Perovskia - russian sage - don't get confused its not the yummy cooking sage, however you can nibble the flowers if you fancy. Although it does make a lovely upright perennial that has heavenly fragrant grey green foliage and masses of violet blue flowers from late summer to autumn. They look really lovely when planted on mass and mix well with grasses and echinaceas which creates a meadow effect. Pervoskia can be managed by pruning any unwanted branches and to also maintain the plants structure. The pervoskia also has a history of being used for bringing temperatures down.