Vermicomposting 101 (part 1):
Turning Veggie Scraps into Rich Fertilizer for your Garden
Transforming fruit and veggie scraps into plant-boosting compost may feel challenging. Composting relies on bacteria and microorganisms at constant temperatures to break down our scraps into useful material. This can be a long and stinky process if conditions aren’t right.
Enter vermicomposting, the practice of adding worms to your food scraps to produce a rich soil additive full of plant nutrients and microorganisms from worm castings. Vermicomposting allows us to upcycle food scraps, quickly returning much-needed nutrients to the land. When done correctly, red wigglers (aka: petite red worms) can quickly turn your household scraps into “nitrogen-rich” poop (worm castings) and produce an eco-friendly fertilizer for your garden without that stinky mess. Here’s how to get started:
Build Your Own Indoor Vermicompost Ecosystem
Supplies: (for a household size of 1-4 people producing scraps):
• 10-gallon size plastic container/ glass tank/ wooden box (with lid or plastic covering)
• 20-gallon plastic bag/old shower curtain for lining (if using a wooden box)
• Digital scale (to weigh your worms in the future)
• 3-4 cups potting soil
• 3 Tbsp or more of unchlorinated water
• A few stacks (~50 sheets) of black-and-white-only newsprint
• 1 pound of red wigglers
(you can order these petite red worms online if not available at your local garden store)
Setting Up Your Vermicompost Ecosystem
First and foremost, look for an indoor place that will be in the dark most of the time. Perhaps under your sink. The temperature needs to stay between 55F - 85F
Gather your supplies
Choose your bin. If you are using a plastic bin, then it is wise to drill about 10 small holes into the bottom for airflow.
4. Set up newspaper bedding in your chosen container
a. Shred newspaper into ~1” strips (cardboard can also be used if cut into small enough pieces)
b. Moisten the bedding in a bucket or your sink with non-chlorinated water, then wring out. Dump into your bin and fluff the material around
c. Add your soil to the bin
d. Gently add your worms to the bin and cover them up with a little dry newspaper and/or lid (our Colorado climate is much drier than other states, so a lid may be more user-friendly)
5. Feed your worms (place food scraps under top layer of newspaper or in the bin with a lid every 3-4 days for the first couple weeks to see how fast your worms digest it).
6. Watch for signs that your worms are happy. (Ex. If your worms are all on top and looking like they want to escape, then your ecosystem is too moist. Add more newspaper/cardboard/dry leaves/etc.)
What Can You Feed Your Worms?
Save your large yard waste (branches and large piles of leaves) for your outside compost. Although you can put a little of this carbon material into your vermicompost ecosystem when it becomes too moist, vermicomposting is a different than a backyard compost pile.
Do’s: use non-citrus fruit scraps, light amounts of citrus fruits (they take longer to break down and too much acidity could kill the worms), veggie scraps either cooked or not cooked (as long as they haven’t been cooked with oils), coffee grounds, tea bags and loose-leaf tea, eggshells, a little bit of outdoor leaves, tiny branches
Do Not’s: don’t use oils, fats, dairy products, bones (worms can’t digest)
If they are in a healthy ecosystem and fed properly, your worms will double their numbers every two months!
Stay Tuned with CFTT’s “Science on the Farm” series to find out more on managing and harvesting your worm castings.