When a big new yellow tractor arrives, Otis the friendly little tractor is cast away behind the barn, but when trouble occurs Otis is the only one who can help.

The story of various farm animals and how their activities revolve around a big red barn.

The pigs, Pete and Paul, are eager to help Farmer Bill grow the best and biggest watermelons so he'll win at the annual Fruit and Vegetable Show, but their overzealous efforts to help the melons grow faster end up destroying the entire melon patch. Tractor Mac and friends teach Pete and Paul that with patience and care, they too can grow a prize melon.

Tractor Mac is at the farm doing a variety of chores.

When a tornado threatens the farm, Otis the tractor must try to save the animals, including the unfriendly bull.

When Otis the tractor becomes trapped in a burning barn, after rescuing kittens, his animal friends and local firefighters come to his aid.

Though confined to a wheelchair, Jonathan faces the terror of a tornado all by himself and saves the lives of the horses on the family farm.

While spending Christmas at their grandparents' farm, Lily becomes convinced that her younger brother Liam is right about White Cow being lonely and helps him seek a companion for her, leaving little time for Christmas preparations or reading.

Tractor Mac and his animal and vehicle friends wrap gifts, bake holiday treats, decorate a tree, and get ready for Christmas.

Describes the activities on a busy family farm from the spring when preparations for planting begin to the autumn when the cats grow winter coats and the cold rains begin to fall.