How do you use it, and can you use more than one ginger flower at once?

When you have 0 days left for your Secretary Bird, and you visit it's page it should have a "Use" button next to an image of the Red Ginger Flower in the Mushroom Hole/Name Secretary Bird area.
I'm fairly certain that you can only use one at a time being that you can only use them when you have 0 days left.

Thanks so much!