molasses for marijuana

How to grow weed using molasses

Growing marijuana is often considered a form of art, with many who have dedicated years to perfecting and selectively breeding the weed strains that we all know and love so much today. Though beginners do have great success since most cannabis species are relatively hardy, but those with experience will tell you that feeding your plants the essential nutrients are what will result in a harvest to be truly proud of.

You could ask around to find out your friends most commonly used methods, but there are so many ways to feed cannabis plants that the answers you will receive will be inconsistent. So much so that it might even feel a little overwhelming at first. Here, we will focus on using molasses as food for growing marijuana plants including how to use it, the benefits, and how it works.

What is molasses?

Molasses typically comes in a jar and is a thick, viscous syrup that is extracted from raw sugar cane as it is refined into granulated and icing sugars. A lot of people know molasses to be a cooking ingredient that is often used to sweeten dishes, but the kind that is required for growing marijuana are organic. If you try to use an average bottle of molasses, it will contain hundreds of additives that might harm cannabis, so it is critical that garden use certified molasses be purchased for this task.

Why are molasses effective nutrients for growing marijuana?

Molasses are typically applied when growing marijuana either through daily watering or a super soil mixture. No matter which way they are given, the soils will absorb the sugars and break them down into carbohydrates which are an excellent foodfor microbes. The microbes will then consume the sugars and in turn release additional CO2 which cannabis plants love to feed off of, and require to thrive.

How to grow weed with molasses

There is a great deal of debate over the ideal way to use molasses effectively. For those who are just learning how to grow weedadministering through watering may be the most successful. Others prefer to mix molasses in combination with a super soil recipe or regular veggies plant soil.

Growing marijuana with molasses and water solution

Use either the directions located on the product or the one provided below to combine the water and molasses. This solution should only be used from the flowering stage until two weeks before harvest.

  • 2 tablespoons of molasses per gallon of water

Growing marijuana using molasses in soil

This particular recipe can be added to any vegetable safe soil three to seven days in advance of using it to plant cannabis seedlings.

  • 4 tablespoons of molasses per 1 gallon of water

The benefits of using molasses

  • Using molasses is one of the most natural and effective ways to nurture marijuana plant’s which makes it the perfect option for beginners and experienced growers alike.
  • The results of a properly administered dose of molasses on a regular basis is a healthier plant that produces bigger buds.
  • Molasses are the most cost-effective nutrient option costing an average of $5 per growing season for 6-10 cannabis plants.
  • Molasses will work well on any kind of weed strain.
  • Molasses are easily accessible and non-toxic.
  • Makes an excellent soil base.
  • Reduces mineral and vitamin nutritional issues.
  • Reduces the natural salt build up that can lead to nutritional problems.

Here, we will focus on using molasses as food for growing marijuana plants including how to use it, the benefits, and how it works.

Molasses: An Excellent Supplement For Cannabis Plants

If you want to grow cannabis the natural way, there is nothing better than molasses. Learn why molasses is excellent for growing cannabis. Find out about the many advantages of molasses for strong and healthy plants.

Molasses is often overlooked among the many nutrients and additives available to cannabis growers, yet it is one of the best supplements. Molasses isn’t just rich in valuable nutrients, but it also has the ability to improve the soil, the very foundation of your grow. In addition to that, it provides many other benefits for healthy plant growth. It helps prevent common problems when growing cannabis, for example by minimising the risk for salt build up. It even doubles as an insect repellent. Let’s have a detailed look at molasses and its benefits for cannabis cultivation.


Molasses or black treacle, as it is called in the UK, is a highly viscous, dark substance that is made during refining of sugar. It is made by boiling down sugar cane or sugar beet juice into a thick syrup. Once sugar crystals are extracted, a syrup that remains is called molasses. Different types of molasses are available, they vary in sweetness and in the way they are extracted. Molasses made from sugar cane is often made into sweeteners or used as a flavouring for foods. Sugar beet molasses, on the other hand, has an unpleasant smell and is unpalatable, so it is normally used as an animal feed additive. Not all types of molasses are suitable for growing. Some molasses of low quality can contain undesired additives, such as preservatives and chemicals that you definitely don’t want in your garden. Make sure you look for organic molasses that is suitable for gardening.


Although any type of molasses will normally contain some sulphur, some molasses made from sugar cane can have sulphur dioxide added, which is why it’s called sulphured. The sulphur dioxide acts as a preservative and an anti-microbial agent to keep the raw cane fresh until it is processed. Sulphur dioxide, however, has a side-effect that makes it unsuitable for our purpose, it also kills the beneficial microorganisms in the soil. So if you’re getting molasses for growing cannabis, make sure that it is both organic and unsulphured.

