Can't place objects

Hey everyone,

I just got the museum quest and I have to decorate around the museum. I haven't started decorating my house and plot so I don't know if I'm doing something wrong but I crafted a bunch of hedges, a bench and potted flowers but when I went to the museum to place them I couldn't. I clicked on the item in my inventory and I didn't have the option to place them, just to drop them. So I did that but they are floating in boxes and go right back in my inventory. Also they are just yellow in my inventory, they don't look like the things I crafted, if that makes sense.

Did I do something wrong?

Thanks!