The special Prize Shovel gets you twice the Prize Good points when using it to harvest Crops and Heirloom Trees. After purchase, it is yours to use for 24 hours. You can view the cooldown timer on the County Fair Board.
To use the Shovel, simply harvest your fertilized Crops and Heirloom Trees!
After the cooldown timer runs out, you can purchase more from the County Fair Board or from your Medal status in the Neighbor Bar.