Mindy's father is obsessed with gardening. He and their neighbor Mr. McCall are in a constant battle over whose garden looks the best. With the annual garden show soon approaching, both men are determined to win first place.
One day, her father drags her and her brother Joe on a trip to Lawn Lovely to purchase some new lawn ornaments for the front yard. He is immediately drawn to a pair of lawn gnomes he names Hap and Chip. Mindy is repulsed at the sight of them — they look evil and mischievous. She begs her father not to buy them, but he does so anyway. As Mindy's summer continues, strange things begin to happen. Mr. McCall's garden is vandalized — his precious melons are smashed to pieces. All signs seem to point to Joe, but he denies having anything to do with it.
Joe comes to the realization that the gnomes must be alive and causing all the mischief. He tries to convince his parents and Mindy, but they don't believe him. Eventually, Joe's suspicions about the gnomes are confirmed when Mindy sees them for herself.
The gnomes trick Mindy and her brother into going into the basement of Lawn Lovely, where they say several other gnomes are being held against their will. The gnomes quickly turn on them, but Joe is able to freeze them in their tracks with the sound of a dog whistle.
She is something of a perfectionist. She annoys Joe with her constant need to keep things neat and in order, such as her clothes, which are lined up by colors of the rainbow. Mindy and her brother are constantly teasing each other, and most of the time, she is at the receiving end of one of his and his best friend Moose's practical jokes.
Joe describes Mindy as tall, blonde and skinny, much like his parents.