Green Thumb Cards is a virtual version of an actual card game. Four players (up to 3 of which can be played by the computer) take cards featuring flowers, garden pests, helpful tools and random acts of nature. Players try to obtain complete sets of flowers by taking cards from the stack, stealing cards from another player, or picking up cards out of the center walkways. For example, it takes 4 roses to complete the rose set. Once a player has successfully planted all cards of a set in their garden, they have earned the points for that set and can no longer lose those cards. Other players can steal cards by using a pest card. Pests can be defended against by using the appropriate defense card. The player who has earned the most points when all cards have been used is the winner. Game featured net play as well as offline play.