If you’re looking for an easy way to increase growth and yield and avoid nutrient buildup in soil, foliar feeding is a great method. It’s pretty easy to do, all you need is to prepare a tea made of plant food, bat guano, or fish emulsion. Use foliar feeding during vegetative growth and early flowering. Late in the flowering season you shouldn’t use foliar feeding, as you’ll be eating the sprayed on nutrients later when you harvest. With foliar feeding, you should feed plants daily or every other day. You should also wash off the leaves with pure water so that the stomata on the leaves don’t get clogged.
There are specific times of day that are best for foliar feeding. Generally around 7-10 am and after 5 pm are ideal times. The stomata of the leaves, which are the parts that absorb nutrients, are open during this time. It’s also best to water when it’s a certain temperature. The ideal temperature is 72 degrees, but anything under 80 should work. If the temperature is over 80, the stomata will probably not be open. You should invest in a decent sprayer, because you want it to break up the water a lot into a fine mist. The solution you use should also have a very good pH level of between 7 and 6.2. Baking soda can be used to raise the pH, and vinegar can be used to lower it. Instead of watering occasionally and soaking the leaves, try to water a bit each day, and just give the leaves a fine mist.
Some growers have discovered a way to directly deliver oxygen to their plants. The method involves using seltzer water and nutrients. Whether you use this method or not, foliar feeding is a great way to deliver nutrients directly to the plant without risking mineral buildup.
Warning: It’s vital that you wash your leaves after harvest, before drying them. Many plant foods are toxic if consumed by humans, so make sure to rinse the leaves thoroughly. Foliar feeding does have some downsides, and most growers agree that it’s not really necessary for hydroponic growing. But if you’ve been having trouble with nutrient buildup, then foliar feeding can definitely help out.