Molasses Manual – A Marijuana Growers Guide To Soil Sweeteners

:warning: This topic is part of the GrowFAQ series created by excellent members of Overgrow community.

Be sure to visit our homepage for latest cannabis news, discussions and galleries.

Join Overgrow and learn how to grow! :four_leaf_clover: To comment on this FAQ hit Reply button.

Sweet Organic Goodness – Magical Molasses

There are a number of different nutrient and fertilizer companies selling a variety of additives billed as carbohydrate booster products for plants. Usually retailing for tens of dollars per gallon if not tens of dollars per liter, these products usually claim to work as a carbohydrate source for plants. A variety of benefits are supposed to be unlocked by the use of these products, including the relief of plant stresses and increases in the rate of nutrient uptake. On the surface it sounds real good, and while these kinds of products almost always base their claims in enough science to sound good, reality doesn’t always live up to the hype.

The 3LB are pretty well known for our distrust of nutrient companies like Advanced Nutrients who produce large lines of products (usually with large accompanying price tags) claiming to be a series of “magic bullets” – unlocking the keys to growing success for new and experienced growers alike. One member of the three_little_birds grower’s and breeder’s collective decided to sample one of these products a while back, intending to give the product a fair trial and then report on the results to the community at Cannabis World.

Imagine, if you will, Tweetie bird flying off to the local hydroponics store, purchasing a bottle of the wonder product – “Super Plant Carb!” (not it’s real name) – and then dragging it back to the bird’s nest. With a sense of expectation our lil’ bird opens the lid, hoping to take a peek and a whiff of this new (and expensive) goodie for our wonderful plants. She is greeted with a familiar sweet smell that it takes a moment to place. Then the realization hits her. . .

Molasses! The “Super Plant Carb!” smells just like Blackstrap Molasses. At the thought that she’s just paid something like $15 for a liter of molasses, our Tweetie bird scowls. Surely she tells herself there must be more to this product than just molasses. So she dips a wing into the sweet juice ever so slightly, and brings it up to have a taste.

Much the same way a sneaky Sylvester cat is exposed by a little yellow bird saying – “I thought I saw a puddy tat . . . I did I did see a puddy tat . . . and he’s standing right there!” – our Tweetie bird had discovered the essence of this product. It was indeed nothing more than Blackstrap Molasses, a quick taste had conformed for our Tweetie bird that she had wasted her time and effort lugging home a very expensive bottle of plant food additive. Molasses is something we already use for gardening at the Bird’s Nest. In fact sweeteners like molasses have long been a part of the arsenal of common products used by organic gardeners to bring greater health to their soils and plants.

So please listen to the little yellow bird when she chirps, because our Tweetie bird knows her stuff. The fertilizer companies are like the bumbling Sylvester in many ways, but rather than picturing themselves stuffed with a little bird, they see themselves growing fat with huge profits from the wallets of unsuspecting consumers. Let us assure you it’s not the vision of yellow feathers floating in front of their stuffed mouths that led these executives in their attempt to “pounce” on the plant growing public.

And the repackaging of molasses as plant food or plant additive is not just limited to the companies selling their products in hydroponic stores. Folks shopping at places like Wal-Mart are just as likely to be taken in by this tactic. In this particular case the offending party is Schultz® Garden Safe All Purpose Liquid Plant Food 3-1-5. This is a relatively inexpensive product that seems appealing to a variety of organic gardeners. Here’s Shultz own description of their product.

“Garden Safe Liquid Plant Foods are made from plants in a patented technology that provides plants with essential nutrients for beautiful flowers and foliage and no offensive smell. Plus they improve soils by enhancing natural microbial activity. Great for all vegetables, herbs, flowers, trees, shrubs and houseplants including roses, tomatoes, fruits, and lawns. Derived from completely natural ingredients, Garden Safe All Purpose Liquid Plant Food feeds plants and invigorates soil microbial activity. Made from sugar beet roots! No offensive manure or fish odors.”

