Tree Food is a special fertilizer used to grow the Tree of Wisdom. It costs $2,500 per bag and can be purchased at Crazy Dave's Twiddydinkies. It can be fed to the Tree of Wisdom one bag at a time each one making it one foot taller. In order to grow it to 100 feet, the player will need to spend $237,500. So, in order to grow it 1,000 feet, the player will need to spend $2,487,500.