and thought to give it a try... Guess what??? It actually works!!!
On the left is lettuce and on the right celery. So, now what? Do I need to put them in earth? The celery has roots, the lettuce doesn't, at least not yet.

Of course I left eye-holes and luckily the glue seems to dry pretty fast so the bears weren't trapped for too long (although I turned on an extra little heater and closed the door after finishing).
However, in our garage I discovered some forgotten bulbs that have decided it is Spring, darn it all... obviously they haven't looked out the window. So I have my first glimpse of Spring in a world of white... I'm going to put these mystery bulbs in some dirt tomorrow and bring them inside where they can tell me more about the season to come.