Here's what my HC looked like in March, a month or so after initial planting.

Then May, approx. 4 months after planting that chunk from PetCo. You can tell it has already spread quite a bit!

I loved that little shrimpie.
And here is that same tank earlier today, 4 months after that last picture, 8 months after initial planting. I really should have gotten a picture BEFORE I started ripping it up, but you still get an idea...