Washing out Cannabis Roots
Washing out cannabis roots is an extremely important process of the grow, and you’ll need to do it before harvesting your plants. There are quite a few advantages in doing this when it comes to smoking the final product, and you can also do it mid-grow to get rid of excess salts and over-fertilization.
Plants get their food from salts in fertilizers, and you can use both chemical and organic fertilizers. We mix the fertilizers in with the water and then plants absorb them through the roots to then spread them around the plant. Usually, when you water the water and fertilizer is spread all over the soil and in some cases the water might be absorbed but the nutrients stick around in the soil. This is why we always recommend watering with fertilizers on and off so that the plants can correctly absorb the nutrients that are left in the soil and so that they don’t accumulate.
Roots are capable of absorbing liquid with up to a certain amount of nutrients; think of it like mixing up some hot chocolate with a ridiculous amount of coca powder and trying to drain it through a paper filter; the more powder in the milk the less milk will be able to filter through the paper and eventually it just wouldn’t happen. If you use too many fertilizers in your irrigation water then your plants won’t be able to absorb anything, not even water. If this happens then your roots and soil end up with a load of back up salts and it will eventually die of thirst if this issue isn’t resolved. To fix this issue of excess salts you’ll need to wash out the roots. Then, once the earth or soil is dry again you’ll need to build it back up with extremely small dosages of fertilizer and little water until it starts feeding again. You can even use enzymes to revive old and rotten roots.
Another issue that can sometimes happen is over-fertilizing with specific nutrients until the plants begin showing signs of excess. There are a lot of nutrients that can provoke this reaction, but macronutrients such as the famous NPK are more prone to cause such issues. Once you reach the flowering period, you might think that using more fertilizers will create more buds, but this isn’t necessarily true. Signs to look out for are dark green leaves and leaves that are easily broken and torn; this is a sign of excess nitrogen in the soil. If the leaves get wrinkly and thin, then there’s an excess of phosphorus. All of these issues can be solved with a simple washing of the roots.
Once your plants are ready for harvest and you’re planning on cutting them down, you’ll need to flush out the nutrients left in the roots and soil to get the cleanest harvest possible with a pure weed taste rather than chemicals or fertilizers. This is also done so that the leaves don’t have such a high chlorophyll content which is what causes that green, leafy taste. When you cure the buds, apart from transforming the cannabinoids you also rot the chlorophyll from the leaves, leaving you with a clean and pure weed. To get this right you need to make sure you flush out the roots before harvesting and wait until the leaves get kind of yellowish and for the soil to dry out completely before harvesting the plant.
How to flush out cannabis roots:
To flush your cannabis plants’ roots all you have to do is water them with abundant water until the soil is completely free of any fertilizers. You don’t need to have the water too cold, around 20-22º is fine; if the water is too cold you’ll stress out your plants and if it’s too hot it could rot the roots.
There are many different ways to do this, and the most common way is to stick your plant in the bathtub or shower and use the showerhead to water it. Wait until the resulting water coming from the pot is practically clean and you’re done. You’ll notice that once it starts coming out there will be a lot of stuff that comes out with it, and the cleaner the water the more effective the wash.
You need to avoid flushing your roots too late at all costs because the roots will hardly absorb any water at this stage and if you water them too late the buds might end up rotting due to having too much humidity. If you’ve waited too long, the best thing is to just water without fertilizers until its ready so as to avoid the risk of rotting the roots.
Another way to wash out your roots is with specific products for said process that act like a sponge and trap all of the remaining nutrients and salts. This works much faster than just using water, as it leaves the roots sparkly clean as well as the soil. Some products that do this are Flawless Finish by Advanced Nutrients or Final Flush by Grotek.
When using this products all you have to do is begin watering with them during the last 10 days of the grow and then wait for the soil to dry before you harvest.
If you’re growing in hydro it’s much easier to do, as all you have to do is fill the tank with water and leave it like that for a few days. If you’re growing in hydro trays, then you should directly remove the drain and clean the water out 5-10 times.
Now that you know how it’s done, you can fix your plants nutritional excesses in no time. Happy growing!
Author: Javier Chinesta
Translation: Ciara Murphy