A well-appointed garden needs not only flowers but also decorative foliage that is concurrently available to combine with the garden flowers in a vase.
Bright accents will make any blue/grey background plantings pop!
A lot of the best plant combinations in my yard have occurred without my conscious intervention.
Common garden sage, Salvia officinalis, is a staple in the herb garden and a plant for all seasons.
Grey, silver plants soften the landscape if used wisely.