Flush
Category: Cultivation · Level: Intermediate
Flushing is a cultivation practice of watering cannabis plants with plain water during the final weeks before harvest to clear nutrient residues from the substrate.
Flushing involves irrigating cannabis plants exclusively with clean water (without added nutrients) during the final 1–2 weeks of the flowering cycle before harvest. The practice is based on the belief that clearing accumulated nutrients from the growing medium improves the final product's flavor and smokability by reducing harsh mineral flavors. Flushing practices are common in soil and hydroponic cultivation but remain debated in the industry — scientific evidence for significant flavor improvement through flushing is limited and contested. Cultivators using organic growing methods or coco coir substrates often have different flushing protocols than those using synthetic hydroponic nutrients.
Also known as
Nutrient flush, Final flush
Usage
- Cultivation
Related terms
- Hydroponics — Hydroponics is a method of growing cannabis in nutrient-rich water solutions without soil, enabling precise nutrient control and faster growth rates.
- Flower — Cannabis flower refers to the harvested, dried, and cured reproductive structures of the female cannabis plant, the primary form sold in dispensaries.
- Curing — Curing is the post-harvest process of slowly drying cannabis in controlled conditions to develop flavor, enhance potency, and extend shelf life.