That sure sounds good, and the three_little_birds will even go as far as to say we agree 100% with all the claims made in that little blurb of ad copy. But here’s the problem, Shultz isn’t exactly telling the public that the bottle of “fertilizer” they are buying is nothing more than a waste product derived from the production of sugar. In fact, Schultz® Garden Safe 3-1-5 Liquid Plant Food is really and truly nothing more than a form molasses derived from sugar beet processing that is usually used as an animal feed sweetener. If you don’t believe a band of birds, go ahead and look for yourself at the fine print on a Garden Safe bottle where it says – “Contains 3.0% Water Soluble Nitrogen, 1.0% Available Phosphate, 5.0% Soluble Potash – derived from molasses.”

The only problem we see, is that animal feed additives shouldn’t be retailing for $7.95 a quart, and that’s the price Shultz is charging for it’s Garden Safe product. While we don’t find that quite as offensive as Advanced Nutrients selling their “CarboLoad” product for $14.00 a liter, we still know that it’s terribly overpriced for sugar processing wastes. So, just as our band of birds gave the scoop on poop in our Guano Guide, we’re now about to give folks the sweet truth about molasses.

Molasses is a syrupy, thick juice created by the processing of either sugar beets or the sugar cane plant. Depending on the definition used, Sweet Sorghum also qualifies as a molasses, although technically it’s a thickened syrup more akin to Maple Syrup than to molasses. The grade and type of molasses depends on the maturity of the sugar cane or beet and the method of extraction. The different molasses’ have names like: first molasses, second molasses, unsulphured molasses, sulphured molasses, and blackstrap molasses. For gardeners the sweet syrup can work as a carbohydrate source to feed and stimulate microorganisms. And, because molasses (average NPK 1-0-5) contains potash, sulfur, and many trace minerals, it can serve as a nutritious soil amendment. Molasses is also an excellent chelating agent.

Several grades and types of molasses are produced by sugar cane processing. First the plants are harvested and stripped of their leaves, and then the sugar cane is usually crushed or mashed to extract it’s sugary juice. Sugar manufacturing begins by boiling cane juice until it reaches the proper consistency, it is then processed to extract sugar. This first boiling and processing produces what is called first molasses, this has the highest sugar content of the molasses because relatively little sugar has been extracted from the juice. Green (unripe) sugar cane that has been treated with sulphur fumes during sugar extraction produces sulphured molasses. The juice of sun-ripened cane which has been clarified and concentrated produces unsulphured molasses. Another boiling and sugar extraction produces second molasses which has a slight bitter tinge to its taste.

Further rounds of processing and boiling yield dark colored blackstrap molasses, which is the most nutritionally valuable of the various types of molasses. It is commonly used as a sweetner in the manufacture of cattle and other animal feeds, and is even sold as a human health supplement. Any kind of molasses will work to provide benefit for soil and growing plants, but blackstrap molasses is the best choice because it contains the greatest concentration of sulfur, iron and micronutrients from the original cane material. Dry molasses is something different still. It’s not exactly just dried molasses either, it’s molasses sprayed on grain residue which acts as a “carrier”.

Molasses production is a bit different when it comes to the sugar beet. You might say “bird’s know beets” because one of our flock grew up near Canada’s “sugar beet capitol” in Alberta. Their family worked side by side with migrant workers tending the beet fields. The work consisted of weeding and thinning by hand, culling the thinner and weaker plants to leave behind the best beets. After the growing season and several hard frosts – which increase the sugar content – the beets are harvested by machines, piled on trucks and delivered to their destination.

At harvest time, a huge pile of beets will begin to build up outside of the sugar factory that will eventually dwarf the factory itself in size. Gradually throughout the winter the pile will diminish as the whole beets are ground into a mash and then cooked. The cooking serves to reduce and clarify the beet mash, releasing huge columns of stinky (but harmless) beet steam into the air. Sometimes, if the air is cold enough, the steam will fall to the ground around the factory as snow!

