How to make a food item plant seeds?

I'm back again!

I'm making a plant that is similar to that of the sweet berry bush. I want the sweet berry to have the same affect where it is both edible and the seed for the bush. As of right now there is no variable that I know of on a food for when it is right-clicked on a block, right now I have it as when it is right-clicked which spawns the plant right where the player is standing but also is edible at the same time. 

Maybe the developers could add a right-clicked on block event to the food item.

Thanks