Facts, Research And A Little History of Molasses in Agriculture


There is a reason Molasses is a major component of Ocean Harvest, but first, a little background:

The benefits of amending soil with molasses were recognized many years ago in the sugar cane industry. It was added to soil when it was cheap and served to increase sugar cane yields. It soon became apparent that molasses provided other benefits to the crop as well as nutrition.  Much research (More, More, More…) has been done over the years on the benefits of using molasses/sugars on your plants and grasses.

Several types of molasses are widely available as liquid feed ingredients that contain at least 43% sugars. Molasses contains high levels of potassium relative to nitrogen and phosphorus as well as vitamins and trace elements, including iron.

Molasses provides so many benefits to your plants and particularly your soil. Check out this post on molasses and cannabis:


  • Stimulates the growth of beneficial micro-organisms.
    (Ocean Harvest uses 3 beneficial microorganisms)
  • Reduces damage to roots caused by root parasites during the process of decomposition.
  • Stimulates the quick microbial decay of residual organic matter.
  • Prompts the quick release of nitrogen in the soil to create short-term yield benefits.
  • Increases fruit and vegetable yields.
  • Improves environmental impact by reducing the need for nitrogen amendments and promoting more CO2-absorbing foliage growth on plants and trees.
  • Reduces plant stress by applying phytochelates to foliage.


Molasses primary function is the feeding of beneficial microbes in your soil.  These healthy microbes assist the plant in accessing nutrients in the soil, encourage the growth of healthy mycorrhizae, and they fix both nitrogen and carbon.  Molasses is also a repellent to most soft bodied insects (since they can’t digest the sugars in the molasses), it also provides a number of trace elements that assist the plant in utilizing micronutrients present in the soil.

Research done on the effects of decomposed molasses (or anaerobically digested [AD] – like Ocean Harvest contains) show high amounts of humic content and fulvic acid (a pre-cursor to humic acid – a steroid of sorts for plants).  These are the very components that make compost tea so effective in boosting plant health and growth.

A number of Ocean Harvest test growers have reported successful remediation of both caterpillar and mite infestations with a foliar application of Ocean Harvest.  (Oregon Rains makes no claims of insecticidal, fungicidal or pesticidal benefits from the use of Ocean Harvest).

What Do Gardeners Say?

  • Molasses As Fertilizer – Gardening Know How
  • Text from Dr. Elaine Ingham
    Bacteria grow well and rapidly on simple sugars to exclusion of any fungus, until sugar concentration becomes extremely high. The simple preservative effect with molasses is the high concentration of sugar. Most organisms cannot grow in the high concentration of sugar. Once a container of molasses is sealed, however, condensate can form on the under-side of the lid if the container suffers heating cooling cycles. As the water drips into the top layer of the molasses concentrate, the sugar content can be diluted enough to allow fungal or actinobacterial growth as a surface scum. Just skim off the surface scum before use in soil, compost, or tea. Do not feed to animals or humans after a surface scum has formed unless you can recognize the organism as non-harmful.

    Addition of foods that cause rapid bacterial growth can tie-up nitrate nitrogen so fast, and so effectively that plant growth can be harmed, and even stopped. Bacteria win in competition with plants for N in soil, and thus plants can be killed as the result of lack of N. Of course, the solution to this problem is NOT to kill the bacteria, but rather to establish normal nutrient cycling processes once again. How? Get the protozoa and bacterial-feeding nematodes back to work!

    Non-sulphured, Black-strap Molasses: Contains no preservative other than the high concentration of sugar. Black-strap molasses contains about 150 different kinds of sugars, from simple to somewhat complex to humics. During the extraction of sugar, heating results in condensation of the sugars into humic-like substances. The majority of foods in molasses are bacterial foods, but a few are fungal foods. Fungi tolerate high concentrations of sugar better than bacteria, so extremely high concentrations of molasses favour fungi. Testing must be performed to assess what concentration is needed to select for fungi and against bacteria in any particular set of conditions. Testing is also needed when using as a nitrate-to-bacterial biomass converter.  (This is what we use in Ocean Harvest!)

    Weed control is often STARTED with addition of molasses to tie-up the excess nitrate helping to set the stage in the soil to grow weeds, and not the plants you want to grow. Assess the calcium situation as well, however, because if you add molasses to grow lots of bacteria, and your soil has poor structure, you may just drive the soil into reduced oxygen conditions, which can result in plant death as well. As Arden Anderson says, “No number is right until all numbers are right”. Or as Elaine Ingham says, “What’s the most important organ in your body? And you can stay alive with just that one, most important item? You need all your organs, right? Soil needs all the organisms, in the right numbers and right balance and right function”. excerpt originally on 

So that gives you a little idea of the power of this simple ingredient.  Whether you use it via Ocean Harvest, or from that organic jar at the corner store, you should be using molasses on your crops, gardens and grows.


Oregon Rains proudly uses Glory Bee Organic Un-Sulphered Blackstrap Molasses in our Ocean Harvest Concentrate.