Git add single subdirectory recursively

Question

I know I can add everything in my working directory with the following syntax:

git add .

I also know I can add the contents of a subdirectory with this syntax:

git add subdir/*

But how do I add everything (recursively) in a single subdirectory? I imagine it looks something like this:

git add subdir/.

Answer 1

git add subdir will add subdir and everything in it recursively.