How to Fatten Compost Worms


Whether you're using your compost worms for fishing or selling the worms to gardeners, fat worms are most desirable. Fattened compost worms are evidence of healthy feeding and high-quality compost. You can use a variety of commercially made worm food blends to fatten up your compost worms, particularly the "worm chow" blends that are high in protein. You can also make your own worm-fattening food using a simple recipe and modifying your worms' food-scrap diet.

Step 1

Feed your compost worms lots of green vegetables. Limit starches and highly acidic fruits and vegetables.

Step 2

Place 12 egg shells into a blender. If you're using egg shells from cracked raw eggs, be sure to rinse the shells well in warm water and let them dry. Blend the egg shells until they're pulverized into a powder.

Step 3

Add 2 cups of oatmeal and 1 cup of cornmeal to the blender. Blend the cornmeal and oatmeal with the pulverized egg shells.

Step 4

Sprinkle the mixture on top of your compost until you've created a thin layer. Mist with water and cover your compost bin. If you usually leave your compost uncovered, spread a layer of moistened newspaper over the grain mixture.

Tips and Warnings

  • Don't feed your compost worms too much coffee grounds. This will raise the acidity in the compost bin and cause your worms to stay thin.

Things You'll Need

  • Green vegetable scraps
  • Blender
  • 12 egg shells
  • 1 cup cornmeal
  • 2 cups oatmeal
  • Water spray bottle
  • Newspaper (optional)


  • Worm Composting Blog: What Grains and Food to Feed Worms to Fatten Them Up

Who Can Help

  • Northwest Wigglers: Worm Food
Keywords: fatten compost worms, feed compost worms, fat composting worm

About this Author

Sarah Terry brings 10 years of experience writing novels, business-to-business newsletters, and a plethora of how-to articles. Terry has written articles and publications for a wide range of markets and subject matters, including Medicine & Health, Eli Financial, Dartnell Publications and Eli Journals.