Worm Castings vs. Compost: Which One Should You Use?
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By Food-Landscaping
Whether you're growing food on a balcony or building a full edible landscape, soil health is everything. And when it comes to enriching your garden beds, two organic options often come up: worm castings and compost. Both are beloved by gardeners for boosting fertility, but how do they actually compare?
Let’s dig into the differences, benefits, and best uses of each—plus a look at a fun experiment we’ve just started to test them side by side.
🪱 What Are Worm Castings?
Worm castings, also called vermicast or worm poop, are the result of worms digesting organic material. What comes out the other end is a fine, dark, soil-like substance packed with nutrients, beneficial microbes, and plant-growth hormones.
They’re often called “black gold” because of how powerful they are in small amounts. Just a handful added to a planting hole can kickstart root development, increase water retention, and help suppress disease.
Pros of Worm Castings
✅ Highly concentrated nutrients
✅ Gentle, won’t burn plant roots
✅ Packed with beneficial microbes
✅ Improves soil structure and water retention
✅ Great for seedlings and transplanting
Cons of Worm Castings
❌ Slower to produce (unless you have a worm farm)
❌ Limited quantity unless harvested yourself
❌ Can be expensive if buying in bulk
Beginner Tip: You don’t need a worm farm or a shop to get started—nature already makes worm castings for free. Just check under damp soil, mulch, or fallen leaves in your garden. Those little black pellets? That’s vermicast—scoop some up and sprinkle it around your plants or mix it into your pots. No need to spend a penny!
🌿 What Is Compost?
Compost is decomposed organic matter, often made from a mix of kitchen scraps, garden waste, leaves, grass clippings, and other biodegradable material. It’s less concentrated than worm castings, but great for building long-term soil health.
Compost adds bulk organic matter, improves soil texture, and helps feed soil microbes over time. It’s more widely available, especially if you’re composting at home.
Pros of Compost
✅ Easy to make from food and garden waste
✅ Available in large quantities
✅ Builds soil structure and moisture retention
✅ Supports beneficial soil life
Cons of Compost
❌ Nutrient levels vary depending on what goes in
❌ May not be fully broken down if rushed
❌ Not as fast-acting as worm castings
Beginner Tip: If making compost at home, avoid adding meat, dairy, or oily food scraps—they slow decomposition and attract pests. Stick to veg peelings, coffee grounds, and garden clippings.
🧪 Side-by-Side: The Smiley Strawberry Experiment
So, which one is actually better?
To find out, I set up a simple side-by-side test using two identical buckets, each planted with strawberries. One bucket is enriched with worm castings, the other with regular compost. Everything else—soil, plant variety, watering schedule—is exactly the same.
By the end of spring, we’ll see which bucket grows the happiest “hair” on our smiley strawberry heads.
🎥 Watch the full setup here: Worm Castings vs. Compost – Which One Wins?
We'll be comparing:
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🌱 Growth rate
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🌸 Flowering & fruiting
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💧 Water retention
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🐛 Pest resistance
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🍓 And, of course, final fruit quality & taste
I’ve seen worm castings boost plant growth in the past—but this time, it’s a true side-by-side experiment.
🥇 Which One Should You Use?
The honest answer? Both have their place.
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Use worm castings when you want a quick boost—especially for seedlings, potted plants, or transplanting.
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Use compost when you’re improving larger areas of soil, building up garden beds, or mulching over the season.
Many gardeners (myself included) aim to use both when possible: compost for structure, worm castings for performance.
💬 Final Thoughts
If you're gardening on a budget—or just love the idea of getting more from nature—start by foraging for worm castings right in your own garden. And if you’ve got the space, composting your kitchen scraps is one of the simplest ways to grow food while reducing waste.
👉 Curious to see which one wins in real time?
📺 Watch my experiment on YouTube and follow along as we track growth, yield, and health from both types of soil boosters.
Whether you’re team worm, team compost, or happily using both—you’re building a better garden, naturally.
Happy planting! 🌿
— Food-Landscaping