One of the simplest and easiest ways to save money when growing cannabis is using and recycling your organic soil. This is a much easier process than some growers might realize. Buying expensive soils can start to add up very quickly, when they cost $40 or more per bag and you need 3 or 4 bags for every single grow. In this article we will teach growers how to find the right organic soils, amend them with the proper long term nutrients, short term nutrients and how to amend the soil for long term reuse.
Starting With the Correct Organic Cannabis Soil Is Paramount
Any cannabis grower knows how important it is to select the right soil to start growing with. Cannabis prefers slightly acidic soils around 6.2 to 6.5 on the PH Scale. If the grower starts with poor quality soils, they will most likely run into many problems during the cannabis growing cycles.
For the best result look for soils that are 100% organic when starting out. They should also be free of any synthetic nutrients, and only contain organic nutrients and amendments. This will give you a good starting base for the best reusable soils. Even better if you are able to find a soil that is OMRI listed as organic soils.
If the grower doesn’t use a good soil from the start it can have issues, such as large PH fluctuations, this can cause nutrient lockout in your soils. Once the lockout happens the cannabis plants will not be able to take up any nutrients due to PH imbalance in the soil. This comes with an even greater risk when reusing soil.
Also any added nutrients to the soils can cause issues down the road with your reused cannabis soils. This can cause issues where your plants are having too high amounts of one nutrient, and deficiencies with another nutrient in your soil. This can cause poor plant growth, and unhealthy plants in the garden.
How to Amend Your Organic Cannabis Soils
Amending cannabis soils for the first time, needs to be completely correct to get organic cannabis soil that can be used for years to come. You will need to add both nutrients that will break down quickly for your plants to use, as well as organic nutrients that break down much slower providing your plants will have small long term amounts of organic cannabis fertilizers.
To get these best results we recommend that you use a nice mix of organic nutrients to your soil. Some growers refer to this as creating a “super soil” for their cannabis plants.



What to use for Cannabis Organic Amendments
While these are not everything that you can use, these are some great starter amendments. Adding these things to your soil for the first time will help you get started making reusable cannabis soils. Some growers like to make their soils, then let them sit for a few weeks to allow for some of the nutrients to break down a bit before using the soil in their containers. Cannabis needs most plant nutrients then most other plants so this would help to give them a quick growing start.
If you would like to learn more about growing cannabis organically we recommend reading this article. It is important to also top dress your cannabis plants, to get the best results reusing your organic cannabis soil. This will mean adding some of these amendments below to the tops of your soil, either in pots or outdoors.



Here are the amendments that we recommend starting your reusable soil with
- Blood Meal – Blood meal is a great quick release nitrogen source for your growing cannabis plants. Mix this in with the organic soil for lots of nitrogen for a few months of vegetative cannabis growth. After the initial release of nitrogen into the soil, it will also continue to break down releasing a slower amount of nitrogen to feed your cannabis.
- Ground Egg Shells or Seashells – The perfect source of calcium that can be added to the soil, either of these will break down slowly providing a nice slow consistent supply of calcium for your cannabis plants. Calcium in your soil is essential to growing microbiology in your soil over time and for your plants to use for strong healthy growth. Cannabis doesn’t need calcium in large amounts as it is only a micronutrient, so a nice slow source works every well like this one.
- Greensand – Another great amendment for your reusable cannabis soil, greensand has lots of slow release potash and contains iron, silica, and up to 30 other trace minerals for cannabis growing. As greensand can take up to 12 to 14 months to start to break down and be bioavailable to your plants we never recommend it for single use cannabis soils. However it makes a great amendment to soils that will be used for years and will break down during this time.
- Langbeinite – This high potassium amendment is great for reusable cannabis soils, it has a natural sulfur, magnesium and very high amounts of potassium. Adding this when creating your new reusable soil will allow for the langbeinite to break down just in time for the plant to start using in greater amounts for the cannabis flowering cycle.
- Alfalfa Meal or Dried Grass Timings – Another great additive to your soil mix is alfalfa, this is another great slow release nitrogen source for your reusable organic cannabis soil. This dried clover will break down adding nitrogen for your plant for years of use. It is also a much slower release form then Blood meal above for cannabis. It will also break down into calcium, magnesium, sulfur, manganese, iron, copper, boron, and zinc that will all be usable by your plants.
- Worm Castings – One of the most important parts of creating high quality organic cannabis soils is worm castings. Worm castings are already composted so they are ready to work as soon as you add them to your new reusable cannabis soil. There will come billions of organisms in them such as bacteria, protozoa, fungi, and protozoa, all important soil life that will help break down all the other organic nutrients that we added to the soil above. If you would like to learn more about worm castings we recommend this excellent overview article here.
We highly recommend worm castings for any organic cannabis soils you are or will be creating for best growing results from your plants. Research also suggests that all these types of micro-life in the soil will also help to create a better terpene profile for your cannabis buds during flowering and harvest.
Do I need to Measure Out your Amendments?
Well it’s really up to you, reusing your organic cannabis soil will allow you to keep everything without any waste and the good news about organic reused soil is that organic will not burn your cannabis plants no matter how much you intend to use. For this reason we recommend using a couple cups of each of these above per gallon of soil.
This is where you get to play around and see what works best for you during each growing cycle. If you are having cannabis nutrient deficiencies during your first growth or subsequent reuses, then you may need to add more amendments for your next garden depending on the deficiency that your plant suffers from.



