Worm Castings: How Worm Poop Can Make Your Soil Richer


Photo courtesy of www.ecoyardfarming.com at Flickr.com.

Healthy soil is full of worm castings. That’s the polite euphemism for worm poop – it sounds better than worm droppings or worm crap. No matter what you call this fertilizer, worm castings are a great natural way to boost the nutrient capacity of soil. Unlike cow patties or other excrement, worm castings are odor free. They’ve been reprocessed by a worms stomach multiple times, which means they’ve reached a stable, neutral state. Worms have done all the hard work of breaking down nutrients into their base components – these are simple building blocks that plants can work with easily.

Worm castings also contain several million helpful bacterium per gram. These helpful bacteria come from inside the stomach of worms. Just like the human body uses symbiotic organisms to digest food, worms also rely on the help of microscopic helpers. These bacteria remain active in vermicastings, and they will help make nutrients available to plants. Many soil bacteria help plants by converting nitrogen compounds into natural fertilizer underground. The enzymes produced by these bacteria also help break up soil debris, such as dead roots, wood chips, and clumps of earth that roots would otherwise have to waste time growing around. Worm castings have 10 to 20 times the microbial activity of topsoil where worms aren’t present.

Also, healthy soil bacteria allow plants to get more nutrients from the soil. When a plant drops a leaf onto the ground, it can take a long time for the nutrients in that leaf to break down into the soil. Soil bacteria accelerate this natural process by increasing the speed of nutrient cycling. Instead of waiting several years for the carbon, potassium, and nitrogen, plants are able to use and re-use the nutrients at a faster rate. This allows plants to grow at a much faster rate than they would otherwise.

As plants grow, they go through cycles of respiration and chemical synthesis. Each step of this process requires energy as the plants produce chemicals that they need, and that energy is not available for other life processes. A tree or flower that has to work hard to extract nutrients from the soil is more vulnerable to insect damage or disease. Active soil bacteria help make plants healthier by closing the loop and assisting in the synthesis of many amino acids, micro nutrients, and chemical precursors. They work like a surgical nurse in the hospital, passing tools along as they’re needed.

Worm castings are also great for soil structure because they retain moisture very well. Worm castings can hold 9 times their weight in moisture. This water capacity is similar to peat moss, mulch, and coconut fiber. That’s important because dry soil can harm plants by sucking the moisture out of their roots. If your soil is too dry, try mixing in some vermi compost. Since worm castings retain moisture, they can help your plants survive even in drought like conditions. When used as a soil amendment, worm castings reduce the danger of cracked foundations, erosion, and subsidence.

Photo courtesy of Zombizi at Flickr.com.

{ 2 comments… read them below or add one }

Ryan May 16, 2009 at 2:10 pm

I’ve personally found worm castings to be the best fertilizer I’ve ever used. I’ve grown monster-sized pumpkins, and a cucumber plant that wanted to consume the rest of the garden, all on worm castings.

You can’t go wrong with the natural choice.


onolina November 3, 2011 at 11:22 pm

thank u for the info and i can list all the info on my notes so I can get a good science project grade!!!!!!!


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