Vermicastings are the scientific term for worm castings. We feed a mixture of organic wastes to our population of earthworms (Eisenia fetida). They, in turn, ingest the material, breaking it down into smaller components, inoculating it with beneficial microbes before excreting it out their backsides. So yes, vermicastings is the fancy term for worm poop. There is no heat involved in the process, so nutrients aren't lost as gases, like they can be during composting. The earthworm greatly increases the surface area of ingested material allowing for a high density of microbes to colonize the material and increase the nutrient availability of this now stable organic matter. This method of managing organic material is called vermiculture.
Remaining fruit and vegetable waste after 5 days of feeding
Worm bin fed with shredded fruit and vegetable waste
Worm castings are water-soluble allowing plants to quickly absorb essential nutrients and trace minerals. These nutrients are available to plants over a greater length of time and will not burn even the most delicate plants. They are much richer in nutrients and beneficial microbes than bulk compost, therefore application rates are much lower. Chemical fertilizers are a one-shot wonder. The plant uses what is immediately available – the rest leaches out into the soil beyond the plants reach, providing no long term benefits. Worm castings release nutrients slowly, making them readily available to plants throughout long stretches of the growing season.
To understand why worm castings supercharge plants, we need some backstory.
It’s kind of funny, soil didn’t start out with plants. It started out with microorganisms, such as bacteria, fungi, protozoa, and nematodes. We will refer to them as microbes. Plants came after, so for the hundreds of millions of years that plants evolved in the soil, they have always had microbes alongside them. That’s a long time to get to know someone, and the plants formed a very close relationship with these microbes. It wasn’t till the last couple hundred years that we started to decouple plants from their friends via herbicides, pesticides, fungicides, grading, tilling, etc. Decoupling plants from their microbes has had its consequences.
Plants are not great at collecting water and nutrients from the soil profile on their own, so they “hire” members of the soil food web to collect many of these resources for them. These hired members are bacteria and fungi, microbes. These microbes collect resources from the surrounding soil and bring it back to the plant’s roots. The plant trades a combination of sugars, carbohydrates, and proteins called “exudates,” which it produces itself, for the resources collected by the microbes. “You give me this and I’ll give you that.” The plant gets exactly what it needs, exactly when it needs it and the microbe gets paid as well. The different organisms are simply making a mutually beneficial trade.These sorts of cooperative relationships in nature are called symbiotic relationships.Billions of these positive relationships are playing out, in the soil simultaneously, every moment of every day. Each acting as a brick, stacking one over another, constructing a landscape dominated by plants that depend on these relationships to outcompete plants with more independent growing strategies (many weed species).
The one of most important of all these cooperative relationships are between fungi and plant roots called “mycorrhiza.” 90 percent of all the plant species in the world form mycorrhizal relationships with one (frequently many) species of fungi. They play critical roles in developing and maintaining healthy ecosystems. Researchers have shown that mycorrhizas dramatically increase plant health and survival. Mycorrhiza are just one branch of the tree, which make up the history of the relationship between microbes and plants.
(mycorrhiza colonizing and extending the reach of plant root hairs)
Bacteria and fungi do more than just help plants collect vital nutrients and water. They offer many beneficial services to plants, which plants are happy to pay for. Trees for example, trees will send up to 40% of their produced energy down into the soil, in the form of exudates, to feed these microbes. Why would a tree in the fight for survival willingly give away nearly half of its energy to another organism? The tree is investing its energy into microbes and receiving a return on that energy investment that justifies nearly half of the tree’s energy production. The tree is receiving a large amount of help from these microbes!
Roots that have released exudates into their surrounding soil, commonly support populations of microbes that are 10 to 50 times higher than areas outside the root zone. This massive population of microbes depends on the plant to feed them exudates otherwise they cannot all survive. Now the survival of the microbes is directly tied to the health and survival of the plant. The plant is their source of food. It is in the best interest of the microbes to protect and support their source of food. Some of these microbes produce plant growth hormones that boost the plant’s ability to grow and function, increasing the plant’s ability to release more exudates to feed the microbes. It’s a win-win situation, the plant grows better, and the microbes get more food.
Other microbes offer protective services, deterring and out-competing organisms that would look to harm or feed on their plant buddy. For example, nematode trapping fungi contribute by preying on root feeding nematodes that look to make a meal of the plant's roots. By keeping nematode root feeding populations in check, these fungi protect the health of plant roots, ensuring better plant health and exudate production for those microbes that depend on it.
