I was recently approached by a budding young cannabis grower who wanted me to test a sample of his first grow. As this was his initial attempt growing marijuana (performed in his bedroom closet), I hesitantly accepted his gift, telling him I’d get back to him.
Bracing myself, I only took a small toke initially. The harsh, chemical taste and smell immediately filled my senses, initiating a painful coughing spree. He must not have read the chapter on flushing cannabis plants in his ‘How to Grow Marijuana’ guide.
Anyone can grow cannabis; it’s an easy plant to cultivate. Procuring a smooth, cannabinoid-rich flower, on the other hand, requires some special handling as the plant reaches maturity. One way to capitalize on a marijuana plant’s best performance in taste and quality is a process called flushing.
What Is Flushing?
Flushing is the term used to wash away excess nutrients in a cannabis plant as harvest time nears. It is a simple process of eliminating elements residing in a plant’s root system. Flushing a marijuana plant with only pH balanced water clears out any residual nutrients hanging out in the roots.
Removing fertilizer applications also stimulates the cannabis plant to begin using up all of its stored nutrient reserves. Providing only pH adjusted water keeps the plant alive while clearing out undesirable contaminants. As the plant reaches maturation, flushing produces a clean, pleasing flavour and smell, allowing terpenes and flavonoids to fully mature.
When to Flush a Cannabis Plant
Having grown the beauty from the start, you probably have a timetable of when your marijuana plant will finish. Checking trichome development as the plant nears maturity is one way of determining when to begin flushing. As trichomes start to turn from clear to cloudy, it’s time to rinse with pH balanced water only.
This protocol can vary, though, depending on what type of substrate is used to grow the cannabis plant. Hydroponic and soilless substrates require a much shorter time to rid the plant of nutrients. Usually, a couple of days is all that is necessary for a hydroponic system to eradicate the nuts. Coco and other soilless mediums, on the other hand, typically take between 3-7 days to flush nutrients from the plant.
Soil grown cannabis plants take longer to flush depending on the type of soil. A standard potting soil mix generally comes pre-packaged with enough nutrients to sustain the plant for a few weeks of life in the early vegetative stage. However, additional fertilizer supplementation is required throughout the plant’s life cycle to provide nutrition to the marijuana plant.
Because nutrients harbour longer in these types of soils, a seven to fourteen-day flush is required to clear out any remaining elements stored within the plant. An organic soil, rich in microbial life, does not require synthetic fertilization. Microorganisms present within a living soil break down elements present in the medium, providing the cannabis plant complete nutrition throughout its life stages. Organic, living soils do not require flushing due to the absence of nutrient applications.