Culture
Best grown in medium moisture, slightly acidic, well-drained garden loams in full sun to very light shade. Best flowering and disease resistance generally occur in full sun, however. 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 need 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). Prune as needed in late winter to early spring.
Avoid pruning for the first two years after planting to allow the canes of this climber to develop.
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.
Climbing roses usually need support by securing to a pillar, fence or wall but some can be grown more as a shrub. Some are also suitable as a groundcover. Many rebloom throughout summer but some flower just once in spring.
Genus name comes from the Latin name for rose.
'Don Juan' is a large-flowered climbing rose that typically grows 8-10' tall. Features very fragrant, dark red, double flowers (to 5" across). Blooms late spring to frost. Glossy, leathery, dark green foliage.
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
One of the best of the red climbers. Excellent as a pillar rose. Also effective on walls, arbors, white fences or other structures.