Sowing in milk jugs definitely works. I had great success last year with a couple of differences from the article.
1. A starter mix tends to work better than potting soil -- less damage to roots when transplanted.
2. Don't keep the lids on the jugs -- moisture builds up and can cause mold/rot the plants.
3. Don't worry about punching holes in the bottom - the slits and open top are plenty of ventilation and you don't want roots to grow outside the container or your new plants may be damaged when transplanting.
4. I use packing tape rather than duct tape -- easier to open when ready to transplant.
5. Be sure to label the jugs -- a black felt marker worked fine for me.
6. Place jugs in the snow in any area of the yard that gets the most sunshine. I put these along a fence or building (protected area) rather than out in the middle of the yard.
7. Sow seeds as suggested on packages (ie. some take 6 weeks to germinate and some take longer) so bear in mind when you want to plant these out.
8. Don't worry too much about checking for moisture. The jugs are unlikely to need additional water for 6 weeks or so unless the weather gets unusually warm.
9. Use a utility knife to cut the jugs -- easier than a kitchen knife.
