Plant Food boost

The Plant Food Boost is an item that can be activated before a level is started when selecting the plants that lasts for the duration of that level. Any plant from that Seed Packet will do its Plant Food effect upon being planted. There are only two ways to activate it. One is to have a boost already obtained from the Zen Garden, which is obtained by fully growing a plant besides the Marigold in the Zen Garden, and choose the Seed Packet of that plant for a level. Another is to pay a varying price of gems (up to 15) to activate the boost for that level.