I have various extra vegetable seedlings and was thinking about planting them way in the backyard for the animals to enjoy. I do not intend, however, to monitor them for pests or disease. Can this be a bad idea?
It depends on where your "keeper" vegetables are. Will youo be luring critters into the area? The animals might not be able to distinguish between what is theirs to eat, and what is yours.
If I had extras, I'd go ahead and plant them, maintain them, and give the produce to neighbors, a soup kitchen, or the local food pantry. That way you get the fun of growing and someone gets needed food.