5PURCHASE SOIL
Brut Super Soil – 30lb – Rich, Dark Natural Blend of Soil, Organic Matter and Worm Castings. Use Indoors or Outdoors. Non-Toxic and Odor Free.4/5PURCHASE SOIL
Mother Earth Terracraft Potting Soil, All Purpose Potting Soil For All Plants, Flowers, Vegetables And Tomatoes, 12 Quart3.8/5PURCHASE SOIL
FoxFarms 733266 Soil, Strawberry Fields Potting, 1.5 cu3.5/5PURCHASE SOIL

Important Soil Traits

The Soil Texture 

When you’re planting your marijuana seeds, they’ll want to experience soil that’s appropriately textured. That means loose and light soil. It has to have this texture because the roots will develop better and can absorb more oxygen. You should examine the soil you want to buy to see whether it has these qualities, as it’s essential for your cannabis plants to get enough oxygen. 

The Soil Drainage 

When you’re watering the best marijuana growing soil, it won’t retain excess amounts of water and will instead allow the water to pass through. That way, more of it can be taken up by the roots of your plants. You can discover whether the soil you want to buy has good drainage by pouring some water onto it. If it remains mainly on the surface, it won’t drain well. 

The Soil Water Retention 

Alongside good drainage, the best type of soil for growing marijuana should also retain water. That means instead of it running through very quickly, the water should gradually percolate through the soil. The ability of the soil to retain water and its ability to drain water should be well-balanced so that there isn’t too much drainage or too much retention. 

The pH Value 

The best soil for growing marijuana also needs to have a decent pH level. It will fall somewhere between acidic and alkaline no matter what soil you get, but the average for growing weed should be 5.8-6.3. If the pH moves too far outside of this range, your weed will not grow and could even die. 

The Nutrients 

The best type of soil for growing marijuana will be more than just soil. It will also contain a range of beneficial nutrients that help your weed to thrive. However, there is only enough in the soil for a few weeks. After that, you’ll need to replace them with added nutrients that you buy online or in stores. 

If you choose a soil type that doesn’t have nutrients in it, then you’ll need to add a range of other nutrients. We’ll discuss more about those later on. 

What Type of Soil is Best for Growing Marijuana? 

marijuana soil
Cannabis Soil & Marijuana Plant Seedling

Now that we’ve covered the traits that different types of soil can have, it’s important that we look at what those types of soil actually are. We’ll discuss them below. 

Sandy Soil 

This type of soil is good at draining water and is also quite coarse. Unfortunately, the water retention is poor, which means any water you put into the soil will rush past the roots. The same is true of nutrients. But if you’re looking for an easy way to start growing cannabis, sandy soil is acceptable. It has a low pH and good oxygen levels, which help balance out some negatives. 

Silty Soil 

Silty soil is less coarse than sandy soil, plus it has a lot of nutrients embedded within it. It also retains decent amounts of water, and has adequate drainage too. Like sandy soil, silty soil is quite simple for beginner growers to get used to. Because of the added nutrients, it’s also fertile. Your weed will be well-nourished in this type of soil. 

Loamy Soil 

Loamy soil is actually a combination of three different soil types. It combines clay, sand, and silt. It’s a great soil type if you can get hold of it because it has added nutrients and has suitable water retention and drainage. However, it does come at a cost. The price of loamy soil is typically higher, so if you’re on a budget, it could be unaffordable for you. 

Clay Soil 

Clay soil is a finer type of soil with smaller particles. It’s quite heavy compared to other soil types and can be challenging if you’re a beginner. It’s also not as good as the other soil types when it comes to drainage, so we don’t recommend it unless you know what you’re doing. However, it does contain a decent range of nutrients. 

Best Soil for Growing Marijuana Indoors

When you’re looking for the best soil for growing marijuana indoors, you’ll also want to have more control over your marijuana. It will be in containers, and you can decide how much soil you want to use. You’ll also be able to control the climate, nutrients, water, and any other factors. 

That means the soil you use isn’t as decisive as it can be outdoors. You can take your pick from any of the types discussed above and even test different soil types in different containers. Eventually, you’ll find what gets you the best results. Then you can simply stockpile that type of soil so you can use it for more cannabis plants. 

Best Soil for Growing Marijuana Outdoors

When you’re growing cannabis outdoors, the situation is a little different. It can get very hot without you being able to do anything about it. So the best soil for growing marijuana indoors is a type that has high water retention. That way, you don’t have to stop and water your weed plants so often. 

Silty soil would make a good choice for outdoor growing, especially if you’re growing cannabis outdoors. But you could also go with loamy soil if you have the money to afford it. 

How to Boost the Soil Quality 

top soil for marijuana grows
Digging in Soil to Plant Marijuana

If you’ve already got the best soil for growing marijuana that you can find, then you’ve already done a lot of the hard work when it comes to soil. But there is an extra step you can take, particularly if the soil doesn’t have many nutrients. 

