A Gardener’s Best Friend

11/18/2024
By: Susan Hadacek and Izzy Sonnet

You’ve probably heard the saying, “The gardener’s best friend is the worm,” and have  welcomed the sight of these small creatures wiggling around in the soil after a rain. Worms are more than just a sign of a good rainfall. Worms and the castings that they leave behind, called vermicast, have an incredibly positive impact on soil that cannot be replicated by any human-made method. Vermicast, when used as an amendment to any garden bed, can help  reduce pests, increase water retention in the soil, and expand biodiversity in the microbial community. All of these gains can enhance the flavor and nutritional value of food grown in that soil. At TomKat Ranch, we have been using vermicast to improve our soil for the past five years in our gardens, with time-tested results. 

There are around 9 thousand different species of earthworms in the world. In the vermiculture world, the Eisenia Fetida, commonly known as red wiggler, is a surface dweller most widely used for composting and the creation of castings. They eat the microbes from the decay processes of living organisms, digging and aerating the soil while recycling organic waste. This process of cultivating worms, which is called vermiculture, can be used to break down organic matter– including manure, cardboard, crop residue, food scraps, and yard debris– into vermicast, the worm waste left behind. Vermicomposting is the process of adding worms into compost after it has been heated and is in a cooling phase. 

One benefit to vermicomposting is that it can take 30 to 90 days– depending on the number of worms and type of system– compared to the 6 months to 1 year required in conventional composting. Additionally, in conventional composting aeration occurs through frequent turnings, which disrupts or destroys the microbial community. In vermiculture, the worms aerate the soil themselves so the microbial community stays intact.

There are many methods of vermiculture including the use of bins, windrows, trenches, wedge systems, and flow-through systems often seen in commercial-grade operations. When we started vermicomposting at TomKat Ranch, we began with a windrow system. The windrow system begins by creating a pile of organic bedding material, mulched leaves and garden waste, adding worms, and then layering organic materials to feed worms. Over time, we supplied more compost material, creating more food for the worms, and thus more movement as they followed the newly added organic material. 

Starting this year, we created a wedge system to produce vermicast. The wedge system is a modified windrow where food is added to the side at a 45-degree angle, allowing worms to migrate towards the fresher food and leave behind finished compost. Placing the wedge on concrete and under shelter has decreased the  chance of worms moving out of the pile while providing shade and protection from winter rains. Both of these methods, window and wedge systems, are low-tech, easy to maintain, and can be accomplished on large or small scales.   

With over 15 horses on the ranch, we have begun using a separate aerated composting system (Aerated Composting in a NutShell) to speed up the composting of horse manure mixed with garden waste. Once the initial heating-up stage is complete, usually within the first week, the partially composted material is perfect for feeding worms in the worm wedge. Within 60 to 90 days the composting process is complete. As we make compost, we are also making worm food to produce the finer, high microbial vermicast. The results we’ve seen in our gardens have been remarkable; stronger plant growth, improved soil structure, and increased crop yields. Our experience at TomKat Ranch demonstrates that integrating vermiculture into agricultural practices not only creates a sustainable waste management system but also contributes to the overall health and productivity of our gardens. We look forward to continuing to refine our methods and share our knowledge with other farmers and gardeners who are interested in harnessing the power of these remarkable creatures.