Growing experts talk about foliar feeding in comparison to soil feeding (or medium/root feeding) for a grow system, as these are the major and only sources of nutrients for the plant and its growth.
Usually, growers use the foliar applications for very specific purposes, such as in the case of a bug infestation or to coat the leaves of the plant with beneficial fungi and bacteria (compost teas). However, it should be noted that foliar feeding during the later stages of flowering does not give worthwhile results. The risk of damage outweighs the benefits of feeding this way. This means that foliar feeding should not be used after the first couple weeks of the flowering process has begun. At this stage, not only will the plants’ leaves potentially get clogged, but the extra humidity created by transpiration and rapid water usage at this stage results in conditions just begging for root rot or stem rot.
It should be specified that foliar feeding is not an alternative to root feeding; it is an additional way to provide the plant with nutrients and increase the rate of nutrient absorption rather than the total amount of nutrients absorbed.
Advantages of foliar feeding:
- Maximizing yields
- Crop Quality Improvement
- Can speed up the vegetative process
- Easy way to keep bugs at bay
- Not useful in late flowering stage
- If applied indoors, the water droplets can act like a magnifying glass and burn the plants.
- Most organic compounds need to be emulsified before they can be sprayed. Otherwise, they will not dissolve in water.
It is recommended to use foliar feeding only until your plant reaches the flowering stage. Foliar feeding until this point is perfectly viable. Most plants require thorough coatings of the surface and undersides of the leaves when fed this way. This can be strenuous task with a simple hand sprayer and a large number of plants in that frustrating middle region where there are a lot of plants to take care of, but not enough to warrant or justify the use of a mechanical sprayer.
Soil feeding is the most simple and most commonly used technique to feed plants. In this process, the medium acts as a contact surface through which the plants absorb nutrients via their roots. Several growers do only this for the entire duration of the plants’ lives without ever foliar feeding, and this has not been found to produce a large difference in yield or quality of the final product.
One of the hydroponic growing experts says, “I like to experiment with all the latest trends and technology in the growing world because you never know when you’ll stumble onto some great, new growing technique that will improve your overall quality and yield.”
In a hydroponic grow system, the roots of the plants absorb nutrients directly from the nutrient rich solution, and is more about the question of whether or not to foliar feed at all.
Disadvantages of soil feeding:
- Nutrients added in excess will cause exponential damage to the plants (commonly referred to as nutrient burn).
- Hardware (various meters) are required to ensure that the concentration of nutrient solution is ideal for the specific stage of the plants life.
- In all methods of cultivation apart from organic soil mixes, where the sources of nutrients (compost, seed meals, etc.) are pre-mixed with the soil prior to planting, skipping or missing a plant’s feeding session can result in immediate and drastic nutrient deficiencies.