Shrub dogwoods (Cornus species) have become very popular in recent years for their low maintenance and attractive, four-season appeal. Popular in commercial and residential landscapes, many varieties have beautiful spring flowers, attractive summer foliage with good autumn color, and brightly colored winter bark. Longwood Gardens, in Pennsylvania, conducted a five-year variety trial to determine which dogwood species and varieties performed the best. Thirty-three shrubs were grown in full sun in a seven-acre area at these USDA zone 6 gardens and evaluated by the horticultural staff. Little maintenance was done to the plants other than mulching, occasional watering, and pruning each shrub back to a height of 12 inches each spring.
Of the naturally occurring species, Cornus sericea coloradensi was the highest rated for its rounded form, long bloom time, and rose-colored stems. C. racemosa scored second highest for its dense growth and bright foliage and fruits.
Of the varieties developed by plant breeders, variegated-leaved C. alba 'Argenteomarginata' scored highest for its disease resistance, good flowering habit, and attractive winter bark color. C. alba 'Bud's Yellow', C. alba 'Flaviramea', and C. alba 'Midwinter Fire' were the highest rated yellow-twigged dogwoods. C. alba 'Siberica' and C. seriacea 'Baileyi' were the highest rated red-twigged varieties.
For more information on this trial, go to: Longwood Gardens