Introduced:  15th century
Class:  Alba
Zones:  to Zone 3
Parentage:  Uncertain
Flowers:  Pure white, semi-double, 8-12 petals.
Size:  6 to 10 feet
Fragrance:  Very fragrant
Strengths:  Excellent garden shrub:  free flowering, disease resistant, shade tolerant, good autumn hip display.

Also known as the 'White Rose of York', supposedly the emblem of the house of York in the fifteenth century War of the Roses, 'Alba semi-plena' is a strong choice for the garden.  Pure white flowers are complemented by yellow stamens, and they are approximately 3 1/2 inches wide.  Fragrance is excellent; 'Alba semi-plena' was one of two roses grown for the production of attar in the region famous for this oil, Kazanlik, Bulgaria.

A tall, spreading bush with arching canes, 'Alba semi-plena' is an excellent choice for the back of the border.  The attractive matte gray-green foliage is resistant to disease.  Be sure to leave the spent flowers on the shrub, and they will mature to attractive hips in the fall.

Alba roses tend to be somewhat shade tolerant, and 'Alba semi-plena' is consistent with this trait. Cold hardy to Zone 4, although there may be some dieback that far north.  Pruning should consist of cutting out dead wood after blooming, with the occasional hard pruning every couple of years to encourage fresh canes for next season.