I am not aware of any ls option, that will list only directories.
You may consider following:
ls -F | grep /
-F inicates all directories with a slash as suffix
find . -type d -maxdepth 1
will list all directories
if this is too much typing, then you can define an alias. e.g.
alias lsdir=´ls -f|grep /´
so lsdir will list all subdirectories within the working directory.