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How to Foliar Feed Your Marijuana Plants

How to Foliar Feed Your Marijuana Plants

When done correctly, foliar feeding is extremely beneficial for marijuana plants. While this may go against the general school of thought, modern marijuana plants require regular misting and/or spraying. When a nutrient solution mixture is sprayed on the leaves, the plants absorb the nutrients.

Foliar feeding offers a considerable boost for your marijuana plants, ultimately providing you with a bigger, better, and more bud-filled harvest. With that in mind, though, foliar spraying can’t replace the standard root-feeding regimen. Instead, it offers a fast way to ensure your plant gets the supplementary nutrients needed.

While foliar feeding isn’t a method used by all marijuana growers, at some point, you will probably encounter a situation when the foliar spray is useful for your cannabis plants. From treating plants with natural protective solutions, fungicides, insecticides, and nutrient solutions, foliar feeding is a multi-use cultivation technique.

Even though foliar spraying doesn’t require any type of special growing abilities or skills, it can be beneficial to learn the right way to do it so that you get the best possible results. Keep reading to learn more about foliar feeding and when it should be used here. Understanding what to do, how to do it, and what products to use will help ensure the desired results are achieved.

How Foliar Feeding Works

As mentioned above, foliar feeding involves spraying the fertilizer directly to the plant’s leaves. In the past, this process has been the focus of several anecdotal and scientific studies and has prompted several growers to use it in their growing regimens.

With a regular regimen of spraying, your plant is fed through the stomata, which are the microscopic openings found between the two guard cells, ensuring nutrients go directly into the plant. Regular and proper spraying will also offer an open and clean stoma for the plants. Changes in the water content near the guard and secondary cells make it necessary for the stoma to shut or open, which is a basic response that occurs when the water status in the plant changes.

Feeding Your Marijuana Plants

Your marijuana plants will continue the process of photosynthesis by mixing several ingredients in the leaves. The materials are often gaseous (i.e., carbon dioxide), liquid (i.e., water), and energy (i.e., light). Just looking at the leaves of your marijuana plant will provide insight regarding how it creates food.

The stomata are essential for providing an input and output route for gaseous material exchanges. Essentially, the stomata are like tiny pores. If a higher level of carbon dioxide is needed to complete photosynthesis, then the plant’s stomata will open to receive more CO2.

Foliar feeding offers several advantages. Understanding these advantages helps you figure out if it is a method you should use. The fertilizers that are applied through the foliar feeding process are typically three to five times more effective than the more standard fertilizers applied directly to the roots. With foliar feeding, you can also mitigate the stress plants endure due to subpar nutrition. The nutrients provided by foliar sprays also help to make the elements, such as iron, much more accessible to your marijuana plants when they are not present in the water, soil, or the hydroponic solution.

Foliar Spraying for Insecticides and Fungicides

The use of foliar sprays is useful and common for treating your marijuana plants for an array of diseases and pests, including powdery mildew, mites, and more. A popular substance that many growers use that serves as a treatment for existing problems along with preventative measures is called neem oil.

With neem oil, you have a substance that is considered a natural insecticide that also offers a few fungicidal properties. Cannabis growers can use the neem oil foliar spray along with aloe vera juice and even a type of emulsifier, such as potassium silicate, to help dissolve the oil. Spraying your plants each week while they are in the vegetative phase will help to strengthen the plants while increasing their resistance to pathogens and pests.

If the foliar spray you are using is created using potassium soap (also called insecticidal soap) it is a great option to combat insect issues. It is especially effective against an aphid infestation or problem, which are considered some of the most common pests seen on marijuana plants. Using a mix of neem oil that is dissolved in potassium soap will be even more useful. The potassium soap will eliminate the pest as soon as it is applied, and the neem oil will prevent additional attacks, all while helping to strengthen the defenses of the plant.

There are several other natural ingredients, including everything from plain milk to cinnamon oil, nettle, and cayenne pepper that can help to prevent or fight powdery mildew. These substances are also beneficial for treating other types of fungal pathogens naturally and without harming your plants in any other way. If you search for these methods online, you will find several recipes to use that include these ingredients.

Eliminate the Possibility of Nutrient Deficiencies with Foliar Spraying

Foliar spraying is an ideal option for correcting any nutrient deficiencies due to how quickly absorption occurs through the plant’s leaves. The results will be virtually immediate. The best time to spray/feed your plants using this method is in the early part of the morning if you are growing outside, and any time the light comes on if you are growing your marijuana seeds inside.

The plant’s stoma will open when the light comes on. It is worth noting, though, if the temperature reaches 80°F or higher, the spray will not be as effective because many of the stomata are going to close.

