If you think harvesting compost from a worm bin or compost pile and spreading it in your garden is too much work, then build yourself a worm tower!
In this article, you will learn how to use earthworms in your garden to compost right where you want the finished compost to be. The major benefit to this composting technique is that once it is set up, you don’t have to do anything but continue to add food scraps in small amounts. No turning the pile like you have to do in Hot Compost Pile Composting, and no separating the worms from the castings like you have to do in a vermicomposting bin.
The earthworm composting tower is a self spreading composting system.
It relies on the natural ability of nightcrawler earthworms to tunnel around in your garden soil eating organic material (kitchen food scraps) and depositing castings (worm poop) throughout your garden. The worm castings are very high in nutrient value and act as an organic fertilizer for any plants that you are trying to grow.
How to Build an Earthworm Composting Tower for your Garden
- Build a tower roughly 2 feet tall. In the photos, you can see that I built mine out of wood in a rectangle shape. You can also use a very large diameter PVC pipe. The PVC pipe version is easier and you can purchase a lid that fits exactly the pipe’s diameter.
- Drill many ½ inch (or so) holes in the bottom 6 inches of the pipe or wooden composting tower. This bottom portion will eventually be buried under ground and will allow hungry nightcrawlers and other earthworms to enter the composting tower, eat some veggie food scraps, and then leave to spread the castings in the rest of your garden.
- Bury the tower eight inches deep in your garden so that dirt covers all of the holes you just drilled. Worms will go in and out the open bottom of the tower and the holes you drilled. I have had success placing the tower very close to my vegetable plants. The vegetables or flowers you are growing will benefit from the added nutrients in the worm castings.
- Fill the composting tower with vegetable food scraps from your kitchen. Be sure not to put meat or bones in as those take much longer to decompose and can attract pests. You can fill your tower all the way to the top or start by filling it half way and see how long it takes the worms in your garden to eat it. Put a handful of leaves or other brown carbon compost material on top of the food scraps to deter bugs. When the level of food scraps drops, simply add more. You will be amazed how fast the food scraps in your tower disappear!
- Add a lid or top to your composting tower. I made one out of wood for my tower but if you are building your tower out of PVC pipe you can simply buy a lid that fits.
- Add Earthworms to your tower. This step is optional. The earthworms in your garden will find the food scraps on their own but if you want to kickstart the process you can always go to a local hardware or bait/tackle store and buy some nightcrawlers to put in.
- Build More! Depending on your garden’s size, you can build several of these around your garden. The more you put in your garden, the more beneficial nutrients you are adding to your soil.
Have fun building your earthworm composting tower and composting your vegetable kitchen scraps directly in your flower or vegetable garden.