There are also different types, or “grades”, of molasses, from lighter coloured molasses that is pure sugarcane syrup, to darker molasses and then blackstrap molasses which is denser and thicker than the other types. Blackstrap molasses has undergone multiple boiling and extraction processes, so that it has the highest concentration of vitamins, micro and macro elements. It is very rich in calcium, iron, magnesium, potassium and other valuable elements.


The soil that you are using to grow your cannabis is arguably one of the most important factors for strong and healthy growth of your plants. Good soil contains nutrients such as nitrogen and phosphorus, along with minerals such as potassium, iron and calcium, as well as many other compounds and nutrients. Each of these compounds is essential for healthy growth of your cannabis plants.

But the nutritional compounds in your soil, the chemicals, minerals and other inorganic substances are not all there is to make a good environment for your plants. Soil also contains beneficial microorganisms which live in it. These microorganisms are also playing a vital role in healthy growth of your plants.

Molasses is the perfect food for these microorganisms, as it gives them the ideal environment to thrive. When you supplement soil with molasses, what you’re doing is, therefore, not so much feeding your plants, but feeding the soil and the microorganisms in it. Along with providing the microorganisms with the carbohydrates and sugars that they love to feed on, molasses also has other benefits for the soil.


  • Feeds the beneficial microorganisms in the soil
  • Improves structure and water retention of the soil
  • Enriches the soil with various essential minerals and vitamins
  • Helps to prevent the build-up of pathogens that could harm your plants
  • Helps minimise the risk for salt build-up in the soil, which could cause nutrient problems
  • Acts as a natural insecticide against common cannabis pests


What makes molasses invaluable for growing cannabis isn’t just its benefits for healthy plant growth, but also the versatility in usage. You can use it like a regular nutrient that you add to your feeding schedule, you can make composts and compost teas, use it to prepare a particularly rich soil, or apply it as a foliar spray.

How much molasses you should use, normally depends on the particular strain that you’re growing and its nutrient requirements. The right dosage can also depend on your plant’s age and may be different depending on environmental factors, such as temperatures and light intensity.

When you’re starting out feeding molasses, it is recommended that you start with lower dosages at first. A good starting point can be 4–5ml of molasses per litre of water. Later, when your plants are flowering, you can increase the dosage a bit, since your cannabis plant will need more potassium. Although you can use molasses during all stages of growth, including the vegetative phase, you will likely notice the most benefits during flowering.

The risk for overfeeding with molasses is considerably lower than with mineral nutrients, but it is smart to observe your plants for any signs of stress or nutrient burn, in particular if you add molasses to an existing feeding regimen. If things look good, you can gradually increase your dosage if needed. You can add it to organic liquid fertilizers, such as compost teas. If you’re adding molasses to your existing feeding regimen, you should also keep an eye on your soil’s pH level, since any additional substance can affect it. Make sure you check your runoff pH frequently.

If you’re growing outdoors, you should know that molasses can attract wildlife, which is something you want to keep in mind.


You can use liquid molasses as we described above, but you can also use dry molasses to enrich your soil before you start growing. Despite the name, dry molasses is actually not dried molasses, it’s made with organic bits (usually grain) that have been drenched with molasses. Dry molasses makes an excellent supplement that you can mix into your soil. You need about 500g of dry molasses to enrich about 4.5–6m² of soil.


Although there are no scientific studies about using molasses as an insecticide, it has been shown effective against sucking insects, such as aphids, white flies and lace bugs, which are among the most common cannabis pests.

You can make an effective insecticidal foliar spray by mixing approximately 1.3ml of molasses (quarter of a teaspoon) into one litre of lukewarm water. Stir well, so that the molasses dissolves. Use a garden sprayer, and liberally sprinkle your plants with the mix.


A common problem with growing cannabis can be when salt from feeding mineral, non-organic nutrients builds up in the soil over time. The accumulated salt can at some point throw off the pH level in the soil, preventing the plants from taking in nutrients any longer—the dreaded nutrient lockout. Molasses works more indirectly, as compared to mineral nutrients where you simply add nutrients every time you feed your plants. This is why using molasses doesn’t come with the same risk of salt build-up.


If you buy commercial cannabis supplements and nutrients, in particular those which are labelled organic, you will find that most of them do, in fact, contain molasses. Some “special” growth supplements may indeed be nothing more than molasses, just packed in a nice bottle.

This is not to say that these supplements wouldn’t get the job done. The advantage here is simply that molasses will cost a lot less than some fancy-brand cannabis supplements, yet will provide your plants with the same benefits. What’s more, it’s easy to buy molasses: you can get organic blackstrap molasses at most grocers and in many general stores. Also, some gardening stores stock molasses.


If you want to grow good cannabis organically, you don’t need a host of expensive nutrients and supplements. All you need is some good quality soil and molasses. Turn your soil into a rich environment with the help of molasses and your plants will thrive and reward you with aromatic buds at harvest time!

Learn about the benefits of using molasses for growing cannabis the natural way.