Q: This has been plaguing me and after reading the recent post about organizing kitchen garbage I started fretting all over again. With high hopes for greenerizing our lives, we started a compost bin in our yard last year, the kind with stacking sides and a lid. I added to it regularly and, for the first 6 months, dutifully and backbreakingly turned it over every week. Over the winter rains when our CSA was suspended, we let it ride. This spring we had a pretty reasonable compost that I spread around. I started adding again, but we had a new baby and I was out of the habit of flipping so the veggies kind of piled up.
And then we saw a rat...
...Ugh. My husband immediately transferred the compost in progress to the city bin and we have been putting our scraps out for pickup ever since (and we haven't seen any more rats). But it annoys me, because the company that picks it up sells their compost to farmers rather than making it freely available to residents as the old company used to do. Plus I kind of want my precious organic scraps to enrich my pitiful garden rather than slumming it with all the conventional carrot peels working for a living out there.
But the possibility of rats makes my compost heap a non-starter...or does it? Is there something I could do differently to prevent attracting them or do they come with the territory?
Asked by Ann
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You could modify some of your composting habits to make the heap less appealing to rats.
First off you need more green and brown. In other words, green grass clippings, yard trimmings, and leaves. If you use unbleached paper products, spent coffee filters and paper towels are also good.
Try for a ratio of about 60/40 green and brown to veggie scraps. Things like potato peelings, citrus rinds, used coffee or tea (including the teabag), lettuce, carrot tops, and eggshells aren't that attractive to rats or mice, although if they are starving they'll eat anything. Make sure your compost is adequately moist, even watering if things are dry.
If you have predominantly fruit scraps then consider discarding most or all of these. Don't compost cheese, leftovers, meat, pet food, eggs, milk, sweet potatoes, nuts, peanut butter, basically anything sweet or fatty.
Also remove anything small and shiny near your compost. This includes shiny nuts and bolts, bits of tinfoil, small plastic colorful toys. If you saw a wood rat, they are notorious for stealing bright things to adorn their nests. It's where the term "packrat" comes from. Nesting material is also suspect like cotton balls, bits of fabric, fiberfill from pillows, and down feathers.
You can also plant in your fallow garden a cover crop such as hairy vetch, clover, alfalfa, etc. When it's time for planting, cut the cover crop and put in your compost heap. Dig the roots of the cover crop into the soil.
If you feel bad about discarding some of your scraps then buy an enclosed compost tumbler and "pre-compost" the attractive stuff, then once it's halfway decomposed, move it to the main compost heap.
There are a number of things you can do. Since NYC has a rat "issue" and we have a number of community gardens, there are some documents re best practices re rats:
https://gis.nyc.gov/doh/rip/docs/Rodent_Control.pdf
The main things seem to be:
- reinforce your bin with wire mesh and makes sure it closes
- getting it on a solid base so they can burrow up through the ground and in is helpful
- not having it placed up against a border/yard edge/other items is helpful (rats are less likely to run through an open field to get to a compost bin than along a wall or fence, through clutter, etc.)
I have actually seen cats keep rats away from the garden because they chase the juveniles and the scent of a cat around in general is usually a good deterrent for rats - unless the food is such easy pickins' that they will risk cat attacks anyway. (It's true that cats alone can't control rat populations though - you have to be good with waste control, too!)
Also, I have heard mint being planted around the compost helps but some gardening communities say otherwise.
In seeking out that info, I did find this link, which says you can bokashi your compost which apparently repels rats?
http://organicgardening.about.com/od/pestcontrol/a/ratsincompost.htm
Some jurisdictions are meant to be 100% rat-free (as they are an invasive species) and have a number you call to report rats when you see them.
You can always get a compost tumbler which are kind of pricey. If you and you husband DIY here is another option.
http://www.instructables.com/id/compost-bin/
the city of seattle offers the green cone at a discount to its residents. its not suitable for yard waste, but ours is awesome and critter-free. everything planted near it is thriving.
http://www.greatgreensystems.com/
We went through about four different kinds of compost bins before we landed on a solution that was rat-proof. We had rats not only burrowing into and feeding from the active bins, despite all scraps being buried well, but also discovered a mama rat with a whole litter living in one of the bins that was left alone to decompose.
We ended up making our own bins out of large plastic trash cans, similar to this one:
http://video.about.com/greenliving/Homemade-Compost-Bin.htm
We drilled small holes all over the bin, and for good measure added some 1" holes under the lip of the rim, gluing some leftover metal screening over the holes from the inside with heavy-duty plastic adhesive (I sanded the bin first for better adhesion). In retrospect, I don't really this this was a necessary step.
Initially the rats investigated but gave up trying to get in. Putting the cans up on cement blocks keeps rats from being able to chew at the base. So far it's actually my favorite compost bin system, since the black plastic enclosure helps really speed decomposition, and ended up being the cheapest option by far that we tried.
Thank you all SO much (I'm Ann). These are really constructive ideas.
Though we got our stacking bin at a discount through our town, we had resigned ourselves to springing for a tumbler, but now I think we'll try that nail-hole garbage can idea. There was definitely a tunnel up the middle, so a bottom-side barrier seems essential.
I am wondering about the more discouraging bins - I can see how they would protect the compost, but I want the rat(s) to leave the premises altogether. Do they ever GO AWAY or is any active garbage pile an irresistible lure?
I guess I'll have to make a point of adding dry stuff and see.
We have already got a worm bin, so maybe we'll try that as an interim measure if it's not too high-maintenance.
There are a number of neighborhood cats who regularly patrol, so I also will yell at them to quit loafing.
We've been successfully using a food digester for several years since we had the same problem.
http://www.vegetablegardener.com/item/8890/diy-food-scrap-digestercomposter