Do I need to flush my cannabis plants?

When you hear ‘flushing marijuana’, be honest…do you think of getting rid of contraband? 

As more states and countries relax their cannabis prohibition laws (and, we expect, in general), that definition is becoming a thing of the past! But legitimate flushing of cannabis is a grower tactic that deserves discussion. 

What is flushing?

Flushing is a growing strategy that involves completely stopping nutrient feeding two weeks to a month before harvesting, thereby encouraging the plant to use only what nourishment it has already taken in to reach the finish line. The idea here is that nutrients naturally stored in the plant will be fully metabolized, and that more of the plant’s natural components by cellular volume will end up in the end product. 

Sometimes additives like lemon juice or Carboflush can be added to water to neutralize nutritious salts in the soil–making sure that the plants don’t continue to absorb what’s already soaked in.

Proponents contend that flushing leads to both better tasting weed, and a higher quality burn with less ash. 

Does flushing cannabis work?

In that flushing removes nutrients from the soil? Yes. In a higher quality of smoke? We can’t say. 

Old school growers, and their modern mentees swear that flushing is a necessary part of a higher quality high, citing increased smoothness and deeper flavors. However, on the other side, some growers say it isn’t necessary to stop supplementation, and that feeding right up until the first snip is working perfectly for them. 

Ultimately, the only way to get close to a conclusion would be to stage a wide-scale blind taste test in adult-use states (no way this is going to be covered by a prescription), with flushed and unflushed weed. As to what neutral organization might fund that, we’re not sure. 

But tastes still remain subjective, and so a true answer will have to stay a pipe dream for now.