Making A Plant

so i've been making a food mod that has blueberries in it. i'm trying to make a sweet berry bush that drops my new blueberry and so far its kinda working. but the problem is, whenever i place ANY block, it turns into a full grown blueberry bush. i have no idea why and i need help answering this. also, i coudnt figure out how to make a bush appear when i right clicker the ground with the berry (it went next to me no matter where i placed it) so i made seeds for it. when i place the seeds, it removes the block below it replaces it with the plant growth stage 1. pls help me i'm so confused