Here’s a green idea I found on Pinterest using toilet paper rolls. You can get two planters out of one tube. Cut the tube in half and cut 4 slits evenly spaced on one side of the roll about 3/4″ up or so. Fold the ends in as you would close the top of a box.
Fill the mini planter with a lightweight seed starting mix. Plant your seeds and water thoroughly. Place the planter in a sunny windowsill and keep moist. Once your seedlings have about 4 leaves they are ready to be transplanted into a larger pot or directly into the garden. Open the bottom of the tube and plant the whole thing or gently remove the plant and set into the soil.