Make block change after time

I've made a leaf block and a leaf block with fruit and I have found a way to make it grow fruit after time (image attached).

Now what I need to know is will this work when the block generates in a structure and how to have it grow again after being harvested (You can harvest the fruit by right clicking, turning it back).

And before you say that I haven't searched before asking, Yes I have I just haven't found a good answer yet.