Soil or hydroponics? This is the fundamental question every indoor cannabis grower had to answer eventually before starting a new garden. Even though most marijuana growers use at least some hydroponic mediums in their soil grows today, there is still a significant difference between the two methods. However, soil-less mixes can amend soil growth ideally, allowing for better oxygen flow in the root system. Unless you are growing outdoors, it is unlikely that you will only use regular potting soil -and neither should you!
This article will examine the benefits and drawbacks of growing in soil-based mediums and how you can use hydro mediums to your advantage!
Pros and Cons of Growing Cannabis in Soil
There is no right or wrong way to grow cannabis. However, growing weed in soil has many advantages over a full-blown hydroponic grow (especially for beginners). The first and most obvious one is simplicity. There are no complicated hydro systems, no need to worry about nutrients all the time, and no need to change reservoir water every once in a while. Secondly, the budget savings you get with a simple soil grow are considerable. As we’ve seen before, hydroponic systems can be a sizeable investment that not all people can afford.
Also, plants grown in soil are easier to take care of, and mistakes are more reversible as side effects take more time to spread. Fertilization is more convenient because you can use your compost from everyday organic solid waste, like leaves, grass, food waste, fruit peels, coffee grounds, and manure (although I doubt you’d want to keep the latter around your apartment).
Cons of Growing in Soil Mediums
While there are considerable advantages in growing soil marijuana, it’s not all roses. Below you will find some of the most common problems with soil growing.
- Marijuana grows slower in soil than in hydroponic grows, as the nutrients and oxygen have to travel through the mulch to get to the roots. To address this, it might be a good idea to treat your soil with some hydroponic medium, such as perlite. This will ensure better oxygen and nutrient flow to the roots.
- Unless you are growing outdoors or in a shed/garage, you will have a hard time storing large bags of soil. It is messy and dirty, and that’s something you definitely don’t want around your living space.
- Pests and insects are other nuisances you should keep in mind. Soil-borne-intruders will try to invade your grow, and if you are not careful, attack your plants as well.
- Adding just the right amount of fertilizer might be tricky. Whether you go the organic way or not, stick to the instructions (and go even lower). It is hard to recover from the effects of over-fertilization and super easy to avoid them altogether! Try not to buy chemical nutrients. They may be cheaper, but they are not sustainable for your plants and the environment!
Overall, if you don’t have a green thumb, it might be wiser to go for a hydroponic grow. There are countless tutorials on the internet, and setting a system up and running isn’t even that hard! In any case, the soil grows are better suited to outdoor (or semi-outdoor) grows, as they can be messy and dirty.
Buying Soil For Cannabis
There are virtually endless types of soil available for purchase, either through Amazon or your local garden shop. Most of them come enriched with nutrients and microorganisms. Unless you are growing outdoors, refrain from using garden soil and stick with sterile potting mixes. The main properties that you want your soil to have are:
- Good drainage
- Water retention
- Suitable (light) texture
Most soils on the market come enriched with nutrients and other amendments. Don’t dwell too much on this, as pretty much anything will do. The important things are the ones we mentioned above.
However, if you are the meticulous type, a good soil mixture for marijuana would look dark in color and soft to the touch! Concerning ingredients, look for a soil mix that contains some of the following:
- Earthworm castings
- Bat guano
- Peat Moss
- Coco coir
- Bone Meal
- Fish meal
- Glacier rock dust
- Plant food
- Forest humus
- Blood meal
All of the above soil amendments are great for cannabis grows. Both will be perfect for your grow, as long as the texture, drainage, and water retention are right.
Super Soil: A Self-Sustained Environment
What’s even better than organic nutrients, especially for bringing up the taste of your strain, is to grow your marijuana in “super soil”. This type of soil (also called “living soil”) is enriched with living colonies of beneficial microorganisms like bacteria, actinobacteria, fungi, protozoa, and rotifers. A whole micro-world in your soil, working for your plant!
You can create this mixture by mixing good-quality soil with compost. From there on, the bacteria will do all the hard work for you, automatically regulating the pH and providing the soil with nutrients. Evidence suggests that marijuana grown in such a medium tends to be considerably more flavorful and fragrant. Generally, soil-grown weed tends to be better in terms of taste.
Why Use Super Soil
Arguably, the most important part of growing cannabis in soil is the mixture that you will use. As we’ve already seen, nutrient makeup, water absorbance, and pH levels are all things to consider when getting potting soil for your marijuana garden. Therefore, you must buy or create the ideal blend.
While you can always go for normal potting soil and skip this step, living or super soil is the perfect supplement for your grow.
