Almost all garbage bags are made of polyethylene, which is thought to be the safest plastic. However, unless it is specifically "food grade" plastic, the dyes and other chemicals used in the processing of the plastic will leach into the soil. Is it enough to really matter? I doubt it. But if you want to be on the safe side, use "food grade" garbage bags, which you can get from restaurant/kitchen supplies. They aren't expensive, but they're usually clear and somewhat flimsy. Ziploc bags meant for food storage are also obviously food grade, and made from polyethylene. Compostable garbage bags should also be safe, but would they last a growing season? I don't know.

You can use pretty well anything that holds the decomposing matter but, with any container the size of a garbage can you want to be able to get into it to remove the finished product. This winter, put an amount of snow into the container. Then try to get it out. Its wet, and its heavy. Try to put a spade or shovel in there and bring out what you can. Very difficult to manoeuvre a shovel from the top to reach into the container to remove anything. Containers with wet (damp)composting matter has weight which you might think you can roll around, but once you dampen it, it becomes a sotted mass which is very heavy. You'll be lucky if you can put it down on its side, let alone roll it. And then whaddya do....lift it? Good luck! For $200.00 you could build a better mousetrap or the luxury penthouse of a compost bin. For that much you could buy double the amount of wood and build a proper compost bin. For a lot less than that, you could build a couple compost bins with old wood pieces. There are a number of recipes for building a compost bin on the network. Location, location, location ...is important so read articles on 'where to put a compost bin'.

While there are 'uses' for the used soil, I wouldn't reuse it AS a soil, in part because of the increased likelihood of it harboring disease organisms, but primarily because of it's advanced state of decay, more specifically because of the fact that it will be broken down into particles much finer than the the size of particles when it was originally pressed into service. This fine particle size reduces aeration and increases water retention in what odds say was already problematic or borderline so in those areas. If you can find pine bark in an appropriate size, you can make a soil, using your old soil as a smaller fraction of what you're making ..... and gain a substantial savings for your effort. More on that if you're interested. You can over-winter your eastern white cedars ('cedars' being a misnomer) in their pots, but in order to maintain top vitality it will almost certainly be necessary to repot in the spring - preferably into a medium that allows you to water appropriately. More on that too, if you have interest. BTW, how you should or can successfully over-winter them depends on where you live. Al

Look for bags that say they are "compostable" (even if you don't compost). You can buy them on Amazon; they are ecofriendly and biodegradable even in a landfill without air and light. The downside is that they will also break down in your main garbage can as you wait for however many days for garbage pickup in your town. I have been using the non-eco-friendly Hefty The Gripper bags since forever, mostly because I like the drawstring, and because my mother used Hefty bags when I was growing up, so those are the ones I automatically reach for at the supermarket without thought. They do the job. But I do feel I need to switch to something that at least is from recycled materials. I will be following this thread for suggestions. As to bags that will break down, I am thinking about trying Green Earth bags, but don't yet have firsthand experience with them.