For a combination that last all through the growing season consider blue oat grass ‘Saphirsprudel’ and Sedum ‘Autumn Joy’. The pair get going early in spring as new growth emerges. The blue-green color of the fleshy leaves of Sedum ‘Autumn Joy’ echo the color of the thin blades of blue oat grass ‘Saphirspurdel’ but contrast in shape and texture. As the season progresses Sedum ‘Autumn Joy’ produces tiny green buds that slowly open to pink before turning brick red in the fall. The pink color and fuzzy texture of the flowers provide further contrast with blue oat grass ‘Saphirsprudel’. Winter interest is provided by the foliage of blue oat grass ‘Saphirsprudel’ and the flowerheads of Sedum ‘Autumn Joy’ that dry on the plants and persist. Grow in full sun and medium-moist, well-drained soil.
Blue Oat Grass (Helictotrichon sempervirens) ‘Saphirsprudel’
This tufted evergreen grass, also sold as ‘Saphire’, is similar to Festuca glauca although larger. It has stiff silvery blue-green leaves and flower spikes that are straw-yellow tinted with purple when mature. The species could be used in the combination too but is not as blue and is less tolerant of heat and humidity. Best color develops when grown in relatively dry soil. Foliage should be cut down in late winter.
Bloom Time: Early summer
Size: 24-36” H x 18-24” W
Hardiness: Zones 4-8
Sedum ‘Autumn Joy’
Providing garden interest all season long, Sedum ‘Autumn Joy’ is one of the most valuable plants you can have in a perennial garden. The flowers are borne in flat flowerheads three to six inches across on dense upright plants with succulent stems and leaves. Not only does ‘Autumn Joy’ look good from early spring into fall and winter, it is attractive to butterflies, easy to grow, and drought and heat tolerant once established.
Bloom Time: Summer to fall
Size: 18-24” H x 18-24” W
Hardiness: Zones 3-9.