News from the Edible Demo Garden

August 2024: Worms – The Architects of the Underworld

Worms create tunnels through the soil. These tunnels provide space for air and rain to more easily penetrate through the soil to the roots of plants. Just as we need oxygen to breathe, worms breathe oxygen that dissolves into their moist skin. Worms are long and thin so there is plenty of moist skin absorbing oxygen from air percolating the soil.

When soil is turned over any exposed worms quickly wriggle underground since exposure to light would dry out their skin and without moisture, they cannot access oxygen and will die. This is also why worms prefer moist damp soil. In a drought, worms burrow deep into the soil to find moisture. When it rains heavily saturating the ground, worms need to find shelter above ground, hiding under leaves or other debris so they don't dry out. This is why after it has rained hard, birds poke around in fallen leaves, tossing them this way and that as they hunt for tasty worms. You may not like to touch, let alone eat worms, but birds love them.

When we eat, our body absorbs nutrients as our food travels through our gut. Worms are the same. They also absorb nutrients from what they eat passing through their gut. A worm is like a long pipe with a central tube through it. Worms seek vegetable matter in the soil they ingest that travels through their lip as worms move, they take in soil through their lip into their esophagus. In their gizzard, the mix of soil and vegetable matter is ground up and mixed with enzymes releasing nutrients that are absorbed as food as it travels through their intestine. Just like us, not all the nutrients we eat are absorbed. The remaining nutrients in worm poop are ideal plant food for plants whose roots absorb them.

Gardeners who build compost piles provide a smorgasbord of food for worms. Worms live about a month and multiply frequently where there is plenty of food, so compost becomes a rich source of nutrients that plant roots can absorb. Note: worm poop is typically sold as “worm casts.”

If you build a compost pile, remember just as you and I have favorite and disliked foods, so do worms. They dislike the citrus or onion families but love juicy fruits and chopped up green veggies. I once threw a few left-over radishes in my compost, only to discover months later, the same red radish as completely unblemished as the day I had discarded them.

Build Your Own Worm Bin

Raising your own vermicomposting worms can be an interesting hobby with earth-friendly gardening benefits. Learn how to create a habitat for worms at a hands-on workshop at Indian Valley College from 10 am to 12 pm on August 10, 2024. Look for “Build Your Own Worm Bin” listed under upcoming events on this website for more details and registration information.

Additional instructions can be found on the Marin Master Gardeners YouTube channel.