Comparing Plant Probiotics

The plant microbiome – the collection of microbes living in and around it – is extensive, not only in terms of the types, genera & species of microbes, but in terms of volume, as well. It is estimated that there are over 300,000 different species involved, with as many as 10-million microbes per cubic centimeter.

Some of those are naturally beneficial, while others are pathogenic. It is that latter group that we seek to control, if not eliminate, and the preferred way to do that is through regular inoculation with probiotics.

Each microbial species has its own secretions and exudates. Some of those kill pathogens, and others break them down, releasing their nutrients. Some secrete antibiotics that help prevent future infections, while still others stimulate plant growth by secreting hormones, by producing fuel through photosynthesis, or create food through nitrogen fixation.

Plant probiotics can exist of a single species or many, each having it’s own “niche” in the array of benefits. The bottom line is this: the more diverse the population, the broader the spectrum of effects.

Two of the most effective plant probiotics in the marketplace are Ecological Laboratories’ Quantum-Total and Concentric Ag’s Inocucor Garden Solution. Let’s look at what they contain:

Quantum-Total is packed under a hydrogen sulfide “blanket”, rendering it inert until applied, so has a long shelf-life (3 years) and can be stored at room temperature. Inocucor Garden Solution is active as-delivered, so has a shorter shelf-life and must be stored cool.

You’ll note both overlaps and differences between the two. That is bound to mean that they will have different effects on our plants, but in my years of experience with both, I cannot simply come out and recommend one over the other. Both are excellent at preventing rots of all sorts, and both provide support for-, and the stimulation of growth.

A word about probiotic labeling: Being that these products are registered as plant and soil amendments, labeling requirements are less stringent than what folks might expect. Manufacturers are not required to list the complete contents on the label, only those ingredients that they test-for and guarantee. Because the specific requirements vary from state-to-state, many manufacturers have chosen to only list the “least common denominator” of ingredients that meet the labeling requirements across the board. In other words, the product labels should be considered to be an indication of the bare minimum contents, not the total.

Inocucor Garden Solution contains both bacteria and a fungus (yeast), with the latter potentially “funneling” more water and nutrition from the pot environment into the plant, while Quantum-Total contains both nitrogen-fixing and photosynthetic bacteria, which produce food and fuel right within the plant.