Choosing which products to use can be a daunting task. They all look so interesting, and many of them seem to be fairly similar. If you've read my product recipes article, you'll have seen that I use them all, because they all bring distinct and incredible benefits (that's why I sell them), but I'd like to summarize here the key differences between them for those who want to start with just a couple of products.
The 3 microbial products are:
- Effective microorganisms (EM)
- Compost tea
- Mycorrhizal fungi
The main confusion for most people is the difference between EM and compost tea.
Effective Microorganisms are cultured in a lab under controlled conditions, therefore it is an inoculant made up of a specific set of just a handful of species of very important microorganisms. Theses microbes are mainly fermenting microbes, such as lactic acid bacteria (as in yogurt) and yeast (as in bread, beer, and wine). They can thrive in environments with regular oxygen levels or with lower oxygen levels. They metabolize and break things down differently than most microbes. Some of the microbes in there can even take toxins and turn them into nutrients. You can buy this product all ready to use or you can ferment the mother culture into 20 times more than the original amount, much like yogurt. This process takes at least a couple of weeks, preferably a month.
Compost tea, on the other hand, is a mixture of a huge array of mostly aerobic microbes (they need oxygen) extracted from a very small amount of high quality compost. It's not as controlled of a product (not made in a lab), but it is much more diverse. Whereas EM might have 5-20 species of microbes that are specifically included (there can actually be quite a few "wild" microbes that are allowed in - over 100 - but they are not the main focus), compost tea will hopefully have thousands. This process takes 12 hours to a couple of days.
That's just a brief description of the differences between the two. For our purposes, both products provide a lot of the same benefits, albeit sometimes through different biological processes. You can start by trying out either, and eventually you may want to use both.
Mycorrhizal fungi are a very specific class of fungi that wrap around and penetrate plant roots and form a relationship whereby both the fungi and the plants benefit. They are incredibly important for plant health and are believed to have been critical in the evolution of trees. They do a lot of things, but are often specifically credited with bringing water, phosphorus, and other trace minerals to the plant in exchange for sugar, in addition to helping to protect the plant from root-feeding microbes. They can be purchased as a powder and should be applied directly to the roots or seed or in the planting hole whenever you are planting. Every time! They can also be watered into porous soils, and are often used after aeration of turf.
The 5 biostimulants are:
- sea minerals
- liquid kelp
- liquid fish hydrolysate
- humic acids
- organic blackstrap molasses
The first 3 particularly appear very similar, and I suppose they are in some ways. Here's the basics.
Sea minerals is very concentrated, mineral-rich ocean water from deep in the Pacific Ocean. It is so incredibly full of nutrients and life that it is the most incredible broad-spectrum product to spray directly on your plants and soil. There has been a lot of research and the benefits are unbelievable. This is often my first choice for a biostimulant.
Liquid kelp is different. It has many of the same nutrients, but we use it for its natural plant growth hormones that stimulate many processes in plants. We only apply 20ml/1000sqft, so although the nutrients are beneficial, it's really all about the hormones. Regular applications improve so many aspects of plant growth.
Liquid fish hydrolysate brings in more nutrients like the sea minerals, but it is particularly high in nitrogen and available phosphorus and potassium. It also has whole proteins and enzymes. It has been mixed with kelp for many decades, as they compliment each other very well. The slight smell is definitely worth it. This is particularly nice when you don't have enough humus in your soil, but it is beneficial regardless.
Humic acids are used in such tiny amounts that a pound will last a long, long time. They help the plant absorb the above products. They should always be included in a foliar spray. They can also be applied to the soil for many benefits.
Blackstrap molasses provides some nutrients, but is mostly just a great carbohydrate source, which is food for the microbes. It's great to apply with the microorganism products because it gives them instant food to begin working with. It also is sticky and helps everything stick to the plant leaves. The pros use some kind of sugar source in every foliar spray, and this is one of the best. Molasses is also used in the fermentation process to make EM, and in brewing compost tea.
So yes, I use them all, but if you're looking to choose, I hope this at least provides some clarification.