What to Feed Worms (and What to Skip)

Red wigglers are famously low-maintenance — until you start feeding them the wrong stuff. A happy bin can process roughly half its worm weight in food every single day, but pile in the wrong scraps and you'll end up with a smelly, anaerobic mess that drives your worms to the lid (or worse, out of the bin entirely). Here's everything you need to know about what to feed worms so your colony thrives.

The Best Scraps for Red Wigglers

Think of your worm bin as a slow cooker that runs on microbes. Worms don't actually bite through food — they wait for bacteria and fungi to break it down first, then eat the microbial layer. That means soft, moist, nitrogen-rich scraps are gold.

• Fruit scraps — banana peels, melon rinds, apple cores, berry tops. Worms go absolutely wild for overripe fruit.
• Vegetable trimmings — lettuce, carrot peels, zucchini ends, cooked or raw (plain, no oil or salt).
• Coffee grounds and paper filters — one of the best worm foods out there. Grounds add grit that helps digestion and slightly lower pH, which most bins handle fine in moderation.
• Tea bags — just remove any staples and check the bag isn't plastic mesh.
• Crushed eggshells — not exactly food, but they buffer pH and provide calcium. Crush them small so they don't slow breakdown.
• Cardboard and plain paper — torn into strips and dampened. This is your carbon source and it's just as important as the food scraps.

How Much and How Often to Feed

Start conservatively. A pound of worms (roughly 1,000 red wigglers) can handle about half a pound of food per day under ideal conditions — but a new bin with a young colony should be fed much less while the microbial community gets established.

A good beginner rhythm is to feed every 2–3 days. Before adding a new batch, check that the previous feeding has noticeably broken down. If you can still clearly identify last week's banana peel, hold off. Overfeeding is the number-one mistake new worm farmers make, and it snowballs fast.

Prep Makes a Big Difference

Chop or blend scraps into smaller pieces before feeding. The more surface area exposed, the faster microbes can work. Whole broccoli stalks or uncut melon rinds can sit for weeks; dice them up and they'll be gone in days. Some worm farmers keep a dedicated blender just for bin prep — it sounds obsessive until you see how fast your bin processes the slurry.

Keeping the Carbon Balance Right

Every time you add nitrogen-rich food scraps (greens), you need to balance with carbon-rich bedding (browns). A rough rule is a 2:1 browns-to-greens ratio by volume. Good browns include shredded cardboard, brown paper bags, newspaper, dry leaves, and coco coir. Without enough carbon, the bin turns wet and acidic, ammonia builds up, and worms start escaping.

Always bury food scraps under a layer of bedding. This keeps fruit flies down, reduces odor, and keeps moisture more even throughout the bin.

Foods to Avoid Completely

Some items don't just slow the bin down — they actively harm your worms or create conditions that attract pests.

• Meat, fish, and bones — they rot anaerobically, create foul odors, and attract rodents and flies.
• Dairy products — same problem as meat. Cheese and milk curdle and create ammonia spikes.
• Oily or heavily seasoned food — oil coats the worms' skin and interferes with their ability to breathe through it. Salt dehydrates them.
• Onions, garlic, and leeks — the sulfur compounds irritate worms and slow consumption significantly.
• Citrus in large amounts — a little orange peel is fine, but too much acidifies the bin. Add eggshells to counteract if you go heavy on citrus.
• Glossy or colored paper — inks and coatings can contain toxins. Stick to plain newspaper or cardboard.

How to Recover from Overfeeding

You'll know you've overfed when the bin smells sour or like ammonia, the bedding is soggy, and worms are piling near the top or escaping. Don't panic — it's recoverable.

1. Stop feeding immediately — give the bin at least a week, sometimes two.
2. Add dry bedding — handfuls of shredded cardboard will absorb excess moisture and re-balance the carbon ratio.
3. Gently turn the bedding — this reintroduces oxygen and breaks up compacted anaerobic pockets.
4. Check for and remove any rotting pockets — pull out anything that looks black and slimy rather than brown and crumbly.

Getting the feeding routine right is honestly the whole game. Stick to fruit and vegetable scraps, match every food addition with bedding, chop things small, and resist the urge to dump a week of kitchen waste in at once. Your worms will reward you with rich castings and — perhaps more importantly — zero drama. If you're just setting up your colony, our red wiggler care guide covers bedding setup, moisture levels, and temperature ranges to pair with what you've learned here.