An excellent blue Sage, Salvia x sylvestris 'Blue Hill' or 'Blauhugel' forms eye-catching, compact, bushy clumps that are covered with stunning spikes of rich violet-blue flowers, appearing in early summer and lasting throughout the summer. Reliable, this erect, bushy herbaceous perennial grows in round clumps of mid-green, aromatic foliage, up to 18-24 in. high and wide (45-60 cm).