Untested:

use Path::Tiny;
path('fred')->visit(
  sub { -f || -d and $tar->add_files($_) },
  {recurse => 1}
  );
[download]

EDIT: Fuller version (still untested):

use Archive::Tar;
my $tar = Archive::Tar::->new();
my @filenamelist;
use Path::Tiny;
path('fred')->visit(
  sub { -f || -d and push @filenamelist, "$_" },
  {recurse => 1}
  );
$tar->add_files(@filenamelist);
$tar->write("fred.tar.gz", COMPRESS_GZIP);
[download]

SECOND EDIT: Because I like Path::Tiny better than File::Find, although it has its quirks. For example, in the callback, $_ is a Path::Tiny object instead of a plain string, hence the "$_" which "stringifies" it.