(Root feeding nematodes follow root exudates back to the plant root where they begin to feed on the root. Nematode trapping fungi mimic the roots by releasing matching exudates, attracting these harmful nematodes into the fungi’s ring traps. Once the nematode is in the trap, the cells around the ring swell up with fluid and catch the nematode in place, after which the fungi grow into the nematode and consume it.)
There are other protective microbes that colonize all of the plants roots and shoots. Providing a physical barrier between the plant and potentially harmful pests and diseases. You can think of these guys as the stone wall that surrounds a castle. The first and most important line of defense, helping to regulate who does and doesn’t get to the plant. For every disease or pest that attempts to break out in healthy soil, there is a solution to keep them irrelevant. We simply need to create and maintain the right habitat for the good guys to thrive in.
So where do all these amazing microbes live? The vast majority of them live in the topsoil. The
topsoil is where 80 percent of a plant’s roots will locate themselves. The roots concentrate here because
it is the best place to form relationships with microbes and gather nutrients. Not all soils are created
equal and when we disturb our soils with tillage, compaction, grading, synthetic fertilizers, herbicides,
and pesticides, we are killing many of the helpful microbes that our plants depend on. This reduces soil
functionality and the availability of services plants depend on, effectively turning soil into dirt. When we
disturb the soil, it is like rewinding a movie. We are sending soil backwards in time, towards conditions
that normally don’t favor the plants we are wanting to grow.
Let’s dive into soil succession a little deeper. Let’s use the example of a new neighborhood. In
the beginning, a development crew comes in and removes the vegetation and topsoil. In the Fort Wayne area 12-18 inches of topsoil is typically removed to reach subsoil, then it is graded and compacted for solid building foundations and directing stormwater movement through the neighborhood. Streets and new homes are built, then landscaping and yards are installed over the compacted subsoil. With the removal of the topsoil, the soil community has been totally reset erasing all plant services with it. This puts us back to the beginning of succession, where we will begin our journey.
Very Early Succession
Bacteria: Fungi Ratio 10000:1
There is no soil, fungi, or other important microbe groups present. Sand, silt, clay, rock are the only components present in the beginning. Bacteria that use the sun to make energy, much like plants, are the first on the scene to colonize this soil. After many cycles of life, reproduction, and death there is enough dead organic matter in the soil for the first bacterial decomposer community to move in. Eventually organic matter and soil biology builds to a point where plants can grow, usually grasses and weeds. These plant’s strategy is to produce as much seed as quickly as possible, investing minimally into roots and soil. They make up most of the 10% of plants that DO NOT form mycorrhizal relationships and do not release exudates. (This is the point in succession where we attempt many of our planting projects)
Early Succession
Bacteria: Fungi Ratio 10:1
The first exudate producing plants begin to get a foothold. Coupled with annual dieback of roots and shoots from the weeds, more organic matter and complex foods entering the system allow the first fungi to appear on the scene. The grazing and death of the bacteria in this early succession soil produces nitrogen in the form of nitrate. All plants need nitrogen, but not all plants flourish on nitrate as a source of nitrogen. Grasses, weeds, and annuals prefer nitrate. Most perennial and woody plants do not thrive on nitrate, though they may begrudgingly survive on it. Therefore, these bacteria-adapted plants that prefer nitrate more easily out-compete the perennial and woody plants. The pH of this bacterial dominate soil is also very alkaline.
Midsuccession
Bacteria: Fungi Ratio 1:1
Over time, annual weeds struggle to germinate as the soil conditions favor them less and less.
More fungal foods are added to the system via annual plant dieback. The soil community evolves and succession moves forward, this is when shrubs and other perennials start to get a foothold. Providing woody organics and releasing their own special exudates, promote more fungal growth in the soil, changing the characteristics of the soil and releasing more nitrogen in the form of ammonium instead of just nitrate. This balance of fungi:bacteria brings the soil pH towards neutral. Together, it creates soil conditions that further favor later succession plants. These later succession plants invest more energy into roots and improving their soil habitat than their weedy counterparts.
Late Succession
Bacteria: Fungi Ratio 1:2
As time passes, perennial plants, shrubs, and trees shade out early succession plants and drop their litter, continuing to promote fungal communities. In this now fungal dominate soil, pH is more on the acidic side. Nitrogen in the form of ammonium is now the most prevalent, a form that woody plants and most perennials can now thrive on, while earlier succession plants begrudgingly survive on.