As we’ve already learned, in the of sugar cane the consecutive rounds of sugar manufacturing produce first molasses and second molasses. With the humble sugar beet, the intermediate syrups get names like high green and low green, it’s only the syrup left after the final stage of sugar extraction that is called molasses. After final processing, the leftover sugar beet mash is dried then combined with the thick black colored molasses to serve as fodder for cattle. Sugar beet molasses is also used to sweeten feed for horses, sheep, chickens, etc.

Sugar beet molasses is only considered useful as an animal feed additive because it has fairly high concentrations of many salts including calcium, potassium, oxalate, and chloride. Despite the fact that it’s not suitable for human consumption and some consider it to be an industrial waste or industrial by-product, molasses produced from sugar beets makes a wonderful plant fertilizer. While humans may reject beet molasses due to the various “extras” the sugar beet brings to the table, to our plant’s it’s a different story. Sugar beet molasses is usually fairly chemical free as well, at least in our experience. Although farmers generally fertilize their fields in the spring using the various arrays of available fertilizers, weed chemicals (herbicides) are not used for this crop due to the beet plant’s relatively delicate nature.

There is at least one other type of “molasses” we are aware of, and that would be sorghum molasses. It’s made from a plant known as sweet sorghum or sorghum cane in treatments somewhat similar to sugar beets and/or sugar cane processing. If our understanding is correct, sorghum molasses is more correctly called a thickened syrup rather than a by-product of sugar production. So in our eyes sorghum molasses is probably more like Maple Syrup than a true molasses.

In the distant past sorghum syrup was a common locally produced sweetener in many areas, but today it is fairly rare speciality product that could get fairly pricey compared to Molasses. Because sorghum molasses is the final product of sweet sorghum processing, and blackstrap and sugar beet molasses are simply waste by-products of sugar manufacturing, it’s pretty easy to understand the difference in expense between the products. The word from the birds is – there isn’t any apparent advantage to justify the extra expense of using sorghum molasses as a substitute for blackstrap or sugar beet molasses in the garden. So if you find sorghum molasses, instead of using it in your garden, you’ll probably want to use it as an alternate sweetener on some biscuits.

That’s a quick bird’s eye look at the differences between the various types and grades of molasses and how they are produced. Now it’s time to get a peek at the why’s and how’s of using molasses in gardening.

Why Molasses?

The reason nutrient manufacturer’s have “discovered” molasses is the simple fact that it’s a great source of carbohydrates to stimulate the growth of beneficial microorganisms. “Carbohydrate” is really just a fancy word for sugar, and molasses is the best sugar for horticultural use. Folks who have read some of our prior essays know that we are big fans of promoting and nourishing soil life, and that we attribute a good portion of our growing success to the attention we pay to building a thriving “micro-herd” to work in concert with plant roots to digest and assimilate nutrients. We really do buy into the old organic gardening adage – “Feed the soil not the plant.”

Molasses is a good, quick source of energy for the various forms of microbes and soil life in a compost pile or good living soil. As we said earlier, molasses is a carbon source that feeds the beneficial microbes that create greater natural soil fertility. But, if giving a sugar boost was the only goal, there would be lot’s of alternatives. We could even go with the old Milly Blunt story of using Coke on plants as a child, after all Coke would be a great source of sugar to feed microbes and it also contains phosphoric acid to provide phosphorus for strengthening roots and encouraging blooming. In our eyes though, the primary thing that makes molasses the best sugar for agricultural use is it’s trace minerals.

In addition to sugars, molasses contains significant amounts of potash, sulfur, and a variety of micronutrients. Because molasses is derived from plants, and because the manufacturing processes that create it remove mostly sugars, the majority of the mineral nutrients that were contained in the original sugar cane or sugar beet are still present in molasses. This is a critical factor because a balanced supply of mineral nutrients is essential for those “beneficial beasties” to survive and thrive. That’s one of the secrets we’ve discovered to really successful organic gardening, the micronutrients found in organic amendments like molasses, kelp, and alfalfa were all derived from other plant sources and are quickly and easily available to our soil and plants. This is especially important for the soil “micro-herd” of critters who depend on tiny amounts of those trace minerals as catalysts to make the enzymes that create biochemical transformations. That last sentence was our fancy way of saying – it’s actually the critters in “live soil” that break down organic fertilizers and “feed” it to our plants.

