To flush or not to flush, that is the question. Inexperienced growers usually neglect the flushing stage which gives them a yield that is simply not as good as it could have been. The opportunity of having better yield exists with flushing and it would be such a waste if it is ignored or done incorrectly.
First and foremost, what does flushing do?
Flushing is generally the process wherein a plant is fed with normal pH’d water in order to “force” it to use up the remaining nutrients already inside the plant before it is harvested. This makes sure that the plant contains no more nutrients upon harvesting. It is also used to remove excess nutrients and any salt builds up in a soil/coco/hydro setup. Since there are no more chemicals coming from the nutrients, flushed plants tend to have a smoother, more flavorful and less chemical flavor. In addition, black ash will not form when the herb is used. With that said, an exception to this would be organically fed batches simply because what was fed to the plants are easily absorbed as it went through the microbes in the soil first.
Next up, how exactly do we flush? Now that we know WHY we should flush, the next step is to learn HOW to flush.
First, the timing of the flush is important. Observe your herb. Look at its trichome or its pistils and observe if your herb is getting close to harvesting time. The usual timing of it would be based on how ready the herb is ready to be harvested. This means that flushing should happen only when your herb looks about it is near its harvesting period. Generally, this happens when around 50% of its pistils are turning dark and curling or when about 50% of its trichome is getting its cloudy hue. This step is incredibly important as the timing will determine what you will get in your harvest; early flushed and harvested herbs usually end up with the anxiety/paranoia effect while flushing and harvesting too late will end up being something like a sleeping agent. Wrongly timed flushing should be avoided at all cost as it will not only stunt the growth of your plant, the yield will definitely be below its capability.
The next step after determining the timing is preparing the water to be used in the flushing. As stated earlier, you would want to use a pH’d water. A common mistake of new growers is that they forget to pH their tap water. It’s important to pH the water that you will use because it ensures that the plant will still use up the remaining nutrients.
Now that we know what we will use, the next question would be how long will the flushing regimen continue? Generally speaking, the recommended time span of flushing your plant spans for about two (2) weeks. Going less might “under-flush” the plant which may give you a harsh tasting herb while going more than two weeks will likely stunt the growth especially because it is not feeding on nutrients.
The last part is to harvest and to cure your herb. After flushing for a number of days, your herb should be ready for harvesting and it will be ready for curing.
Even until today flushing is still very debatable as no one has attempted to simulate a proper experiment with controlled and variable groups. However, there are a lot who claims that proper flushing is very important to the end product. User experience and other self-experiments from other people say that flushing is very relevant to the point that some of them fully integrates flushing in their growing routine. Try it and see the results for yourself!