High-frequency fertigation (HFF) means irrigating with nutrient solution several to many times per day, often from 4 to 20 or more small events in the light period, instead of watering thoroughly every few days. The root zone stays close to container capacity with a steady nutrient concentration, so water and nutrient stress never build up.
In practice
HFF is used mostly with coco and rockwool on drip systems, because they drain fast and hold plenty of air even when wet. Each event is small, sized so that runoff accumulates to the target fraction over the day. The approach lets growers use smaller containers: the medium no longer has to store days of water.
Myth check
House position on pot size: big things come in small packages if you push nutrients and water hard enough. The founder has harvested more than 4 oz (113 g) dry from a 16 oz (about 0.5 L) cup with high-frequency fertigation. Pot size is a trade-off against feeding frequency, not a fixed rule. Evidence: Grower practice, house-endorsed. See drain-to-waste and crop steering.
Don't confuse with
- Crop steering: may use HFF in its schedules, but deliberately varies dryback.
The root zone is the volume of medium or solution where a plant's roots live, including its water, air, temperature, pH, EC and microbes.Field capacity is the amount of water a medium holds after it has been saturated and allowed to drain freely; in pots it is called container capacity.Coco coir is a growing medium made from processed coconut husk, prized for holding water and air at once; it binds calcium and magnesium unless buffered.Rockwool is an inert growing medium spun from melted basalt rock into fibres, sold as plugs, cubes and slabs, that holds water and air in fixed proportions.Drip irrigation delivers water or nutrient solution through tubing and emitters directly to each plant's medium, in measured amounts on a timer or controller.Runoff is the water or nutrient solution that drains out of the bottom of a container after irrigation; growers test it to see what is happening in the root zone.Pot size is the volume of medium a plant roots into; bigger pots give bigger plants within reason, but feeding frequency can let small pots punch well above their size.Dryback is the drop in a substrate's water content between irrigations, usually expressed as a percentage of its content at full saturation.Fertigation is delivering fertiliser dissolved in irrigation water, so plants are fed every time they are watered rather than through solid amendments.
