I just hate to think of potting soil ending up as landfill. Here's an idea for you to make your own compost, even if you live in an apartment. You will need a plastic trashcan/wastebasket (pick the size that is right for your situation: I would NOT use a big garbage can. A tall wastebasket is ideal). This will be your compost bin. You will also need EITHER an old sponge mop or Swiffer type thing (all you need is the pole and the head, you don't need the sponge, so get one out of the trash). OR you can buy a heavy duty paint stirrer attachment for an electic drill. These look like giant egg beaters with a long sturdy handle. Get one with the longest handle you can find. (You don't need a drill, just the attachment). This (the old mop or the stirrer) will be your compost turner.
Put the mop/stirrer into the compost bin. You will be adding your compost stuff on top of and around it.
Set the compost bin in an out of the way place. Begin by tossing in some shredded up newspapers (torn up by hand or run thru a shredder) and some of your old potting soil. You have the beginning of compost. Add to this, as you get it, coffee grounds (tear up the filter), tea bags (break open the bags), eggshells, more shredded paper, trimmings from your houseplants, spent flowers, etc. You COULD add vegetable peelings, apple cores, lettuce leaves trimmings, etc. as is, but what is better for your situation is to run these things through a blender or food processor first to grind them up into mush. Then pour the mush into the compost. Everytime you add a good bit of mush, add some dry stuff...paper towels, torn up newspaper, dry coffee grounds, dried out tea bags, more old potting soil... You don't want the mixture to get too wet.
Once you have several inches of this compost in the bin, gently lift and "toss" the stuff with your compost stirrer. Just a few up and downs on the handle is all you need, maybe every couple of days. Always leave your compost stirrer buried in the compost. That makes it much easier to lift and toss the compost.
Keep adding old soil, coffee grounds, paper, etc. a little at a time and stirring. If the mixture looks very dry, add a little water but you want it only to be slightly moist, not wet. Once the container is about 3/4 full, stop adding more, but keep stirring. You'll know when the compost is ready to use when you can no longer see bigger chunks of stuff (like apple cores for instance). It should smell like a freshly opened bag of potting soil.
The key is stirring; it's important to get as much air through this as possible thru stirring because you don't have air holes drilled in the container (a container with holes is too messy for an indoor compost operation).
NEVER add meat scraps, fats, fish scraps, dairy products, cat litter, dog waste, or primate droppings.
If you keep a pet bird/rodent, you can add the bird/rodent droppings/bedding. You can add the sludge from the bottom of the fish tank but you will need to offset wet high-nitrogen stuff with a lot of dry high-carbon stuff like paper (or leaves).
This can be scaled to whatever size of "composting operation" you can manage. When I lived in an apartment I had one of these mini composters in a wastecan in the kitchen and it worked very well. You might also want to look into worm composting; google on "Vermicomposting" for more information.
I have lots of pots but cannot just keep filling them. Now I am taking pots and dirt to the
I want plenty of organic matter but also want well-draining soil. If I had to guess I would probably be using 1/3 old potting mix to 2/3 everything else (by volume).
