Contrary to popular belief, it is not necessary to go out and buy new soil every time you pot a new cannabis plant. Unless something is wrong with the old soil, such as an infestation, it is possible to reuse soil for new grows.

Composting soil

Take Care of Your Soil

Cannabis is notoriously greedy when it comes to nutrient intake. Whether it’s Calcium, Potassium, or Sulphur – your plants want to strip your soil of all the nutrients it has. How can you combat this? It is important to make sure that the nutrients in your soil are replenished regularly.

By making sure you maintain the health levels of your soil, you can eliminate the need to need to restore it when you go to reuse it. If you take care of your soil properly, then it should maintain a good level of health. Read on to find out how to keep your soil healthy.

Add Organic Matter

Adding organic matter to your soil is very important to maintaining the health levels of your soil. If you are able to keep a compost pile, that will really help with maintaining the levels of organic matter in your soil. Your cannabis plant will thank you for this. Your plants need this organic material in order to properly grow.

Organic Matter

Your marijuana plants need certain nutrients in order to grow and be healthy. Nitrogen, phosphorus, potassium come from fertilizer and organic matter; phosphorus and potassium also come from weathering of soil particles. Adding organic matter to the soil will replenish these nutrients.

Adding Air and Water

Soil

We all know that plants need water to survive. Like with all living things, water is one of the main building blocks of life. Your cannabis plant is no different. It requires water. But did you know that your soil requires air and water too?

You add water by regularly watering your plant. To add air, you can do an active addition or a passive addition.

The passive addition of air is done by agitating your water before you water your plant. The reason it is passive is that you are not actually doing anything to aerate the soil, you are instead aerating your water. You will need to agitate your water for a few minutes. Alternatively, you can use an air stone (like the ones used in aquariums) which will force oxygen into the water.

An active addition is done by aerating your soil. You aerate your soil by increasing the surface area of the soil. Carefully poke small holes in the soil around your plant. You do not want to damage the roots of your plant. You also do not want to introduce any pathogens into the soil. You can also aerate your soil by breaking up the surface of the soil. This carries with it the highest risk of damaging roots, especially if your plant is older.

There are some solutions that are able to add oxygen to your soil, but I would strongly recommend researching the toxicity of those products before using them.

Water carries with it, carbon, oxygen, and hydrogen; which are nutrients that help to maintain the health levels of your soil. Remember, to keep your cannabis plants healthy, water the soil. 

Some Other Nutrients

Here is a list of other nutrients you may need to add in small quantities:

-       Calcium

-       Sulfur

-       Magnesium

-       Iron

-       Manganese

-       Molybdenum

-       Chlorine

-       Boron

-       Copper

-       Zinc.

-       Many of these will be added when you fertilize your soil and marijuana plants.

Companion Planting

Companion plant mint

If you want to go a step further, companion planting is another useful way to keep soil nourished. Companion planting is the practice of planting other plants with your cannabis. You will need a much bigger pot than if you were just growing marijuana alone. Both plants will need plenty of room to grow.

An example of a great cannabis companion mix would be planting alfalfa, clover and marigold in with your cannabis plant(s). If you don’t feel like putting in the effort to grow two different plants in the same pot, you can always do crop rotation to assist with rejuvenating your old soil.

Altogether Now: Mixing Your Soils

The best practice for reusing soil is to mix old and new soil at a ratio of 1:1 (half old, half, new). This will create a situation where you are using new soil that has not had the nutrients stripped from the soil mixed with soil that you have been adding nutrients to. The old soil will have already produced results and the new soil will hopefully bolster those results.

Another benefit of mixing soil is that your cost for soil is cut in half. This way you do not have to put up the money for new soil every time you want to grow marijuana.

The Quality of your grow can also be altered by using new soil. It is no secret that every time you introduce a new aspect into your growing regimen, you introduce the possibility of new problems. By making sure that half your soil has had success, you can help to reduce any variances in the outcome of your grow.

What to Do with Unhealthy Soil

As I mentioned earlier, if your soil has become diseased or appears unhealthy for whatever reason, get rid of it. You do not want anything in your soil which will ultimately destroy your plant. Reusing soil of this nature is a sure-fire way to destroy your grow. Also if you reuse soil that has a disease or other malady which can spread, you run the risk of destroying your entire crop.

So when your soil is in really bad shape, you will want to replace it. I know we just talked about how it is important to reuse soil, but there is a point where reusing soil can be deadly for your cannabis. Don’t reuse soil that is diseased.

I hope this guide helped to shed some light on the benefits of reusing your cannabis soil.

Happy Planting!