Foliar Spray During Flowering? | Best Nutrients for Cannabis

Foliar Spray During Flowering?

Foliar Spray During Flowering?

Should I Foliar Spray During Flowering?

foliar spray during flowering

Foliar feeding is an excellent way to provide vital minerals and essential nutrients directly to your plants through the leaves. If you’ve been applying a foliar spray to your plants during the vegetative stage, you may now be wondering – should I foliar feed during flowering?

Well, there are many mixed opinions amongst growers when it comes to foliar spraying buds, some growers will absolutely reject the idea whilst a small number of growers have and continue to use this method.

Foliar Spray Feeding for Indoor Growers

When a cannabis plant begins to enter the flowering stage, it is generally advised that you stop foliar feeding after the third week of flowering.

Cannabis will secrete a sticky resin to act as insulation for when the environment is hot and dry, this helps to keep the plant cool and locks in essential moisture.

If you decide to foliar feed during the flowering stage, then it’s very important that you introduce additional airflow to decrease the temperature and humidity of the growing environment.

This will avoid contaminating the plant’s resin with your nutrients, If left to contaminate the buds this can leave a harsh taste on your final smoke.

Why would I foliar feed during flowering?

foliar spray during flowering

In case you are wondering, why would I foliar feed during flowering if the general consensus is against it?

Well, the main reason growers foliar feed during this stage of growth is usually to treat a nutrient deficiency such as Potassium/Phosphorus, to treat an aphid infestation or to cure fungal diseases such as White Powdery Mildew which can ruin a crop if present during the flowering stage.

Furthermore, some growers like to apply PK boosters during the flowering stage to give their plants a head start, with foliar feeding being the most efficient and quickest absorption route for the plant, with outstanding results if done correctly.

It’s only recommended that you foliar feed until about 2 to 3 weeks into flowering.

Foliar Feeding to correct a deficiency:

Foliar feeding for nutrient deficency
Nutrient Deficient Cannabis Plant

If your aim is to correct a nutrient deficiency, then you should be using nutrients that are specially created for soil or hydroponics as these contain higher levels of micronutrients which are ideal for foliar feeding.

In most cases, you should always mix the nutrients at a quarter to half the strength labeled on the bottle to avoid nutrient burn.

Remember to foliar feed when the lights are off, preferably in the morning, a feed of strong nutrients coupled with bright overhead lights can cause the water droplets to be magnified and cause your leaves to burn.

Because of this, foliar feeding is best done with a mist style sprayer as smaller particles will result in a better response from your plant and less large droplets will have formed mitigating the risk of light burn.

foliar spray during flowering


I’ve found some quality & low price sprayers:

• Amazon – N-150 1.3Gal pump mist-sprayer
• Amazon – Chapin 48oz mist-sprayer

How to foliar feed during flowering:

Starting either in the morning, roughly an hour before the lights come on, or in the evening when the lights are due to go off (the evening is better as more stomata are ‘awake’).

If possible, you should aim to foliar feed your plants in the evening, preferably an hour before the lights go out as this is the peak time where stomata are ‘awake’, alternatively you can apply a foliar feed in the morning, roughly an hour before the lights come on.

Prepare your spray bottle with your nutrients solution containing 25% of the recommended dosage, to begin with, carefully spray the leaves of your plants, including the underside of the leaf trying to avoid spraying the buds directly, this should be repeated at the same strength for up to three weeks.

If after the first week there is no sign of improvement for the deficiency, you should increase the concentration of the nutrients by a further 25% until the defect is remedied.

A few important things to note before you begin foliar feeding are:

  • Increase airflow and lower temperature/humidity.
  • Spray with a fine-mist spray bottle.
  • Mist at least once per day in the early morning, preferably an hour before the lights come on.
  • Make sure that you are using soil or hydro nutrients, packed with micronutrients for maximum benefit.
  • Mix nutrients at 25 – 50% of their described strength.
  • Spray the entire cannabis plant.
  • Stop misting 3 weeks into the flowering stage.

Check your humidity levels!

If you need to foliar spray feed during flowering, you will be increasing the humidity levels quite significantly.

High humidity during flowering can lead to stunted bud development, a loss of resinous oils and odor as well as the increased risk of fungal diseases such as White Powdery Mildew or bud-rot which thrives in high humidity and can devastate a crop.

During flowering, you should aim to have a relative humidity level of 40-50%, preferably on the lower side if possible, If you are introducing foliar feeding, you should increase airflow and lower the humidity to 20-30% until the nutrients have been absorbed.

Don’t forget to spray under the leaves!

When you begin to apply the foliar feed to your plants, make sure that you spray the entire plant – in particular the underside of the leaves.

The main reason for this is that the majority of the leaves stomata are located on the underside of the leaf, this is the where the nutrients are rapidly absorbed.

If you’re treating pests or a fungal disease, this is their favorite hiding place so it’s important that you don’t miss it.

How does Foliar Feeding work?

Foliar feeding essentially means that you spray nutrients directly onto the leaves of your plant. This provides nutrients via foliage rather than the roots.

Foliar Feeding has been the subject to multiple scientific studies, prompting growers to use it in their growing regimes.

A daily foliar spray feeds the plant via its stomata (a pore within the leaf responsible for taking in water and releasing CO2) with direct nutrients. Regular spraying also provides clean and open stomates for your plants which help to increase the rate of photosynthesis.

What are the benefits of foliar feeding?

  • Plants can uptake and absorb nutrients up to 10x faster through the leaves as opposed to the roots, this is not to say that regular feeding can be replaced by solely foliar feeding.
  • If you suffered problems with aphids/fungus during the vegetative stage, you may want to prevent this from spreading into the flowering stage using an organic, natural fungicide.
  • Applying a foliar feed such as Liquid Light from Dutch Masters during the flowering stage is an excellent way to boost photosynthesis.
  • You are immediately able to tackle nutrient deficiencies.

2 Comments

  • Armando Murzynski says:

    Saved as a favorite, I love your web site!

  • Lucilla Moriconi says:

    With enough air flow your plants shouldn’t get moldy buds or burns from water droplets. With that being said, if you want a MAJOR boost in production spray with MetaNaturals Organic 1-5-5 during flowering. This stuff is boss, I normally stop foliar feeding half way through flowering and still get a boost from it.

Leave a Reply


Name (required)

Email (required)

Website