Very Late Succession
Bacteria: Fungi Ratio 1:10
With a fungi: bacteria ratio now strongly in favor of woody species, late succession trees can
establish and out-compete plant species that prefer earlier succession soil conditions, continuing to move the fungi: bacteria ratio more towards fungal dominate. Old-growth forest in the pacific northwest can have fungi: bacteria ratios of 1000:1!
Most of the plants that we love in our landscaping and gardens prefer Midsuccession to late-succession soil conditions, yet we insist on planting them in very early succession soils and then wonder why they struggle so much.
(Our plants want to grow in soil on the left but we often plant in soils like the one on the right.)
It takes decades even centuries for succession to naturally play out in a soil! We don’t have that kind of time. This is where our worm castings come in. Our worm castings contain the key components of later succession soils that our desirable plants crave because at Back to Earth, we aren’t worm farmers, we’re microbe farmers. Our recipe is designed to promote massive populations of microbes at a Bacteria: Fungi Ratio that many of our desirable plants prefer. Our recipe also focuses on combating nutrient deficiencies commonly found in our heavily disturbed local soils. When we plant later succession plants in alien, early succession soil our product brings the comforts of their late succession home to them. Creating a happy microhabitat where each plant needs it. Microbes are valuable members of the soil food web and provide so many benefits to the soil and to plants.
The Ohio State University tested the effects of worm castings on bell peppers at different concentrations in Metro Mix 360 growth media (MM360). MM360 is a very common growth media in commercial greenhouses. They found that a potting mixture of 40% worm castings and 60% MM360 growth media yielded 45% higher pepper weights and had 17% greater numbers of peppers per plant, on average, than those grown in 100% MM360. Wow, that is a big difference in yield! They found significant increases in pepper weight and number in just 10% worm castings and 90% MM360 as well. A little bit can go a long way! Similar studies have been done on all sorts of different plants.
It is no wonder than the utilization of worm castings has increased rapidly in the horticultural industry since the publication of multiple studies that have measured these benefits provided by worm castings. Growers are seeing much greater economic returns, due to faster and more successful germination, earlier flowering, larger yields, and better-quality crops.
We have done some experimenting with our own worm castings. The good folks at BroxonBerry Farms in Markle, IN became hooked after our worm castings turned their germination success rate of 75% into 96% for many of their leafy greens. They were kind enough to do a growth experiment with lettuces. Comparing the lettuce head weights of lettuces grown in 5 different soils, with and without our worm castings.
“Overall, it can be determined vermicastings improved growth in the lettuces. Only one variety of the five performed worse than with vermicastings, with only a mere 1.35% difference. Since the conclusion of the trial, all lettuce starting soil on the farm has been prepared with compost and vermicastings. I have theorized the lettuce starts are developing larger root systems early on, which allow for more explosive growth in its later stages. If this theory holds true, it stands to reason vermicastings is a viable option for many plant starts to get well established early on for better late-stage growth and potentially larger harvests.”
-This trial was performed by Justin Miller on the BroxonBerry farm using Back to Earth Vermicastings
Cat grass and mystery plant grown from seed, with and without worm castings.
Variety of flowers transplanted into a blend of 30% BTE worm castings 70% potting soil, 28 days between images.
Disclaimer:All these application rates are based off science, research, and good old experience. If you don’t use them at the recommended rates, it will not be the end of the world. You can see significant results at lower rates. A little can go a long way, so don’t be afraid to experiment.
Remember, the more contact your plant's roots have with the castings, the stronger your results will be. We do not recommend ever planting in 100% vermicastings. A high-quality vermicast contains natural plant growth hormones, which can harm plants if the levels are too high. There really is such a thing as too much of a good thing. Any company that claims that you should plant in 100% vermicastings is either selling a poor-quality worm casting, trying to boost their sales, or both!
TRANSPLANTING:
TREES and SHRUBS:
For Ball n Burlap Transplants follow the two illustrations below. For all other tree and shurb transplanting types, dig your transplant hole double the root ball diameter. Place transplant into the hole and mix worm castings in with the native backfill material (10-20% worm castings, 80-90% native backfill). Apply an additional layer of worm castings 1 inch deep on top of the transplant root ball extending out to the edge of the transplant hole. Then apply mulch like you normally would, but 1 inch thinner to account for the 1 inch of worm castings you applied. Water like you would a normal transplant.
