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Everything You Should Know About Flushing Cannabis With Molasses

December 28, 2022

The art of cannabis cultivation evolves as cultivators strive to maximize yields and bud quality. Many are learning to flush with molasses when growing weed plants and finding positive results.

Are you interested in cannabis cultivation and the multitude of methods people employ? The wide array of creative techniques to strengthen and enhance weed growth are fascinating.

Join us as we explore the purpose of flushing cannabis with molasses and explain everything you should know. 

Let’s dive in!

Why should you flush with molasses?

Molasses is a dark or light brown syrup made from refining sugarcane or beets. The viscous substance benefits cannabis plants in a variety of ways. There could also be some potential drawbacks.


Molasses contains carbohydrates, potassium, and other essential nutrients that help cannabis plants thrive. The substance also works in symbiosis with microorganisms to enhance your growing medium.

The process of flushing cannabis is essential for healthy plants. Using only water during various stages of your growth cycle keeps your medium clean and fresh. The procedure removes stagnating nutrients and minerals from your soil or hydroponic setup.

Applying molasses during a flush helps your weed’s development in fascinating ways, such as:

  • Energy and strength: Sugar is essential for cannabis plants to photosynthesize, feed, and grow strong. Molasses can enhance the process by boosting the natural carbohydrate concentration in your soil or water.
  • Higher quality medium: Molasses helps regulate other nutrients and microbes, promoting a healthy soil and water system. The substance kills bacteria, keeps your cultivation medium functioning, and helps avoid issues like nutrient lockout.
  • Better nutrients: Potassium is among the essential minerals marijuana requires. It also improves the movement of water and carbohydrates within a plant. Molasses provides this beneficial nutrient and many others while also regulating them.

Flush with molasses and expect a healthy cannabis root system, stronger growth, and bigger yields. Many cultivators claim it also sweetens the taste and quality of buds.


Depending on your growing environment and nutrient choice, there could be drawbacks to using molasses for cannabis. Applying the substance can have negative impacts, including:

  • Toxicity: Molasses increases pH levels in soil and water. If your grow medium already has high pH levels, introducing the substance may cause toxicity issues.
  • Unwanted visitors: If you’re growing cannabis outdoors and flush with molasses, it may attract dangerous pests and animals. The sweet smell appeals to many creatures that can damage your crop in search of sugar.

The drawbacks of molasses for cannabis are minimal, and there’s a positive consensus among most growers who use it.

Molasses flush: How & When to do it

Proper application is crucial for a plant to obtain the benefits of molasses. Understanding when to use the substance and the correct quantities to employ is essential for growers. Applying molasses in a flush cycle requires some knowledge.

Molasses flush How and When to do it

Let’s first look at the different types:

  • Light: Molasses from the first sugar boil are lighter in color and the mildest form of the substance. This type is ideal for those who prefer a gentle and organic approach to growing weed.
  • Medium or dark: The second sugar boil produces a darker brown substance. This form of molasses has a stronger flavor and more concentration of carbohydrates and potassium.
  • Unsulphured blackstrap molasses: The third sugar boil results in the darkest and most nutrient-rich form of the substance. Many growers prefer blackstrap molasses due to its high concentrations of natural chemicals.

Flushing with molasses usually involves watering cannabis without other external nutrients. The cleansing procedure benefits plants. Improved composition of soil and water drives vitality and flower development. This practice also removes excess chemicals before a harvest.

The process is helpful during the plant’s vegetative and flowering periods. Some growers alternate between weeks of supplying potent nutrients and then only water. Many cultivators flush at the end and supplement the plants using molasses before a harvest.

Here’s a simple guide for applying the substance with water:

  • Mix with water: During the vegetative stage, mix 4–5 ml of molasses per 33 fl. oz. of water. Maintain this level and apply it up to twice a week when hydrating your plants.
  • Pay close attention: When using any additional chemical or minerals, it’s crucial to watch for signs of nutrient burn. If you notice indications, reduce the dosage of sugar and other marijuana fertilizers you’re supplying to the plant.
  • Increase the quantity: When flushing cannabis with molasses during the flowering period and before harvesting, use 8–10 ml per 33 fl. oz. of water. The increase in dosage compensates for the added potassium requirements.

It’s possible to apply molasses in its dry form or as a foliar spray. The substance also provides external benefits to marijuana plants. To incorporate the syrup when flushing, large amounts of water are necessary to remove other nutrients and chemicals.

Flushing with molasses is popular among growers who cultivate using the perpetual harvest technique. The substance works wonders for regulating multiple plants and tents in various stages of growth simultaneously.

The symbiosis of molasses during flush and cannabis

Molasses is a fantastic way to enhance your cannabis plant during its development. The substance is safe, and the results can be astonishing.

Are you interested in cultivating cannabis? Flush with molasses and marvel as you yield enormous harvests of aromatic buds.

Check out our online seed store to see our premium range of high-quality products. Discover the best strains to suit your preferences, and start cultivating cannabis today.

using molasses

FAQs about flushing with molasses

Here are some frequently asked questions about flushing cannabis plants with molasses, with answers from our experts.

How does molasses affect cannabis before a harvest?

Using molasses before a harvest can significantly impact the end product. The substance provides potassium and other nutrients to cannabis during flushing. 

Molasses also helps keep the soil and roots functioning at optimal levels before you chop down your crop. The final stages of cannabis cultivation are crucial. Learning how and when to harvest marijuana with molasses can positively influence your weed’s flavor and produce greater yields.

Can I use molasses when flushing if I grow organic cannabis?

Flushing organic cannabis with molasses is popular for cultivators who prefer natural methods and supplements. The substance is an excellent source of nutrients and works with microorganisms to promote a healthy medium and root system.

Outdoor growers should consider the soil in their area. If the ground is highly acidic, adding molasses may cause pH problems. The substance provides excellent sustenance in places where the natural medium lacks potassium and other nutrients.

Wherever you cultivate, starting the right way offers the best chance at a successful harvest. Choose the optimal approach for your setup, like using indoor weed seeds with artificial lights. Begin your journey with the perfect plants and try molasses to support and enhance them.

About the Author: Kyle Kushman

Kyle Kushman is a legend in the cannabis community. He is the modern-day polymath of pot: cultivator, breeder, activist, writer, and educator. After winning no less than 13 Cannabis Cups, there’s nothing this guy doesn’t know about indoor growing - he’s been there, done it, and is still doing it to this day!

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