You've probably seen one or another version of this potmaker. I wanted my husband to try making me one, and then I started looking at the soupcans I have been saving and realized it was the perfect shape for a potmaker! So I made some newspaper pots tonight and they were SO easy to make. I just cut long strips of newspaper about 4 or 5" wide, cutting through the length of the paper, through the centre fold. Then I wrapped the strip around my can leaving an overhang on the bottom. I wrapped 3 layers, and then folded the bottom in like I was wrapping a present, pulled out the can, and voila! instant pot for a seed to be planted. Best part is all of our newspapers are printed with non-toxic inks and they biodegrade quickly in soil, so the roots will be able to penetrate the pot and I can put these directly into my garden when the soil warms up. And if my seedling outgrows this size of pot before my garden is ready, I can just pop it, pot and all, into a larger sized newspaper pot (thinking I'll use the 454 mL size that tomatoes come in). As soon as seedlings get their first 'true leaves' they need to be moved into a larger pot -- my grannie always told me this is the key to getting a real head-start to healthy plants. She used to put a fan on her tomato seedlings for 10 minutes every day to guarantee strong plants. So tomorrow I'll be rummaging for crates to house all of these pots before I can plant them up. The key is to keep them all pushed close together in a crate, supported so they stay upright and don't squash down while the roots are making them firm and easier to move around. Also, I mustn't let them dry out.
AND, I read about using toilet rolls (I knew I was saving them for SOMEthing!) for planting earlier seedlings, like sweetpeas. They don't even need a bottom, just pop them into a container (I'm using a waxed paper ice-cream container that I've been trying to find a good second use for), fill with pre-moistened soil, pop in the seed to the required depth (I use an old wooden chopstick for making the hole) and water from the bottom up. When the seedling grows the roots will hold in the soil. And again, you can just pop the seedling inside the paper tube into the ground, eliminating root damage in the transplant. Sweetpeas and poppies and nasturtiums hate to have their roots disturbed, so this is a perfect solution. I usually plant all these directly outside, but if the ground is too wet the seeds will rot, and if its too cold they won't germinate so this gives me a head-start.
I'm wishing I'd asked people to save me their single-serving-yogurt containers as those would make perfect seedling planters too... aah well, there's always next year!
And here's an excellent re-use for plastic 4L milk containers. That will be my next project.