One final benefit molasses can provide to your garden is it’s ability to work as a chelating agent. That’s a scientific way of saying that molasses is one of those “magical” substances that can convert some chemical nutrients into a form that’s easily available for critters and plants. Chelated minerals can be absorbed directly and remain available and stable in the soil. Rather than spend a lot of time and effort explaining the relationships between chelates and micronutrients, we are going to quote one of our favorite sources for explaining soil for scientific laymen.

“Micronutrients occur, in cells as well as in soil, as part of large, complex organic molecules in chelated form. The word chelate (pronounced “KEE-late”) comes from the Greek word for “claw,” which indicates how a single nutrient ion is held in the center of the larger molecule. The finely balanced interactions between micronutrients are complex and not fully understood. We do know that balance is crucial; any micronutrient, when present in excessive amounts, will become a poison, and certain poisonous elements, such as chlorine are also essential micronutrients.

For this reason natural, organic sources of micronutrients are the best means of supplying them to the soil; they are present in balanced quantities and not liable to be over applied through error or ignorance. When used in naturally chelated form, excess micronutrients will be locked up and prevented from disrupting soil balance.”

Excerpted from “The Soul of Soil
by Grace Gershuny and Joe Smillie

That’s not advertising hype either, no product being sold there. That’s just the words of a pair of authors who have spent their lives studying, building, and nurturing soils.

Molasses’ ability to act as a chelate explains it’s presence in organic stimulant products like Earth Juice Catalyst. Chelates are known for their ability to unlock the potential of fertilizers, and some smart biological farmers we know are using chelating agents (like Humic Acid) to allow them to make dramatic cuts in normal levels of fertilizer application.

One way to observe this reaction at work would be to mix up a solution of one part molasses to nine parts water and then soak an object which is coated with iron rust (like a simple nail for instance) in that solution for two weeks. The chelating action of the molasses will remove the mineral elements of the rust and hold them in that “claw shaped” molecule that Grace and Joe just described.

As we’ve commented on elsewhere, it’s not always possible to find good information about the fertilizer benefits of some products that aren’t necessarily produced as plant food. But we’ve also found that by taking a careful look at nutritional information provided for products like molasses that can be consumed by humans, we can get a pretty decent look at the nutrition we can expect a plant to get as well.

There are many brand’s of molasses available, so please do not look at our use of a particular brand as an endorsement, our choice of Brer Rabbit molasses as an example is simply due to our familiarity with the product, one of our Grandmother’s preferred this brand.

Brer Rabbit Blackstrap Molasses
Nutritional Information and Nutrition Facts:

  • Serving Size: 1Tbsp. (21g).
  • Servings per Container: About 24.
  • Amount Per Serving: Calories – 60;

Percentage Daily Values;

  • Fat – 0g, 0%;
  • Sodium – 65mg. 3%;
  • Potassium – 800 mg. 23%;
  • Total Carbohydrates – 13g, 4%;
  • Sugars – 12g,
  • Protein – 1g,
  • Calcium – 2%; Iron 10%;
  • Magnesium 15%;
  • Not a significant source of calories from fat, sat.
  • fat, cholesterol, fiber, Vitamin A, and Vitamin C.

The How’s of Molasses

Undoubtedly some folks are to the point where they are ready for our flock to “cut to the chase.” All the background about molasses making and the various kinds of molasses is good, and knowing how molasses works as a fertilizer is great too, but by now many of you may be thinking – isn’t it about time to learn how to actually use this wonder product?! So this section of the “Molasses Manual” is for our birdie buds who are ready, waiting, and wanting to get going with bringing the sticky goodness of molasses into their garden.

