Most Commonly Asked Compost Questions

QUESTION: Must I use a compost bin?

ANSWER: No. You can build a pile if you wish. Bins are just devices to control the composing material, allow air to enter it, and keep rodents away.

Q: Should I add fertilizer to the compost pile?

A: You can add a little high-nitrogen fertilizer to help speed up the composing process if you don’t have enough nitrogen-rich green material like leaves and grass, but that usually isn’t necessary.

Q: What do I do when the compost pile shrinks? Do I add more material.

A: No. It’s normal for the pile to reduce in size as the material breaks down. It will lose from 1/4 to 1/3 of its bulk within a month or two. Don’t add fresh material to the working pile. Instead, store it until you have enough to start another.

Q: Should I do something if insects are in the pile?

A: It depends on what type of insects. Some, like small beetles, sow or pill bugs, centipedes ane certain types of ants, actually help the composting process. They’re more likely to be found in a compost device less than one cubic yard (3’x3’x3’) since the pile won’t reach a high enough temperature to eradicate them. If your composting method is harboring houseflies, you can correct the problem by turning the material and allowing the pile to heat up. Also, when you add kitchen scraps to the pile, be sure to turn them under so you don’t attract flies or fruit flies.

Q: Can I use the finished compost to feed all my plants?

A: No. Compost is really a soil additive. It does have some nutrients, but not enough to be he only fertilizer for your plants. You can either spade the humus into the soil or put it on top as a mulch. Either way, you’re improving the soil quality and texture.

Q: Why is there a bad smell from my compost pile?

A: The pile has become anaerobic because the correct amount of oxygen isn’t reaching the entire pile. You can correct this by adding carbon-rich material or old compost and turning and mixing the pile.

Q: Can I recycle my pet’s wastes in the compost pile?

A: Only if you have rabbits, goats, horses, sheep or cattle. Never add dog or cat droppings or litter.

Q: Do I have to turn the pile?

A: No, but it speeds up the composting process and helps the pile achieve high enough temperatures to kill insect eggs and weed seeds. But you can leave the pile alone and you’ll get finished humus in a year or two.

Sources: Sherl Hopkins, Common Ground Garden Program, UC Cooperative Extension, and Joseph Keyser, director of programs, American Horticultural Society .