- It is organic and will make your plants feel “right at home”
- It promotes a more complex terpene profile, enhancing bud taste and smell
- There is no need to flush it before harvest, as you’d normally do in any other grow
- The whole process of pH maintenance and nutrients is automated by the microorganisms living in the soil!
Bear in mind that you will have to mix the super soil with a growing medium of your choice or normal potting soil. Consult the manufacturer for more in-depth instructions. Also, bear in mind that young seedlings might not be able to handle super soil. Start off the baby plant in regular soil and transplant it to the amended mixture when it has developed a solid root system.
TIP: Asking the experts is always a good idea. Visit your local botanical garden or supply store and ask around about the best soil mixture for cannabis (or, tomatoes as their needs are similar).
Super Soil Maintenance
There is a saying for marijuana growers that goes like: feed the soil, not the plant. And there is a lot of truth behind those words. Remember, super soil is also called living soil. And, as a living entity, it needs help so survive and take care of your plants. It’s the circle of life! So, let’s take a look at how you can maintain, amend and feed your super soil so it will keep on giving!
Time for (Compost) Tea
If you are growing indoors, chances are that you lack the space to make your own compost. Compost teas, however, can easily be brewed at home and kept in a bottle. Supplementing your super soil with an energy boost every two weeks or so is good, although there is no definite answer. You can use it directly on the soil or spray it on the leaves. Either way, it is a natural and efficient way to rejuvenate your garden!
In the simplest words possible, mulch is a layer of organic (or other) material spread over the topsoil of your plant. This layer can be anything from leaves, tree bark, newspapers to rubber tires and special material. There is a comprehensive list of stuff you can use as mulch here. Just cover the topsoil with a layer from 1 to 5 inches of fresh mulch and renew every month.
Mulch has a host of benefits for your soil:
- It protects the soil from extreme weather
- It enriches the colonies of fungi and bacteria
- It keeps the soil moist at all times
- It protects the root system
Add Mycorrhizae (mycorrhizal inoculant)
In Greek, mycorrhiza translates quite literally to fungus-root (mykes+rhiza). These symbiotic organisms maintain a mutually beneficial lifeline with your plants. In a mycorrhizal association, fungi make the root tissues of a plant their home. In return, they help the plants break down the nutrients that the plants need and protect their roots.
Supplementing your garden with mycorrhizae is easy and very beneficial in the long run. Ask your local garden shop, and they will give you more information about what to buy. Add the inoculant as early as possible and be sure to spread it out across the entire root zone. The rest is nature’s job!
Setting Up A Marijuana Soil Garden
Assuming you’ll be growing in aerated super soil (which you should), things should be pretty easy in setting up your garden. You can find some helpful guidelines for building your grow area here. However, feel free to improvise and adapt where you see fit. There are countless ways to grow marijuana, as long as you provide it with a few basic commodities.
Apart from your very own “house recipe” some of the best pre-made cannabis soil mixes include brands like:
- Royal Gold
- Fox Farms
- Roots Organic
In soil, you can use pretty much any container you’d like. The material doesn’t matter as much as the volume of the container. If you have the right soil, most of your time will be spent watering your plant. In any case, you must always keep a pH meter in your list of growing supplies and frequently check for imbalances. Although super soil is pretty much self-contained, it’s not a hands-off growing method!
It goes without saying that you should throw away the soil after each plant completes a life cycle. Most of the nutrients will be used up, so growing a new plant, although possible, won’t be worth the cost.
Speaking of costs, depending on the grow light you are using, be sure to prepare for the worst: Keep some replacement bulbs in-store and be sure to avoid overwatering. In soil grows, this is the root of many problems. The weight of the growing medium multiplies with water and can drown the roots. Only water when the top soil feels dry to the touch. Naturally, a plant will use up more water if the temperature around it is above average, so keep that in mind.
Containers: Size Matters!
The pot in which you’ll grow your pot needs to be at least a gallon (3 liters) for a small marijuana strain or a seedling. Anything larger than 40cm in height should be moved in a 2-gallon container and so on. Plants that grow over 80cm high need at least 5-gallon containers to develop an adequate root system.
As tempting as it sounds, avoid sticking a germinated seed directly in the final container. The sheer weight of the soil can crush the vulnerable root system of the seedling. Instead, move it gradually from one container to the next until it has developed a relatively strong taproot. This will promote development and yields in the long run.
Soil Or Hydro?
To be blunt, this dilemma has long been obsolete. Eventually, you will end up using some hydro-growing mediums in your soil (but not vice versa). Long story short, go for soil if:
- You are growing outdoors;
- You don’t mind getting your hands dirty;
- Waiting a little bit more for harvest doesn’t bother you;
- Taste in your cannabis is more important than quantity.