Keeping Rats out of the Compost

(Question)

I want to restart my compost this spring after two years of not using it. I stopped after 2014 when I was attacked by flying ants when I went to the compost in the evening. I don’t think the ants were in the compost but in the ground near it.

No flying ants were around last summer, but a block and a half from me, one property (that I know about) has rats and a friend of mine in another part of Toronto (Scarborough) told me about getting rats in her compost. She no longer composts. So, how do I keep rats from being attracted to my compost bin and keep them out? My compost bin is from the City of Toronto and is four and a half years old. It is closed on all sides and the top, but of course the bottom is open to the ground so rats could get in there.

 

(Answer)

Thank you for contacting Toronto Master Gardeners. Home composting is a great way to make your own free organic soil amendment. Rats are a fact of life in the city, but there are a few strategies to help avoid attracting them to your compost.

The first is to make sure you are putting the right ingredients into your compost. Fruit and vegetable scraps, and yard waste such as fallen leaves and grass clippings, are ideal. Fruit and vegetable scraps can be covered with a layer of soil or sawdust to mask some of the odour. Never put cooked food, meat, fish, poultry, animal bones, dairy products, or fatty foods into the compost.

Second, make sure to turn your compost regularly and keep it moist. Not only will this speed up composting process, but it will also deter rats (and mice) from making a nest in the compost.

A compost bin that has closed sides and a proper fitting lid, like the one you have from the City of Toronto, will help keep rats out. The bottom is still a potential point of entry, as you have mentioned. I would recommend starting out with the bin that you have, keeping the above tips in mind. If rats do become a problem, consider investing in a compost tumbler for your fruit and vegetable scraps. You can still use your existing bin for yard waste.

Clemson University Cooperative Extension has a useful page with information on composting that can be found here.