Culture
Grow in medium moisture, slightly acidic, well-drained garden loams in full sun. Best flowering and disease resistance generally occur in full sun. 'Veilchenblau' has some tolerance for part shade. Water deeply and regularly (mornings are best). Avoid overhead watering. Good air circulation promotes vigorous and healthy growth and helps control foliar diseases. Summer mulch helps retain moisture, keeps roots cool and discourages weeds. Remove spent flowers to encourage rebloom. Crowns appreciate winter protection in cold winter areas such as St. Louis. Remove and destroy diseased leaves from plants, as practicable, and clean up and destroy dead leaves from the ground around the plants both during the growing season and as part of a thorough cleanup during winter (dormant season). Avoid pruning for the first 3 years after planting so that the canes can properly develop. Canes must be hand-fastened to a support structure. Prune thereafter as needed (i.e., remove diseased or injured branches and prune out any poorly flowering canes) in late winter to early spring.
Noteworthy Characteristics
Rosa is a genus of about 150 species of deciduous (occasionally evergreen) shrubs and climbers noted for their beautiful, often fragrant, single, semidouble or double flowers which are borne singly or in clusters on often prickly stems clad with 5-9 leaflets often having toothed margins.
Ramblers are similar to climbers, producing long stems requiring support. Most bloom just once in spring. They are noted for producing several new shoots from the base of the plant allowing for older stems to be regularly removed and the plant regenerated. Ramblers also tend to be larger than climbers, requiring more space.
Genus name comes from the Latin name for rose.
'Veilchenblau’ ('Crimson Pirate' x 'Souvenir de Brod') is a hybrid multiflora rose that typically rambles to 10-15'. It is particularly noted for producing almost blue flowers (veilchenblau in German means violet). Small, cupped, mildly-fragrant, semi-double (9-12 petals each) purple-crimson-violet roses (each to 1 1/2" across) with showy golden stamens bloom in large clusters (10-30 flowers each) in May-June on nearly thornless canes clad with fresh medium green leaves. Flowers fade to gray-lilac. No repeat bloom. 'Veilchenblau' is synonymous with and sometimes sold in commerce as 'Blue Rambler', 'Blue Rosalie' or 'Violet Blue'. J. C. Schmidt 1909.
Problems
Roses are susceptible to a large number of diseases, the most common of which are black spot, powdery mildew, rust and rose rosette. Although good cultural practices are the first line of defense in disease control, regular preventative fungicide applications throughout the growing season are usually required, particularly in humid climates with regular summer rainfall such as the St. Louis area. Potential insect problems include aphids, beetles, borers, scale, thrips, rose midges, leafhoppers and spider mites. Local rose associations and extension services are usually able to offer specific recommendations and advice for selecting and growing roses.
Uses
Large-flowered rambling climber for walls, arbors, trellises, fences, pillars, pergola and around pillars.