Worm bedding is the foundational material added to a worm habitat that provides a safe, comfortable environment for worms to live, eat, and reproduce. Ideal bedding should be lightweight, airy, and less dense than the soil or clay typically found in nature. Since you’re raising worms outside of their native environment, it’s essential to create a habitat that mimics natural conditions—offering softness, breathability, and moisture retention.
The best worm bedding materials are non-toxic, resist compacting, and allow worms to crawl freely. They should also retain moisture well and be easy for you to manage and replace. Common worm bedding materials include coconut coir, shredded paper or cardboard, sphagnum peat moss, and aged manure. Below, we’ll explore the benefits and drawbacks of each.
Coconut Coir
Pros:
Excellent water retention
Lightweight and easy for worms to burrow
Environmentally sustainable
Cons:
May be hard to source locally in bulk
Coconut coir, also known simply as coir, is a natural by-product of coconut harvesting. Extracted from the fibrous layer between the coconut shell and husk, coir is soaked and dried for over a year before use. It’s widely used in horticulture thanks to its superb moisture retention and aeration properties, making it ideal for worm bedding.
Unlike sphagnum peat moss, coir has a neutral pH of 7.0, eliminating the need to add calcium carbonate to balance acidity. It’s also more sustainable, as coconut trees continuously produce fruit. Coir is available in compressed blocks at most garden centers or online. Just soak it in water to rehydrate before use.
The only drawback is cost—coir can be more expensive than other bedding types, but availability and affordability are improving.
Shredded Paper and Cardboard
Pros:
Readily available and low-cost
Good moisture retention and airflow
Provides a secondary food source
Cons:
Can make worm harvesting difficult if not fully composted
Bulk supply may be hard to find locally
Newspaper and brown corrugated cardboard are top choices for paper-based worm bedding. Newspaper is easy to shred and widely available, while cardboard—now common thanks to online shopping—can be cut into strips with scissors or a box cutter. Mechanical shredders are also available if you want to speed up the process.
Shredded paper creates air pockets that allow oxygen flow and prevent anaerobic (oxygen-deprived) conditions that can harm worms. It also holds moisture well and becomes food as it starts to decompose and attract fungi, which worms love to eat.
Avoid white printer paper or glossy junk mail—they’re harder to break down and can clump when wet. Shredded paper can be mixed with coir, peat moss, or manure for added volume and variety.
Sphagnum Peat Moss
Pros:
Outstanding water retention
Lightweight and easy for worms to tunnel
Available at most garden centers
Cons:
May be acidic
Not considered environmentally sustainable
Peat moss, harvested from peat bogs over centuries, is a lightweight and absorbent material perfect for worm bedding. It’s easy for worms to navigate and doesn’t pose health risks. While peat moss has no nutritional value, it is commonly used due to its availability and performance.
Peat moss tends to be acidic, but you can neutralize the pH by adding calcium carbonate or soaking it in water for 24 hours. Use a pH meter to check acidity before introducing worms. Though widely used, peat moss is not a renewable resource, raising sustainability concerns.
Aged Manure
Pros:
High in nutrients
Excellent moisture retention
Cost-effective and sustainable
Cons:
Not always easy to find in urban areas
May contain residual de-worming medication
Manure has a long-standing role in worm farming. Red wigglers, often called manure worms, thrive in it. Manure serves as both bedding and a food source. Acceptable types include cattle, horse, rabbit, and chicken manure—so long as it’s aged at least 30–60 days. Fresh manure generates high heat during composting, which can kill worms.
You can often source manure for free from local farms. Use caution, though—some livestock receive de-worming medication that passes into the manure. Leach the manure (rinse it with water) to remove residues, urine, and salts if the medication status is unclear.
Key Bedding Tips
Regularly refresh your bedding by removing compacted, casting-rich material and replacing it with fresh bedding. Frequency depends on several factors:
Habitat size
Worm population
Bedding type
Food type
A small habitat with many worms may require bedding changes every 3 weeks, while a large, sparsely populated bin may last up to 2 months. Monitor your worms: if they’re climbing the bin walls despite having food, it could indicate bedding issues such as acidity or compaction.
How Much Bedding Should You Use?
Start with at least 6 inches of bedding. Add more if worms appear crowded. Composting worms, such as red wigglers, naturally live near the soil’s surface and tolerate high-density conditions well.
Bedding Summary
The most popular worm bedding materials are coconut coir, shredded paper or cardboard, sphagnum peat moss, and aged manure. Each has its pros and cons:
Coconut coir: Sustainable, great water retention, but may be pricier
Shredded paper: Inexpensive and dual-purpose, but harder to harvest castings
Peat moss: Affordable and effective, though not environmentally sustainable
Manure: Rich in nutrients and free in many areas, but must be properly composted
Changing bedding regularly is crucial for worm health. It prevents the buildup of harmful acids and ensures a steady supply of fresh, breathable material.
By choosing the right bedding—and knowing when and how to maintain it—you’ll create a thriving worm habitat that produces healthy, active worms and nutrient-rich castings.