Seedlings, younger plants, clones, that are in the vegetative state will benefit thanks to the foliar feeding method. Because the clones are not rooted, they need foliar feeding to begin the root development process and to avoid yellow discoloration, which is a common problem with cloned marijuana plants.

When the marijuana plant moves into the flowering stage, it is best to halt all foliar feeding. When the environment around the plant becomes dry and hot, it will begin to secrete a type of resin for insulation purposes. This is a natural process that helps to keep the plant cool. If you are using foliar feeding during the flowering process, it’s a good idea to reduce the temperature of your plants to make sure the fertilizer doesn’t mix with the naturally produced resin.

Experts suggest that you only use foliar feeding during the vegetative state until approximately two weeks into the flowering process. You want to ensure your plants don’t have any type of residual nutrients on the surface when it is harvested. If this happens, it will create a dense and nutrient infested smoke.

The Foliar Spray Process

Any type of fertilizer that is created for hydroponic systems or soil is ideal for foliar sprays, especially the ones that have only trace elements or certain micronutrients. In most situations, you need to mix the fertilizers that are being used to reduce the strength and avoid nutrient burn or fertilizer burn.

A spray that has a more potent mix of nutrients should not be used for a plant that is exposed to bright light. That’s because intense light may create light reflection from the drops of water that will cause the leaves to burn. It’s best to use a mist-style sprayer for foliar feeding. The smaller particles being applied are going to offer a much better response from the plants. With this method, you can also use less fertilizer to help achieve the desired results.

Don’t Forget to Spray the Underside of the Plant

When you are spraying the mixture, make sure you are spraying the entire plant – mainly the underside of the plant’s leaves. There are two main reasons that this is necessary. There are many pests, such as aphids and spider mites that gather on the underside of leaves, where the stomata are located.

Be sure to take careful note of the proper nutrient strengths of the solution. In most cases, foliar feeding will require a much lower level of nutrient strength than feeding the plants by way of the soil. If the mixture that you have sprayed doesn’t indicate the proper amount for safe foliar application, just start with half of the recommended amount.

It’s a good idea to test the spray you plan to use ahead of time on a small amount of the plant. This is going to ensure that severe and permanent damage does not occur. Instead of going over the entire plant and crop without an untested mixture, use it on just one leaf, to begin with. Wait for at least 24 hours to see if any damage occurred before you move forward with the entire feeding regimen.

As mentioned above, do not use your mixture when the cannabis plant is flowering. If you spray cannabis flowers, several problems may occur. While this depends on the solution of spray used, it can cause an array of problems, including moldy flowers, undesirable tastes, and more.

If you are growing your cannabis seeds outside, rainy weather may soak your flowers. If you are spraying using fungicide because this is the only option for saving your crops from the possibility of a mold infestation, make sure you use a safe, natural, and a residue-free product to reduce the likelihood of damage or other complications.

Follow the Proper Safety Procedures

Make sure you are always following the set safety instructions for the spraying process. Some commercial sprays might be safer than some others, but you still need to make sure you take the proper safety precautions.

You want to avoid spraying any possible harmful substances without wearing adequate protection such as protective eye gear, a face mask, and gloves. Be sure you take special note of how safe or unsafe a product is for spraying on something that you will consume after the harvest. While there are some commercial fungicides or insecticides ideal for use on ornament plants, they may be toxic for veggies and your marijuana plants. As always, you need to make sure you follow the instructions provided with the spray being used.

Choosing the Right Sprayer

You will find that if you want to use the foliar method for feeding your marijuana plants, there are several sprayer options to choose from.

One option is a hand sprayer. These are useful if you only have a few plants that need treatment, or if you need something for “precision work”, like when you need to avoid spraying the buds.

Another spray option is a garden pump sprayer. These are sold with several capacities, including a shoulder strap making it easy to carry around while spraying all the plants. There are many of these sprayers that come with spray wands to make them even more versatile and convenient when spraying your plants with ease on all sides.

It’s smart to get both sprayer types, so you will have them available when they are needed.

An Overview of the Foliar Feeding Process for Marijuana Plants

If you want to use foliar feeding for your marijuana plants, use the basic steps to do it properly:

  • Spray using a fine-misting spray bottle;
  • Spray or mist your plants at least one time a day in the early morning or when the lights are turned on (if growing indoors);
  • Mix the root fertilizer (nutrient) at 50 % of the desired strength;
  • Make sure you spray your entire marijuana plant;
  • It’s best to foliar feed seedlings, plants in the vegetative state, and clones;
  • Stop foliar feeding two weeks into the flowering stage.


Foliar feeding is a method used by cannabis growers looking to supply various liquid solutions to their cannabis plants’ leaves. From neem oil to insecticidal soaps and fertilizers, foliar feeding provides various spray-on options for protecting and enhancing your cannabis crop’s yield and quality. Begin with high-quality seeds from i49 USA to get started.