What is foliar feeding?

Foliar Feeding is a process of giving your plants nutrients by spraying fertilizer directly onto their leaves. Foliar spray is usually made with the same nutrients and additives you feed your plant via the growing medium, but at a lower concentration!


Foliar spray can be very beneficial when your plant is showing signs of deficiencies. 


Most water are nutrients are absorbed by roots but leaves can also be helpful to absorption! There are times when foliar feeding can be of great benefit. Not only does it provide added nutrition, but it also allows for the grower to spend extra time with their plants which often results in problems being spotted and remedied earlier before they turn into larger issues! 


Any plant with leaves can benefit from foliar feeding!


When will my foliar feeding be most effective?

Your plant will always benefit from foliar feeding, but some conditions and stresses your plant is experiencing will make a foliar spray more effective. Anything causing issues to your plant's roots will benefit greatly from foliar feeding. When the root system is under stress, foliar feeding offers a potential lifeline to the foliage since water and nutrients may not be able to reach the top of the plant.


Root conditions include

  • Root disease such as Pythium
  • Water logged soil
  • Cold temperatures with low transpiration rates 
  • Clones which have an undeveloped root system
  • Nutrient lock up such as non-optimal pH levels


Redheaded Lady Foliar Spraying Plants

Rapid Growth and Development

When plants are growing rapidly and putting on a lot of bulk they can also benefit from additional foliar nutrients.  


How to foliar feed

It is best to foliar feed while the temperature is lower and the lights are less intense.

In an indoor grow, we recommend you foliar feed under green light an hour before the main lights turn on. Plants can't absorb green light so it won't interfere with the photoperiods. 

For outdoor grows, spray in the early morning before the sun becomes too intense. 

Lightly mist the entire leaf of the plant front to back, top to bottom. 

When experimenting with foliar feeding, we recommend starting out by just spraying one plant to see how it reacts before spraying your whole grow. 


The Dos and Don'ts of Foliar Feeding

  • Do Not: spray liquid onto light bulbs.  At the very minimum it will coat them with a film and make them less efficient.  It is also potentially dangerous as the sudden drop in temperature could make the glass explode. 
  • Do: Add oil or soap. In order for the foliar spray to stick to the leaves, oil or soap is often added to enhance absorption. Research what additive will be best for your particular spray. 
  • Do Not: make your foliar spray too strong. The spray should be kept at a low concentration so you don't risk burning the leaves. 
  • Do: adjust the pH. Always pH foliar spray before applying.  For young plants, a pH of 6.5 to 7.0 is ideal while more mature plants should get levels of 6.0 to 6.5.
  • Do Not: spray buds directly. Never spray onto dense buds as moisture can get trapped which can increase the chances of bud rot developing.  With their large surface area, leaves are the best for absorbing the spray.
  • Do: keep the misting light. Don't drench the plants until the liquid is dripping off. 


Remember, foliar feeding shouldn't replace your regular nutrient feeding schedule via the growing medium. Your plant will not get enough nutrition if they are only fed through foliar feeding. 


Bottle Spraying Leaves


Making a foliar spray

Before you make your foliar spray, you must make sure your nutrients are water-soluble. All Future Harvest liquid and powder additives and nutrients are water-soluble. All our nutrients and additives will work as a foliar spray except Royal Black - Royal Black takes time to break down before it can become available to the plant. We do not recommend it for use as a foliar spray as it works best in soil. 


How to use a foliar spray

When applying foliar spray to your plants, start slow with a gentle mist on both sides of the leaves. You can always spray more if you feel the plant is not responding to the feeding. 


How often to foliar spray

This is going to be dependent on the environmental conditions of the grow room! If the humidity is fairly low (under 50%) then it will be safe to spray more often: maybe 3-4 timers per week. On the other hand, if it's any higher (around 60% +) the additional moisture from the spray could push the humidity up, which increases the risk of an outbreak of pathogens.  


Never spray your buds directly! Foliar spray should be sprayed on the leaves only. 


Lady Spraying Leaves



Foliar Feeding Recipes:




Future Harvest Products used to make Nitro Boost


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Nitro Boost

Best for young plants. Low strength for stress relief with a little nitrogen boost!

- 1 ml Plantacillin

- 1 ml Prop-O-Gator

- 1 ml Super B+

 (Per Liter)



visual recipe for Bulking Tonic


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Bulking Tonic

To be used on healthy rapidly developing plants to give extra resources to maximize growth rate. 

- 2 ml Super B+

- 2 ml Royal Gold

- 2 ml Bud Boom (during flowering)

  (Per Liter)



Visual Recipe for Root Aid


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Root Aid

Pythium blend. Offering plants a lifeline in the case of root rot where nutrient absorption has been greatly diminished. 

- 2 ml Holland Secret Grow

- 2 ml Holland Secret Micro

- 2 ml Holland Secret Bloom

- 2 ml Plantacillin

  (Per Liter)



products needed for Green Up


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Green Up

Most yellowing plants are from deficiencies in either nitrogen, magnesium, or iron.  Calnesium contains all 3 and applying through foliar feeding will provide these crucial elements while any deficiencies in the root zone are corrected. 

- 2 ml Calnesium

- 1 ml Super B+

(Per Liter)⠀⠀




Good luck! And remember you can always reach out to @futureharvestdevelopments on Instagram if you have any questions or need advice.