Branches in the remote
I still obtain a lot of branches in the remote, even though the don't appear in the web interface, if you list all branches in a terminal:
bash-4.3$ git branch -a
AddPlot
AddSparseArithmetics
* master
remotes/origin/AddPlot
remotes/origin/AddSparseArithmetics
remotes/origin/HEAD -> origin/master
remotes/origin/master
remotes/origin/patch-1
remotes/origin/patch-2
remotes/origin/patch-3
So the branches are not actually removed