Molasses is a fairly versatile product, it can serve as a plant food as well as a an additive to improve a fertilizer mix or tea. Dry molasses can be used as an ingredient in a fertilizer mix, and liquid molasses can be used alone or as a component in both sprays and soil drenches. Your personal preferences and growing style will help to decide how to best use this natural sweetener for it’s greatest effect in your garden.

We will try and address the use of dry molasses first, although we will openly admit this is an area where we have little actual experience with gardening use. We’ve certainly mixed dry molasses into animal feed before, so we’re not totally unfamiliar with it’s use. Folks may remember from our earlier description of the various kinds of molasses that dry molasses is actually a ground grain waste “carrier” which has been coated with molasses. This gives dry molasses a semi-granular texture that can be mixed into a feed mix (for animals) or a soil mix (for our favorite herbs). Dry molasses has a consistency that was described by one bird as similar to mouse droppings or rat turds, (folks had to know we’d fit a manure reference in here somehow).

The best use we can envision for dry molasses in the herb garden is to include it in some sort of modified “super-soil” recipe, like Vic High originally popularized for the cannabis community. As we admitted, the use of dry molasses in soil mixes isn’t something we have personal experience with, at least not yet. We are planning some experiments to see how a bit of dry molasses will work in a soil mix. We believe that moderate use should help stimulate micro-organisms and also help in chelating micronutrients and holding them available for our herbs. The plan is to begin testing with one cup of dried molasses added per 10 gallons of soil mix and then let our observations guide the efforts from there.

Another option for molasses use in the garden is it’s use alone as a fertilizer. The Schultz Garden Safe Liquid Plant Food is a perfect example of the direct application of molasses as a plant food. Garden Safe products are available from a variety of sources, including Wal-Mart. Although we consider them overpriced for a sugar beet by-product, Garden Safe products are fairly cost effective, especially compared to fertilizers obtained from a hydroponics or garden store, and they can serve as a good introduction to molasses for the urban herb gardener.

Here are the basic instructions a gardener would find on the side of a bottle of this sugar beet by-product –

Mix Garden Safe Liquid All Purpose Plant Food in water. Water plants thoroughly with solution once every 7-14 days in spring and summer, every 14-30 days in fall and winter. Indoors, use 1/2 teaspoon per quart (1 teaspoon per gallon); outdoors, 1 teaspoon per quart (4 teaspoons per gallon). 32 fluid ounces (946ml). Contains 3.0% Water Soluble Nitrogen, 1.0% Available Phosphate, 5.0% Soluble Potash derived from molasses.

In our own experience with Garden Safe Liquid fertilizers, we’ve used a pretty close equivalent to the outdoor rate on indoor herbs with some good success.

Our best application rate for Garden Safe 3-1-5 ended up being around 1 Tablespoon per gallon ( 1 Tablespoon = 3 teaspoons). Used alone it’s really not a favorite for continuos use, since we don’t see Garden Safe 3-1-5 as a balanced fertilizer. It doesn’t have enough phosphorous to sustain good root growth and flower formation in the long term. It’s best use would probably be in an outdoor soil grow where there are potential pest issues. Animal by-products like blood meal and bone meal are notorious for attracting varmints, so Garden Safe sugar beet molasses fertilizers could provide an excellent “plant based” source of Nitrogen and Potassium for a soil that’s already been heavily amended with a good slow release source of phosphorous, our choice would be soft rock phosphate.

Blackstrap molasses could also be used in a similar fashion, as a stand alone liquid fertilizer for the biological farmer who needs to avoid potential varmint problems caused by animal based products. But, we really believe there is a better overall use for molasses in the organic farmer’s arsenal of fertilizers. Our suggestion for the best available use, would be to make use of the various molasses products as a part making organic teas for watering and foliar feeding.

Since many of the folks reading this are familiar with our Guano Guide, it will come as no surprise to our audience that molasses is a product we find very useful as an ingredient in Guano and Manure teas. Most bat and seabird guanos are fairly close to being complete fertilizers, with the main exception being that they are usually short in Potassium. Molasses is turns out is a great source of that necessary Potassium. As we learned earlier, molasses also acts as a chelating agent and will help to make micronutrients in the Guano more easily available for our favorite herbs.

