Update, I built a second story on it. Made two gardens ontop of the first story, planted a tree in each of them.
I have a dirt staircase leading up to the top because the only way to get grass to grow on dirt is if it's near grass already. Unfortunately when there is only one grass touching one dirt, it takes forever for it to spread. I made grass on an island earlier and it took almost a whole day for it to even spread halfway across the land bridge. Almost two days to spread over most of the island.
Hopefully tomorrow it will have reached the top of my castle so I can remove the dirt staircase and just wait for it to spread up top. I also planted torches everywhere ontop of it because trees and grass only grow in the light, and torch light counts.
Also, we don't care if you aren't creative, you can still join us.
Can't sleep, clown will eat me.