soil ratio for growing weed

The optimal ratio for loam is 20% clay, 40% silt and 40% sand. Most folks think a pH of 6.0 is best for cannabis, with a range of 5.8 to 6.3 being acceptable. With a pH close to neutral, loam is typically in that zone or close to it.

In addition, you do not necessarily have to provide costly soil for your plants outside. But for the best results, you want good marijuana soil that will help your plants grow healthy and happy. DripWorks is here to offer you a few simple tips for finding and creating the best soil for growing marijuana outdoors.

Silt soils have lots of minerals and retain moisture well. Like clay, however, this type of soil can become compacted and hard in certain conditions. It can also form a crust, making it difficult for moisture and nutrients to reach plants’ roots.

Loam for Growing Marijuana & Other Crops

Test kits are available to measure your soil’s acidity, or you can take a sample to your friendly local extension agent. If your dirt does not have the proper acidity, soil amendments are available to lower or raise the pH level in your soil. Your local nursery, garden store or extension agent can make some suggestions.

Loam is ideal for containers as well as for outdoor growing. Unfortunately, it is usually the most expensive soil to buy. But if you are interested in growing the best plants possible, it can pay big dividends in the long run.
You can also build up your own loam soil by adding organic matter to it. If you have a compost bin, you can use the compost to improve your soil. This will be a time-consuming and ongoing process but with grit and persistence will pay off in the long run.

Soil Types

Clay is just the opposite. When it’s hot and dry, clay can become hard as a rock, making it difficult for roots to penetrate. Clay drains poorly and is hard to cultivate. On the plus side, it is rich in minerals and natural nutrients.

Growing cannabis outdoors offers many benefits. Firstly, it can be very affordable. You do not need to provide a structure like a greenhouse or high tunnel. In addition, artificial light is not necessary if you place it in the right spot in your yard, because your plants can benefit from the sun’s abundant and free energy.

Soil ratio for growing weed

However, when growing with Super Soil, it’s a good idea to avoid watering too much at a time, as extra runoff waterwill drain away some of the nutrinets. Try to give just enough water to saturate the soil with very little extra coming out the bottom. Since you won’t be adding more nutrients through the grow, you want to conserve what’s in the soil!

In order for a cannabis plant to grow and thrive, it needs a good mix of both water and oxygen at the roots at all times! Too much water and the plant roots can’t get enough oxygen (lack of oxygen at the roots is why plants get droopy from overwatering) but on the flip side if there’s not enough water retention the roots can be injured from drying out too quickly!

Some growers choose an amended and composted “hot” soil that slowly releases nutrients over time. With this type of soil, you typically just add water or natural supplements like worm tea from seed to harvest. Other growers prefer a lighter potting mix so they have more control, and give nutrients in the water once the plant roots have used up the nutrients in the soil. But which brands can you trust?

It’s easy to get caught up thinking about what nutrients and amendments are in the soil, and those are important, but perhaps the most important aspect of any soil is actually its texture, ability to drain, and overall water “holding” ability.

Kind “Super” Soil (Living Soil)


(picture by Wattze)

Fox Farm has been around for over 30 years and makes some of the most common types of “cannabis soil” (at least in the US). They have several great soil mixes, including “Happy Frog” which is a great choice for seedlings and clones.

Usually an organic potting mix does not have enough nutrients to last your plants for more than a few weeks, so it’s a good idea to always supplement with cannabis-friendly nutrients, especially in the flowering stage when your plant is making buds and needs lots of extra Phosphorus and Potassium.

Texture, Drainage & Water Retention

Recommended soil nutrients:

What gets the best results for growing cannabis is a soil with a light texture that is good at retaining water…but not too much!

Soil ratio for growing weed

However, building your own soil at home can be just as easy, cost-effective, and accessible as buying a pre-mixed bag at the store. Creating your own super soil will also teach you a lot about soil science and how the components of soil will effect the outcome of your cannabis grow.

What is an organic super soil?

Phosphorus-rich nutrients

Step 2: Find the right soil amendments

Fungi love to develop mycorrhizal relationships with root systems (the rhizosphere), and providing food for them to thrive will help facilitate these tiny symbiotic relationships.