Since the ducks are wild about lettuce, and I could do better eating more of it myself, I am starting several pots full of it, myself. The slug problem is much less now that the ducks have been here a couple of years, but there are still some slugs out there.
Anyway, I have found that railing planters produce a pretty good amount of lettuce, and the slugs cannot get at it. I have railing planters on top of the Day Pen, where I will be able to harvest and feed the ducks right there. And I won't forget to water, because I am often near the Day Pen, which has a source of water (and fertilizer
).