Beyond the hydroponics or soil matrix, foliar feeding is an increasing technique whereby nutrients are directly sprayed onto the cannabis plant leaves. The method can be an excellent addition to the producer’s toolbox as a rapid fix for specific plant nutrient deficiencies. To avoid such issues, growers must, nevertheless, understand and manage its specific limitations and drawbacks. Some supporters doubt the technique’s efficacy, despite its claimed benefits. This paper will explore the scientific ideas underlying foliar feeding, its benefits and drawbacks, and provide direction on how often to foliar feed for the best outcomes in cannabis growing.
What is Cannabis Foliar Feed? A Technical Review
Direct liquid nutrition treatment for cannabis plant leaves is known as foliar feeding. Unlike root feeding, which uses hydroponics or soil media to supply nutrients, foliar sprays avoid the root system and provide minerals by stomatal and cuticular absorption.
Mostly on the underside of leaves, tiny pores called stomata let leaves absorb nourishment. Furthermore, if surfactants are used correctly, the waxy cuticle of the leaf can also absorb some nutrients. When compared to soil- or substrate-based feeding, this direct absorption path speeds up the rectification of some nutrient shortages.
Still, folious feeding is not a panacea. Nutrient type, concentration, climatic circumstances, and plant stage of growth determine its efficiency. Applied deliberately, it can greatly improve plant health; misuse can cause nutrient imbalance, leaf blistering, or disease growth.
Benefits of Foliar Feeding Cannabis
When cannabis plants are severely deficient, foliar feeding is also best. Under such conditions, root binding, pH, or excessive watering can all impede root absorption. Applying chelated micronutrients—such as iron (Fe), magnesium (Mg), or calcium (Ca)—directly to leaves can help us see visual improvement in 24 to 72 hours.
Enhanced Nutrient Performance
Sometimes the restrictions in cation exchange capacity or less than perfect substrate conditions cause absorption of nutrients through the roots to be ineffective. By providing minute but effective amounts of essential micronutrients without altering the soil EC levels, foliar sprays are able to offset this. Targeted application lowers the possibility of nutrient lockout and salt accumulation.
Extra Feeding at Crucial Points
Cannabis plants may benefit from extra foliar sprays of nitrogen (N), phosphorous (P), and potassium (K) at periods of great demand like pre-flower stretch or veg growth later in the cycle. Should root absorption be less than plant metabolic need, foliar spraying provides a steady flow of macronutrients.
Foliar Spraying Risks and Limitations
Limited Absorption Capacity
Though its advantages abound, foliar feeding is not without risk. The plant’s limited ability to absorb significant nutrients through its leaves presents a major obstacle to this approach. Nitrogen, phosphorous, and potassium are less likely to be absorbed even if other micronutrients like iron and manganese can be taken rapidly and well. This makes foliar feeding a complement rather than a substitute for an equilibrated soil or hydroponics nutrient program; rather, it is a tool for particular situations.
Moreover, the molecular weight of the nutrition solution might affect the absorption of nutrients via the leaves as well. Generally advised to be given in folious feeding are chelated forms of nutrients as less soluble, larger molecules are less accessible for absorption by the leaves of the plant. Nutrient solutions should be formulated correctly so that the nutrient is presented to the plant as a form accessible for absorption.
Phototoxicity and Leaf Burn Risk
Leaf burn and phototoxicity are one of the main hazards associated with foliar feeding. Water droplets can behave as magnifying lenses, focusing light and generating burns on the leaf surface when nutrient solutions are sprayed upon them. This is especially unwelcome when foliar feeding takes place during the time of day when the sun’s rays are most strong or under very brilliant artificial growth lights. Under such circumstances, foliar sprays can permanently burn the leaves, stunt them, and lower the general health of the plant.
Under low-light, like early morning or late evening, foliar feeding should be done to reduce the danger of phototoxicity. Foliar feeding should be done near lights-off for indoor cultivation to avoid subjecting the plants to intense light just after treatment. This method lets the plant get the nutrients without increasing its burning danger.
Increase Disease Pressure
If done incorrectly, foliar spraying might increase the likelihood of plant diseases. For fungal diseases including powdery mildew, botrytis, and downy mildew to flourish, leaf dampness provides an ideal habitat. Extended periods of water droplets on the leaf surface can lead to mold and mildew development, which can swiftly migrate to the remainder of the plant.
Early disease detection depends on consistent observation of plant health following foliar feeding. Growers must keep the growing area clean and aired to stop the spread of disease-causing bacteria and pay strict attention to any mold or mildew conditions that develop.
Best Strategies for Foliar Feeding Cannabis
Appropriate Environmental conditions and Timing
Successful foliar feeding depends also on timing. Applied at times when the stomata of the plant are open and receptive for nutrient absorption, foliar sprays should Typical instances when this occurs include early morning or right before lights go off indoors. The plant’s stomata will most likely stay open during these times, which facilitates efficient nutrient intake.
Effective foliar feeding depends also on environmental factors including temperature, humidity, and air movement. Higher vulnerability to illness can occur from too high humidity extending the presence of water droplets on the leaves. Consequently, foliar feeding under excessive humidity is to be avoided. Furthermore, extremely high or low temperatures could affect foliar nutrient absorption efficiency. Between 18 and 24°C (64 and 75°F), foliar feeding should be based on IFormaximum nutritional intake.
The supply of enough ventilation in the growing environment is the second main factor. Good air movement reduces fungus’ causing power and facilitates quick evaporation of the nutritional solution. You can position the plants on a fan or in an area with enough airflow to achieve fast drying of leaves and disease avoidance.
Choose the Right Nutrient Formulations
Applied in foliar feedings, not all nutrients are created equal since some of them are too harsh to be sprayed straight or too big to be absorbed into the leaves. Soluble and readily available in chelated forms, the ideal nutrients to employ in foliar feeding include Chelated nutrients’ small molecular size helps the plant absorb them more effectively.
Usually applied folially since they are more easily absorbed by the leaves, micronutrients including iron, magnesium, and calcium are used. Products are applied chelated forms including Fe-EDTA, Ca-EDTA, and Mg-DTPA. For best absorption, they make sure the micronutrients are in the solution and can readily pass the leaf cuticle and stomata.
Usually include surfactants or wetting agents in addition to nutrients, foliar treatments ensure coating the solution evenly over the surface of the leaves. Mild soap, non-ionic surfactants, or yucca extract all help the fluid stay to the leaf better and lower running off risk.
Conclusion: Is Foliar Feeding Worth it?
Foliar feed cannabis is a powerful tool for cannabis farmers as it allows for the quick and precise correction of nutritional deficiencies. When utilized under suitable conditions and for the right goals, it may also be a quite useful extra practice even if it should not be replaced for conventional soil or hydroponics feeding. If one knows the art of nutrient absorption as to apply and the recipe for the nutrient solution, then one is successful. Applied sensibly, foliar feeding can improve plant health, raise yields, and offer a faster fix for problems in cultivation. Growers can fully utilize foliar feeding to maximize cannabis production using the correct technique and awareness of probable hazards.
