Yes, you can do this with Dired+.
Mark all directories:
* / (command
diredp-insert-subdirs) to insert all of the marked directories.
You can also insert subdirectories in a recursive way (subsubdirs, subsubsubdirs, etc.).
To do that, you use
M-+ M-i (command
Like other directory-recursive commands (they are all on prefix key
M-+), this acts on files in the marked directories, gathered recursively, or, with a prefix arg, on ALL files in all directories, gathered recursively. In this case, the files it acts on are just directories, themselves.
So to insert all of the marked directories and their subdirectories (recursively), use
M-+ M-i. And to insert all directories and their subdirectories (recursively), use
C-u M-+ M-i.