“Pinocchio, basta! I see you!” Isabella Rossellini was scolding her spotted mutt, hoping to keep him from mauling a hen that had strayed from her coop. Can’t take your eyes off them, can you? Ms. Rossellini was shaking her head, her watchfulness maternal.

These days, when she is not acting, writing, making films or modeling — she recently signed a new contract with Lancôme, the cosmetics company — she is minding her Long Island farm. On a 28-acre tract in Bellport, N.Y., with the help of some friends, she breeds chickens, grows organic vegetables and produces honey and eggs.

She doesn’t mind getting her hands dirty. After leading visitors to a hillock that turns out to be a compost heap, she plunged a fist deep inside, urging us to do the same, so that we could feel the heat generated by its rotting leaves.

It doesn’t bother her either to scatter dried worms to the turkeys and 100-odd heritage chickens that trail her wherever she goes. “When they are small, I sit with them in their boxes,” Ms. Rossellini said of her oddly speckled and spotted brood. “That way they get used to me.”