You can add amendments to the soil, which improve its quality. There is a selection of amendments, and we’ll cover several of them here. 

Perlite 

Perlite is a common addition to soil, and most growers will know about it. It’s a type of rock that’s bright and white. Its main effect on the soil is to improve its ability to drain water and increase the oxygen levels in the soil. 10% of your soil should contain perlite, but adding more can make the soil too light. 

Vermiculite 

Vermiculite is another type of stone that’s similar to perlite but has a few key differences. Instead of aiding water drainage, vermiculite aids water retention. It doesn’t have a significant effect on oxygen levels, but it does make the soil lighter. Adding around 10% is a good amount. 

Clay Pebbles 

An alternative to vermiculite and perlite is the use of pebbles. You can structure your soil by using them. It will make your soil better at draining water while preventing it from remaining near the base of the soil, which can cause root rot if you’re not careful. 

Clay pebbles can also be added as a layer on top of the soil to retain moisture and prevent evaporation while ensuring that helpful microbes in the soil aren’t damaged by the sun. 

Worm Castings 

A somewhat unusual choice to add to your soil, but one that’s worth it, are worm castings. They have numerous benefits, like improving soil texture, water retention, and drainage. Because these are smaller and easy to crush, you should consider having a quarter of your soil made up of them. 

Coco Coir 

One final amendment that you can add to your soil is coco coir. It’s derived from coconuts and has two main effects. It will help your soil retain its quality, and it will make the soil lighter. You should have 30% of your soil as coco coir, but that amount can vary depending on your soil type. 

Good Soil vs Bad Soil

Now that you’ve learned some information about the best marijuana growing soil, it’s time to look at how to tell the difference between good and bad soil. We’ll list out what to look for. 

Good Marijuana Soil 

The best soil for growing marijuana will have a rich composition and be light. Ideally, it will have been put through a composting process, and you’ll have a decent batch of soil ready to use. 

Good soil will also have good drainage and be packed with nutrients. That means if you buy soil from a store, you should check it’s enriched and see what people say online about how well it drains water. 

As we covered above, good soil can be made even better with added nutrients like perlite. Some soils come with the nutrients added, so you should look out for that. 

Bad Marijuana Soil 

Bad soil tends to be easy to spot once you know what you’re looking for. You’ll discover that it’s full of water and sticks together. It doesn’t drain well, and your plants end up becoming saturated with water. 

It also tends to have many wood chippings and other debris mixed in, which aren’t healthy for your plants and reduce the soil’s benefits. Your plants won’t be able to make use of those parts of the soil. 

Soil that’s thick and heavy is bad too because it can slow down the growth of your plants and make them seem stunted and small. If you’re tempted to use soil that’s taken from the ground outdoors, then it’s also likely to be full of debris. 

Other Factors to Consider

Cannabis seeds
Cannabis seeds

Two additional areas are relevant when you’re picking the best type of soil for growing marijuana. These are the type of seeds you’re using and where you’re getting those seeds from. 

Type of Marijuana Seeds 

There are two main types of cannabis seed, and these are autoflowering and photoperiod. Autoflowering seeds are pretty self-explanatory. They will flower regardless of their situation and typically require a lot less maintenance than photoperiod seeds. 

If your seeds are autoflowering, you should mix light soil and coco coir, plus a little perlite. That will optimize your soil for autoflowering seeds. If you’re growing photoperiod marijuana, you should begin with soil that doesn’t have added nutrients and keep the seeds in small pots. You can add the nutrients once you’ve replanted the seeds after a few weeks.

Where You Buy Your Cannabis Seeds 

There are three options that you’ll have when it comes to getting marijuana seeds. You can visit a physical store, use seeds from plants you’ve already grown, or buy marijuana seeds online. We’ll take more about the latter in the final section. 

For now, if you’re getting soil from a store, then you’ll benefit from the experience of the people who work there. That way, you can guarantee you’ll get the best soil for growing marijuana. If you’re getting seeds from your plants, that’s very cost-effective, but you won’t know how good the seeds are until you use them. 

Marijuana Soil Tips

We also thought we’d include a selection of tips to keep in mind when you’re picking soil to use for growing marijuana. There are probably more online tips, but we narrowed them down to a few we thought were the most helpful. 

  • Feel the soil yourself – there is no better way to test soil consistency than sifting through it with your hands. 
  • Inspect the soil visually – it should appear rich and dark because pale soil or soil that crumbles is insufficient. 
  • Check the ingredients – a range of beneficial ingredients should be included, like bat guano, bone meal, and mycorrhizae. 
  • Avoid time-release nutrients – these can release excess nitrogen and kill your plants. 
  • Weigh the soil with your hands – if it seems too heavy and clumpy, it won’t be airy enough. 

Conclusion

Now that you’ve learned all about soil types and what type of soil is best for growing marijuana, you should be confident when it comes to planting your seeds. There is additional information available online if you need it, but you should be able to use this article to figure out what kind of soil you need and how to ensure it’s the best for your marijuana plants.

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