Afaik there is no way to recursively copy directories via sftp with the normal command line client.
So you might either do as suggested in that other thread, using for example gzip with the -r switch for recursive operation and gunzip to uncompress it. There are other compression tools like bzip2/bunzip2.
Not all of them have an option for operating recursively on directories so a common way is to tar them 1st, and then compress.

It implies of course that you have a possibility on the recipient side where you upload your data, to uncompress and/or un'tar there.

The most simple way might be a graphical interface like for example Servant Salamander which can use many different protocols including sftp (if this is an option for you). The advantage is that you dont have to worry about de-/compressing and stuff, since it just scans your local directory structure you want to submit and just creates it accordingly on the recipient side.