In the comments section to my Christmas Eve post, Medo asked how I made my containers for wintersowing. Here's a 36 second clip of how I do it. Be sure to turn your volume down. It's not a quiet activity.
If you have access to a bandsaw or a friend with a woodworking shop, you can make almost 200 containers from 2-liter bottles in just a couple of hours. Be sure to rinse the bottles out first or else you'll find that sawdust and dried cola don't mix well.
Ready to be filled:
Done and waiting: