The benefits of using a molasses foliar spray

molasses foliar spray
Molasses Foliar Spray

Molasses are an often-overlooked, valuable addition to any feeding schedule, not only is it high in nutrition, it carries a wide range of benefits from being an organic, natural insecticide to preventing salt build-ups, It can be applied directly to the growing medium via your regular feed or as a foliar spray.


Molasses, also known as black treacle is a highly viscous and dark substance that is made during sugar refining, once the sugar has been boiled down, crystals are extracted from the syrup and the remaining product is molasses.

Different types of molasses exist and vary in thickness and sweetness, usually as a result of different processing methods, molasses made from cane sugar is usually made into sweeteners and if you’re in the UK – It’s made into the familiar lollipops that come out during bonfire night.

On the other hand, when molasses are made from sugar beet juice, it often has an awful smell as well as a bitter taste and isn’t typically used in food and so is typically used in animal feed.

This is why it’s important to note that not all molasses are suitable for growing, some lower quality molasses can contain unwanted additives and chemicals that you certainly don’t want to be feeding your plants, never mind a foliar spray.

Make sure that when you’re choosing molasses, you go for a chemical-free, organic and most importantly un-sulphured product.



All molasses inevitably will contain some sulphur, however, some types of molasses have additional sulphur from the manufacturing process where sulphur dioxide is added to the sugar cane to act as a preservative and anti-oxidant, these are known as sulphured molasses and are unsuitable for feeding plants.

Make sure that you buy organic, un-sulphured molasses when using to feed your plants otherwise the sulphur will kill the bacteria and microorganisms in the soil.

I’d recommend using Grandma’s Unsulphered Molasses, I’ve had excellent results with this brand, It dissolves fast and makes for an easy foliar spray


Molasses are a great supplement, follow these easy instructions and you can make your own foliar spray in no time.

  • Ph 1 Gallon (4.5l) of water and let it sit out for 6 – 12 hours

    If you’re using tap water, I always advise to let it sit in the sun or under your grow lights, preferably overnight to kill any chlorine that is present.

  • Add your base nutrients to the foliar feed

    Add any nutrients that you would normally apply to your foliar spray before the molasses

  • Add 30ml of molasses per gallon of water

    Stir the molasses well to ensure it’s fully dissolved otherwise, you may get blockages when foliar spraying.

  • Foliar spray your plants thoroughly

    Leaves take in nutrients via pore-like stomata’s on the underside of the leaf, this is why it’s important that you foliar spray the under of the leaves as well as the top.

    It’s recommended that you foliar spray in the morning, approximately 1 hour before the lights come on and when the lights are off in the night time.



Foliar sprays are best applied in the morning, around an hour before the lights are due to come on. This is when the plant’s stomata’s (similar to pores) are most open and have the highest rate of absorption.

Applying your molasses foliar spray when the lights are turned off will also eliminate the risk of burns as when water droplets are under powerful lights, they magnify the light source effectively causing burnt spots.

Don’t use a molasses foliar spray late into flowering as the sticky residue can be left behind on the trichomes affecting the taste of the final smoke.


If you’re used to growing in soil, you will have no doubt heard of the phrase “feed the soil, not the plant”. Molasses are a rich source of nutrition, extremely effective at feeding the organisms that live inside the soil and greatly improve the quality of the soil. 

High in calcium, magnesium, iron, and potassium, as well as a host of other micronutrients, molasses are an excellent choice for any soil grower as it not only provides essential nutrients, it is also a great source of carbohydrates for the organisms that live in the soil.

Dry molasses can be added during the blending of the soil prior to planting your seeds, It’s sold as dry molasses and despite the name, It’s actually made from soaking (usually) rye grain in molasses.


There is more than one way that you can begin incorporating molasses into your grow. Molasses can be used as part of your regular feeding schedule, during soil preparation or both, the easiest and most common way to include molasses is in your watering schedule.

Begin by simply dissolving molasses in your regular nutrient feed and apply as you would usually feed your plants. When it comes to selecting a dose, you should start with 1-2 tablespoons per 5L (1Gal) of water. 

It’s also good to note that using lukewarm water will make it much easier for the molasses to dissolve, use this initial dose as a starting point so that you can further assess how the molasses affect your soil and plants, adjusting the dosage of molasses accordingly. 

By starting with a small dose you can help prevent unnecessary stress or risk of nutrient burn to your plants, especially during the vegetative stage. In most cases, the effects and benefits of the molasses will be mostly noticed during the later flowering stage although it is still good practice to use it throughout the entire life cycle.

molasses foliar spray

As with adding any new additive, it’s important to keep an eye on the pH level of your soil.


A common problem many growers fact is salt build-ups from non-organic nutrient build-up that occurs naturally in the soil over time. When enough salt accumulates it can alter the pH levels of the soil eventually leading to disastrous nutrient lockouts.

Molasses are effective in combatting salt build ups even after a single application.

I’d like to thank you for reading our post on The benefits of using a molasses foliar spray, we try our hardest here at and highly appreciate any comments left on our site.

Author: tgallone

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