As plants mature and prepare to bloom, their need for carbohydrates outpaces their capacity to produce them. Molasses is useful to plants throughout their life cycle, but it is most valuable at the transition from the vegetative stage to the peak of bloom time, when the need for sugars peaks. The extra carbohydrates in molasses give plants a boost that helps them flower more abundantly than if they relied solely on self-made sugar.
Incorporating molasses into your regular feeding cycle is most effective and easiest when it’s combined with other ingredients in well-balanced liquid fertilizers. All of the nutrients in the solution are more readily absorbed when molasses is in the mix and the sugars are available exactly when plants need them most.
When your plants are two to three weeks from the end of their growing cycle, stop giving them molasses and other fertilizers and give them only water to “flush” out any unused nutrients. If you have leftover blackstrap molasses, you can mix it up at a rate of about a cup per gallon and pour it on your compost pile, where it will stimulate the good microbes at work there, too.
How Molasses Helps Your Plants Grow
When sugar cane or sugar beets are processed, the pure sucrose is extracted, leaving behind highly viscous syrup. After that fluid is boiled, it becomes what’s called “Barbados” or “mild” molasses. Very sweet and light in color, it’s used to flavor hot cereal, tea, and other foods. A second boil yields dark molasses, an amber-colored syrup that’s commonly used in cooking and baking. When boiled a third time, much of the sugar is gone and what’s left is dark, strong-flavored – almost bitter-tasting – blackstrap molasses. It is used primarily in cattle feed and it’s also a key ingredient in dark rum.
We all know that sugar isn’t the healthiest food for people, but for plants and the microorganisms that support them it is a valuable source of energy and nutrients, boosting both the quantity and quality of your harvest. We’re not talking about ordinary table sugar here, but molasses, a by-product of sugar production. Before you grab a bottle of molasses from the shelf at your supermarket and pour it on your crop, here’s what you need to know about where it comes from, how it works, and how to use it.
Molasses: What is it?
The key minerals that make molasses a healthy food for people are vital for plants, too. Potassium and calcium, in particular, play an essential role in the processes that plants go through as they form buds and flowers. Even better, the sugar works as a natural “chelating” agent, binding it to other nutrients so they are more readily absorbed by plants.
You get the most benefit from molasses in your nutrient solution in soil-based systems, though it works for hydro, too. If adding your own molasses, be sure to check the pH of the solution before giving it to your plants – the sugars will pull it toward the acidic side.
Molasses comes in several types, varying in extraction method and sweetness. Molasses extracted from sugar cane is typically made into a food flavoring or sweetener, while molasses extracted from sugar beets has a bad taste and smell and is, therefore, used primarily as an additive in animal feed.
There are two ways in which molasses benefits cannabis-plant growth.
One of the key factors for any cannabis grower who grows in soil rather than hydroponically is the quality of the soil itself. Healthy soil supportive of growing healthy cannabis plants is rich in nutrients like phosphorus and nitrogen and minerals like iron, calcium, magnesium and potassium.
What is molasses?
Molasses isn’t just for baking cookies anymore. Cannabis growers everywhere have started discovering the incredible benefits of molasses for growing better cannabis.
Known as black treacle in the UK, molasses is a dark, viscous substance produced during the process of refining sugar. First, sugar beet juice or sugar cane is boiled down into a thick syrup.
Why is molasses so beneficial to cannabis plants?
Then, once the sugar crystals are extracted to make sugar, the syrup remaining is molasses.
As cannabis plants grow, however, and they continue to feed on these nutrients, they progressively deplete these nutrients until there are none left in the soil. It is, therefore, necessary to supplement and replenish these nutrients to continue sufficiently nourishing your cannabis plants.