Rosa rugosa 'Alba'

Common Name: Japanese rose 
Type: Deciduous shrub
Family: Rosaceae
Zone: 3 to 8
Height: 4.00 to 6.00 feet
Spread: 3.00 to 5.00 feet
Bloom Time: June to August
Bloom Description: White
Sun: Full sun to part shade
Water: Medium
Maintenance: Medium
Suggested Use: Hedge
Flower: Showy, Fragrant
Leaf: Good Fall
Attracts: Butterflies
Other: Thorns
Tolerate: Clay Soil, Air Pollution

Culture

Best grown in moist, slightly acidic, well-drained garden loams in full sun to part shade, but this rose is also very adaptable to somewhat poor soils, including sandy, clay or gravelly ones. Best flowering and disease resistance generally occur in full sun. Water deeply and regularly (mornings are best). Avoid overhead watering. Excellent drainage is one of the keys to growing this shrub well. Avoid wet soils. 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 (flower removal does prevent hip growth). 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. This rose is winter hardy to USDA Zone 2 where temperatures can dip to -50 degrees F. in winter. It has escaped plantings and naturalized in at least nineteen states (mostly in the northeast and central U. S.). Inland, it has escaped gardens, often being found along roadsides and railroad right of ways. Along the Atlantic coast (Maine to Virginia) and Great Lakes regions it grows exceedingly well in sand and has over time naturalized in dry sandy/gravelly coastal plains, sandy beaches and sand dune habitats (giving rise to additional common names of beach rose and salt spray rose). It can be invasive in some areas (particularly New England coastal areas). It is very tolerant of salt spray. Seeds are spread not only by birds and animals, but also in coastal areas by seawater.

Noteworthy Characteristics

Rosa rugosa is native to northern China, Korea and Japan. It is a bristly, prickly, sprawling, suckering shrub rose that typically grows in a rounded form to 4-6' tall and as wide. Unless restrained, it will over time spread by suckers to form dense thickets. Odd-pinnate dark green leaves (each with 5-9 leaflets) turn yellow (sometimes a quality orange-red) in fall. Each leaflet (to 2" long) has pronounced veins, a wrinkled appearance, serrated edges and downy undersides. Fragrant flowers are rose pink to white (to 3 1/4" across). Flowers are primarily single (5 petals), but are semi-double or double in some varieties and hybrid cultivars. Flowers appear singly or in clusters. Flowers primarily bloom from late May to July, with some additional scattered bloom to early fall. Flowers are followed by fleshy, edible (with some bitterness), tomato-shaped hips (to 1" diameter) which appear green but ripen to bright red by late summer and persist on the shrub until late fall sometimes extending into winter. Hips are used to make jams and jellies (rose hip jam). Deadheading spent flowers may encourage rebloom, but at the cost of preventing rose hip development. Stems are covered with abundant sharp thorns, making this an excellent impenetrable hedge. Ability to thrive in sandy seashore habitats combined with tomato-shaped hips led to the additional common names of beach tomato and sea tomato for this shrub. Because of its tolerance for salt and sand, this rose has been planted along ocean shores to help stabilize beaches/control beach erosion. Many varieties and hybrid cultivars (single to double flowers in colors of pink, purple or white) have been developed.

Genus name comes from the Latin name.

Specific epithet means wrinkled in reference to the appearance of the foliage.

'Alba' is a white sport of R. rugosa. It is a dense, upright, rounded shrub which typically grows 4-6' tall and 3-5' wide. Features fragrant, pure white, single flowers (to 3.5" across). Blooms profusely from late spring to late summer. Glossy, leathery, dark green foliage turns attractive shades of yellow, orange and red in fall.

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.

Rosa rugosa, however, is noted for having excellent disease resistance.

Garden Uses

Hedge (impenetrable due to abundant sharp thorns). Screen. Specimen. Banks. Cottage gardens. Sandy soils. Beaches/dunes for erosion control. Avoid planting in small garden areas where suckering spread will become a problem.