Name: Evan Pioneer Valley south, MA, USA (Zone 6a)
You don't see a right sidebar Josephine?
If you use the left sidebar it will search all forums. However there is a pull-down you can use to select the forum you want. Right sidebar search box searches the forum you're in.
threegardeners it's possible but I have other priorities ahead of that right now.
frostweed: the right bar appears on the front page of the forum you're looking at. It's a blue bar on the right. So you'll have three columns actually.