Squirrel defense

Squirrels apparently like to dig in nice soft dirt. This is a problem for my newly planted beds.

This rose clearly needs a massive pruning

I bet the thorny branches would make a mean mulch. 

And I also hear the don't much like this stuff:

So I will try sprinkling that over the soil surface. 

What else can I do to discourage squirrels from digging up and ruining my freshly-planted beds?