"The vegetables grow."
Translation:La verdura cresce.
It's not too strange sounding, as you can use the plural to emphasize diversity, especially if you're mixing leaves (erbaggi, like lettuce or endive), roots, fruits and flowers (ortaggi, like carrot, cauliflower or eggplant). But you don't have to, as the singular can cover for those too, so "La verdura cresce" means the same. When referring to a single vegetable, you'd normally call it by name or by its class (ortaggio is common, erbaggio is kind of rare), unless you refer to its belonging to the vegetable kingdom, in which case the correct Italian translation would be "il vegetale".