A
B
C
B-rated items
Below is a complete list of items that have earned a Vermicompost Score of B. Use them to supplement the A-rated staples, but be mindful of the quantity. Click on any item to learn the specific reason for its B-rating and the best way to prepare it.
White office paper
Pine needles & conifer
Sawdust
Broccoli
Garlic
Tea bags
Watermelon
Red Currants
White Cabbage
Cauliflower
Large, hard pits
Shallots
Bread, pasta, rice, and grains
Pointed Cabbage
Pineapple
Red Cabbage
White Asparagus
Wood ash
Envelopes
Radishes
Twigs
Cherry Tomato
Fresh grass
Mango
Pomegranate
Sand
Natural textiles
Leek
Kale
Tumble dryer lint
Tomato
Spring Onions
Avocado
A
B
C
Score A (Ideal)
A
B
C
Score C (Avoid)
These materials should never be added to your vermicomposter. They pose risks like harming worms, attracting pests, causing bad odors, or simply won’t break down. These belong in a different waste stream. Some C-rated items to add with great caution are coconut, lime, peppers, onions, glossy paper, or dairy products.
Frequently asked questions
Why are these items rated B and not A?
B-rated items have properties that can disrupt a bin if added in large amounts. This could be high acidity (like tomatoes), high fat content (like avocado), or a tendency to get moldy (like bread). They are not harmful, just require more balance.
What happens if I add too much of a B-rated item?
Typically, the system will slow down, or the bin might become too acidic or wet. In some cases, it could attract pests. The solution is simple: stop adding the item for a while and add more ‘browns’ (like cardboard) to restore balance.
How can I safely add B-rated items?
The key is variety and small quantities. Don’t add a large amount of one B-rated item at once. Mix small amounts with plenty of A-rated items and always ensure they are well-buried under the bedding.