A good example of a guano tea recipe at the Bird’s Nest is really as simple as the following:

  • 1 Gallon of water

  • 1 TBSP of guano (for a flowering mix we’d use Jamaican or Indonesian Bat Guano – for a more general use fertilizer we would choose Peruvian Seabird Guano.)

  • 1 tsp blackstrap or sugar beet molasses

We mix the ingredients directly into the water and allow the tea mix to brew for 24 hours. It’s best to use an aquarium pump to aerate the tea, but an occasional shaking can suffice if necessary and still produce a quality tea. We will give you one hint from hard personal experience, make sure if you use the shake method that you hold the lid on securely, nobody appreciate having a crap milkshake spread over the room.

Some folks prefer to use a lady’s nylon or stocking to hold the guano and keep it from making things messy, but we figure the organic matter the manure can contribute to the soil is a good thing. Using this method we feel like we are getting the benefits of a manure tea and a guano top-dressing all together in the same application. If you prefer to use the stocking method, feel free to feed the”tea bag”leftovers to your worm or compost bin, even after a good brewing there’s lots of organic goodness left in that crap!

We also use molasses to sweeten and enrich Alfalfa meal teas. Our standard recipe for this use is:

  • 4 gallons of water

  • 1 cup of fine ground alfalfa meal

  • 1 TBSP blackstrap or sugar beet molasses

After a 24 hour brew, this 100% plant-based fertilizer is ready for application. Alfalfa is a great organic plant food, with many benefits above and beyond just the N–P-K it can contribute to a soil mix or tea. We do plan to cover Alfalfa and it’s many uses in greater detail soon in yet another thread. We prefer to mix our alfalfa meal directly into the tea, but many gardeners use the stocking”tea bag”method with great effectiveness, both work well, it’s really just a matter of personal preference.

The alfalfa tea recipe we described can be used as a soil drench, and also as a foliar feed. And foliar feeding is the final use of molasses we’d like to detail. Foliar feeding, for the unfamiliar, is simply the art of using fine mist sprays as a way to get nutrients directly to the plant through the minute pores a plant”breathes”through. It is by far the quickest and most effective way to correct nutrient deficiencies, and can be an important part of any gardener’s toolbox.

Molasses is a great ingredient in foliar feeding recipes because of it’s ability to chelate nutrients and bring them to the “table” in a form that can be directly absorbed and used by the plant. This really improves the effectiveness of foliar feeds when using them as a plant tonic. In fact it improves them enough that we usually can dilute our teas or mix them more “lean” – with less fertilizer – than we might use without the added molasses.

Of course it is possible to use molasses as a foliar feed alone, without any added guano or alfalfa. It’s primary use would be to treat plants who are deficient in Potassium, although molasses also provides significant boosts in other essential minerals such as Sulfur, Iron and Magnesium. Organic farming guides suggest application rates of between one pint and one quart per acre depending on the target plant. For growing a fast growing annual plant like cannabis, we’d suggest a recipe of 1 teaspoon molasses per gallon of water.

In all honesty, we’d probably suggest a foliar feeding with kelp concentrate as a better solution for an apparent Potassium shortage. Kelp is one of our favorite foliar feeds because it is a complete source of micronutrients in addition to being a great source of Potassium. Kelp has a variety of other characteristics that we love, and we plan that it will be the topic of it’s own detailed thread at a future date. But, for growers that cannot find kelp, or who might have problems with the potential odors a kelp foliar feeding can create, molasses can provide an excellent alternative treatment for Potassium deficient plants at an affordable price.

That looks at most of the beneficial uses of Molasses for the modern organic or biological farmer. Just when you think that’s all there could be from our beaks on the topic of molasses, that molasses and it’s sweet sticky goodness surely have been covered in their entirety, the birds chirp in to say, there is one more specialized use for molasses in the garden. Magical molasses can also help in the control of Fire Ants, and perhaps some other garden pests.

7 Likes