1. Eggshells If you’re looking to add a little whimsy to your windowsill, you’ve found it: Eggshells are perfect for to grow tiny green plants like chives, alfalfa sprouts, or wheatgrass. Just slice off the top of an uncooked eggshell with a knife, empty out the egg and yolk (and save to cook later), and give the inside of the shell a quick rinse. Once it’s totally dry, fill it two-thirds of the way with potting soil. Up for some fun? Give your egg planters some personality by gluing on some googly eyes, like this guy did.)
  2. Coffee or soup cans They’re bigger than eggshells, which means they can accommodate larger plants like basil, parsley, or microgreens. But before you fill ’em up, use a hammer and nail to poke a few holes in the bottom of the can. The holes will allow for drainage when you water your plant, so the roots don’t end up soggy. (To catch the drained water, place a curved plate or pie plate underneath.) Also, while you’re at it, save those used coffee grounds: Sprinkled on soil, they make great plant food. MORE: What’s Better: Organic or Heirloom?
  3. Tea tins Not a coffee drinker? That’s OK. Empty tea tins work just as well, and will make your apartment windowsill look like something out of a Meg Ryan movie, if you’re into that sort of thing. Like coffee cans, poke a few holes for drainage and place the tin on top of a curved plate or pie plate.
  4. Cardboard berry containers Those green-blue mini crates you use to tote strawberries home from the farmer’s market make a rustic addition to your windowsill when there are herbs sprouting out of them. Just fill it two-thirds of the way with soil and plant seeds for small-to-medium herbs like oregano, thyme, or mint. And since they’re cardboard, you’ll always be careful not to overwater, lest your container garden ends up disintegrating. (Bonus: They already have holes for built-in drainage. Nice.)
  5. Milk jugs Lop off the top of a plastic or cardboard milk container and poke a few drainage holes in the bottom. The slightly bigger size works well for slightly bigger plants, like basil or parsley. Don’t do dairy? No problem—your plants are cool with almond, cashew, hemp, whatever.
  6. Old sneakers The fact that a bunch of green stuff will make itself at home in those stinky, worn-out running shoes might be proof that plants will bloom literally wherever they’re planted. Use an electric screwdriver to create fast drainage holes, then plant small to medium herbs like oregano, rosemary, or thyme. MORE: Is Indoor Vertical Farming the Future of Food?
  7. Eco-friendly paint cans Because what’s better than turning the remnants of your old DIY project into a fresh new one? You probably don’t want to grow something in a can that used to hold crazy toxic conventional paint. But cans that were filled with eco-friendly paint—nontoxic, water-based paint that’s free of things like VOCs,  ammonia, and formaldehyde—are a great way to house slightly larger plants, like tomatoes. You can leave your can as-is for a rustic look, or gussy it up with decorative oilcloth like this. Always wash your can thoroughly before planting, and check with your municipality to find out how to dispose of old paint safely.
  8. Wine corks For real: If you hollow out the center of the cork with a screwdriver head or paring knife, you can actually grow something in there. Obviously, it’s got to be super small, like a few blades of wheat grass. But if you’ve got a bunch lying around (someone’s been having fun!), plant them all and line them up like soldiers along your windowsill. MORE: Yep, There’s Now a Ketchup ’n’ Fries Plant
  9. Muffin tins Find a well-worn pan at a yard sale or flea market, and hammer-and-nail holes in the bottom of each cup for drainage. Depending on the size of your plant—from microgreens or sprouts to parsley or basil—try a mini, regular, or jumbo muffin tin.  
Nine Ridiculously Easy Ways to Grow Veggies and Herbs Inside Prevention - 11