Your Soil is Created Now What?
Now it’s time to mix all your amendments very well with the organic soil. Make sure you mix this in very well, to create an even distribution in the soil. Add this to your cannabis growing containers and you are ready to start growing your cannabis plants. You can even use your extra worm castings to start your cannabis seeds. Cannabis seeds do awesome germinating in worm castings and will get off to a great start with everything they need right away.
Top Dressing and Watering
It is important to top dress with a small amount of these amendments as you grow your cannabis genetics. Growers can do this by sprinkling a small amount of each around the base of the plant every couple of weeks. Some of the most important roots on a cannabis plant are the upper roots that are close to the surface of the plant’s soil. These roots get the most amount of oxygen making them very important and top dressing will help the massive amount of bacteria living here and the roots.
What to do with your Reusable Soil Post Harvesting
So, your cannabis harvesting is completed and you are left with your pots, a cannabis growing stump, and your soil that was created.
First things first, take all the containers and empty them into an area where you can break up all the rootballs and soil. Mix all of your reusable soil together and it is time to start re-amending your next cannabis grow. This is where you will add back many of the same organic nutrients that were used up in your last growing cycle.
Your plant used up many of the nutrients to grow to harvest and to reuse your soil you will need to replenish them. Luckily this is easy to do with organic growing. It’s time to add back half of everything (except worm castings add the same amount if you have them) that you added the first time to your soil. This is also a great time to adjust your needs for the soil between each reuse. Once again mix everything in well, you can also let your soil sit for a few weeks once again to allow some breakdown time for the nutrients or you can just use it again right away. Be sure to add water to this mix, this will also help to promote more microbiology growth.



Do Old Roots and Leaves Matter?
When the soil is recycled it will undoubtedly contain old roots and leaves, this is nothing that you will need to worry about when it comes to reusing your soil. In fact these are just another important organic amendment in your reused soil. What better contains all the important minerals and nutrients then these old roots as they once again are broken down by all the microbiology in your pots. These old roots and leaves will be another essential element to regrowing our new cannabis plants in their pots for the next indoor cannabis garden.
How much money can you save with organic cannabis soil reuse?
Well this will obviously depend on how many plants that you have in the garden but we will do a baseline savings. So if you are using one bag of Happy Farm soil and it is about $40 a bag now with inflation. We will say that you can do four, three gallon pots with this one bag. We will estimate a 3 month growing cycle, so four growing cycles per year.
If you were to not reuse your organic cannabis soil, you would be looking at a cost of about $140 dollars per year not including taxes where you live. We have reused soils for up to five years, so this would be a savings of about $700 over five years of growing your own cannabis plants!



Final Thoughts
With so many costs for growing your own cannabis plants, organic cannabis soil reuse is a great way to save money every single grow. It’s always nice to save a few dollars, so you can spend it on great cannabis seed genetics, bigger lights, or even some summer cooling. We hope this article will help you to save money and have great plants reusing your cannabis soils.