FLOWERS:
Apply a thin layer of vermicastings (1 inch deep) at the bottom of the hole before planting. Place transplant into the hole, backfill the hole with a mix of worm castings (≈25%) and excavated soil (≈75%). Apply an additional layer of worm castings (1/2 inch deep) on top of the root ball before the final covering with excavated soil, like you would a normal transplant. Water often and well, but do not overwater.
FRUITS AND VEGETABLES:
Studies have shown that there are significant increases in health and yield at lower concentrations of worm castings, down to about 10% worm castings to 90% your favorite growth media. We believe the most cost-effective ratio is around a concentration of 15-20% worm castings. For best results, most common fruits and vegetables produce their maximum yield at 35%-40% worm castings 60%-65% your favorite growth media.
CUSTOM MIX:
If you are making your own potting mix from scratch, we recommend mixing 1 part vermicastings with 2 parts your favorite growth media.
ESTABLISHED PLANTS:
Scratch away the soil above the rootzone of your plant as deep as you can without disturbing the root system, apply a thin layer of worm castings directly to the bottom, then mix worm castings with the backfill you scratched away at a ratio of 1 part worm castings to 3 parts backfill. Reapply the new, mixed backfill above the rootzone, lightly pack and water.
LAWNS:
If seeding a new lawn, put on about 10 lbs. of worm castings per 100 sq. ft. of lawn. Work it into the top few inches of topsoil before spreading grass seed. After your grass seed is down, cover with straw and water. If you have an established lawn, use 8 lbs. per 100 sq. ft. of lawn as a top dressing the day before your next lawn mowing. For either new or old lawns, make sure to water well once after application. This will lead to a greener and lusher lawn that is more resilient to drought than your neighbors’.
Darker grass areas in the picture represent the areas that received heavy application of vermicastings.
VERMICAST TEA:
Vermicast tea is basically a liquid version of vermicastings. Because many of the nutrients and natural plant growth hormones are water-soluble, and a large portion of the microbes can live in water, you’ll see many of the benefits of solid vermicastings in a liquid version. Vermicast tea can easily be applied directly to your plants’ foliage via a backpack sprayer. Studies have shown that vermicast teas are effective at kickstarting seed germination and early growth stages. They also deter many pests that would very much like to damage your plants; common pests like aphids, two-spotted spider mites, and others.
Having problems with pests on your fruit trees? Doss them in a coat of vermicast tea and prevent future damage while maintaining safe, chemical-free fruits for you and your family to enjoy!
Before
Aphid investastion before Vermicast Tea applications.
After
Aphid investastion after 3 Vermicast Tea applications in 5 days.
MAKING VERMICAST TEA:
Making vermicast tea is incredibly easy. Put vermicastings in a mesh bag and soak it in a bucket with either air stones or a little aquarium air pump for 24 hours. Pour the tea into a clean backpack sprayer or squirt bottle and – BAM! – you have a liquid version of vermicastings ready to apply directly to your plants. For best results, use air stones or an air pump. These methods agitate the water and add oxygen to it, which is important for your microbe populations.
Air pumps are available on Amazon for as little at $7.00.
Mesh bags are available on Amazon for as little as $3.00 (Camco 51031 19”x22” Nylon Mesh Bag).
Best plant responses have been observed when using a ratio of vermicastings to water of between 1:10 and 1:20. To get a ratio of 1:10 use 1 ½ cup vermicastings for every one gallon of water and for a ratio of 1:20 use ¾ cup of vermicastings for every one gallon of water.
Spray early in the day before it gets too hot, and if possible, spray on cloudy days to reduce microbe exposure to UV rays.
Sale Locations:
Fort Wayne Trees
7195 East State Road 14
Columbia City, IN 46725
Broxenberry Farm
5359 W 700 N
Markle, IN 46770
Young's Greenhouse
5867 Lake Ave
Fort Wayne, IN 46815
Ruby Moon Floral
7535 E 400 S
Laotto, IN 46763
Jenny Lou’s Greenery
223 W Maumee St
Angola, IN 46703
Circle City Trees
10795 E 300 S
Zionsville, IN 46077
The Flourish Flat
1519 Main St
Genoa, OH 43430
