Geranium Rozanne (Cranesbill)

Geranium Rozanne is an exceptional, unique, and unsurpassed geranium selection. There are not enough superlatives to describe this fabulous perennial. Robust and vigorous, with one of the longest flowering periods of all hardy geraniums and rare blue-colored flowers of great decorative beauty, it is an ideal element of the garden, patio, or balcony.

Geranium Rozanne – Cranesbill: An In-depth Look

Geranium Rozanne is an award-winning perennial that offers continuous color and reliable performance in a variety of garden settings. It is celebrated for its large, vivid violet-blue flowers with white centers and striking veining. The blooms contrast beautifully against the plant’s lightly marbled, deep green foliage. Its hardiness, ease of care, and beautiful, long-lasting blooms make it a favorite among gardeners and a standout in perennial gardens.

Native: This plant is a cultivar and does not have a specific native range. It was discovered in a garden in Somerset, England, making it a product of horticultural breeding rather than a species from a specific geographic area. It belongs to the Geraniaceae family, which includes both the genus Geranium (the cranesbills, or true geraniums) and the genus Pelargonium (garden plants called geraniums), along with other related genera.

Plant Type and Habit: Geranium Rozanne is a herbaceous perennial with a sprawling habit. It is known for its vigorous growth and ability to fill in spaces without overwhelming neighboring plants.

Size: This geranium typically reaches about 20 inches (50 cm) in height and can spread up to 24-36 inches (60-90 cm), forming a dense mat that effectively suppresses weeds. Reliable, Rozanne comes back year after year, bigger and even better than the previous spring.

Flowers: Geranium Rozanne continuously produces a profusion of large, saucer-shaped blooms measuring up to 2 inches (5 cm) across. The flowers are a striking violet-blue with white centers and purple-violet veins, providing a long-lasting display of color. Geranium Rozanne has one of the longest blooming periods of any of the hardy geraniums, flowering profusely from late spring to the first frost in autumn.

Foliage: The foliage is slightly marbled with deep green and chartreuse tones and maintains its attractiveness throughout the growing season, turning reddish-brown in fall.

Hardiness: It is hardy in USDA zones 5 through 8, making it suitable for a wide range of climates. Rozanne is also exceptionally heat-resistant.

Awards: Worldwide acclaimed, it is the recipient of the prestigious Award of Garden Merit of the Royal Horticultural Society (2006) and the winner of the Plant of Year award (2008). It has also been voted one of the top ten best Plants of the Centenary (RHS Chelsea Flower Show).

Uses: Geranium Rozanne is extremely versatile in the landscape, suitable for use in borders, rock gardens, as underplanting for shrubs and roses, or in containers. Its long blooming season and sprawling habit make it excellent for filling gaps and providing continuous summer color. It is also an excellent choice as a ground cover or in mass plantings, where it provides excellent color contrast.

Pollinators: The flowers attract bees and butterflies, making it a useful addition to pollinator gardens.

Deer and Rabbits: It is generally resistant to deer and rabbits, which tend to avoid it due to its aromatic foliage.

Toxicity: Geranium Rozanne is not known to be toxic to humans or pets, making it a safe choice for gardens frequented by children and animals.

Drought Tolerance: While it prefers moist, well-drained soil, Rozanne is relatively drought-tolerant once established, making it suitable for gardens in drier climates.

Invasiveness: Unlike some geraniums, Rozanne does not have aggressive self-seeding behavior and is not considered invasive. Its growth is vigorous but manageable.

Benefits: One of the main benefits of planting Geranium Rozanne is its long flowering period, low maintenance, and its ability to attract pollinators while resisting pests and diseases.

How to Grow and Care for Rozanne Geranium

When to Plant: The best times to plant Rozanne Geranium are in the spring or early fall. This timing allows the plant to establish itself during mild weather.

Light: Choose a location that receives full sun to partial shade. While Rozanne can tolerate a range of light conditions, more sun leads to more blooms.

Soil: Rozanne Geranium thrives in well-drained soil. It can adapt to various soil types but performs best in soil that is fertile and moist. If your garden soil is heavy clay or very sandy, amend it with compost or peat moss to improve drainage and nutrient content.

Watering: Water regularly to keep the soil evenly moist, especially during the first growing season to establish a deep, extensive root system. Once established, Rozanne Geranium is relatively drought-tolerant but will perform best with consistent moisture. Avoid Overwatering: Ensure good drainage to prevent waterlogged conditions, which can lead to root rot.

Fertilization: Feed Rozanne Geranium in early spring with a balanced, slow-release fertilizer to support vigorous growth and abundant flowering. Additional feeding may be beneficial in midsummer, especially if plants appear lackluster or growth has stalled.

Pruning and Maintenance: Although not necessary for continued blooming, removing spent flower heads can tidy up the plant and may encourage additional blooming. Cut back the entire plant to ground level in late autumn or early winter after the foliage and flowers have died back. This will help promote vigorous growth in the spring.

Mulching: Apply a layer of organic mulch around the base of the plant to help retain soil moisture, suppress weeds, and provide winter protection.

Winter Care: In colder regions (USDA zones 4 and sometimes 5), additional winter protection may be beneficial. Mulch heavily around the crown of the plant after the ground freezes to prevent freeze-thaw cycles that can heave the plant out of the soil.

Propagation: Rozanne Geranium can be propagated by division in early spring or fall. This is also a good opportunity to rejuvenate older plants that may have become woody or less vigorous.

Geranium Rozanne: Pests, Diseases, Common Problems

Geranium Rozanne is a robust and resilient plant. However, like all plants, it can encounter some pests and diseases, though generally, it faces fewer problems than many other garden varieties.

Pests

Aphids: These small sap-sucking insects can cluster on the new growth, weakening the plant. Aphids are particularly attracted to lush, new foliage. They can often be managed by spraying them off with a strong jet of water or by using insecticidal soap or neem oil if infestations become severe.

Slugs and snails: They are fond of the leaves, especially in damp conditions, and can cause significant damage by chewing holes in the foliage. Manual removal, barriers such as diatomaceous earth, or environmentally friendly baits can be effective.

Diseases

Root rot: Overwatering and poorly draining soils can lead to root rot, which can severely impact plant health. Prevention is best managed by ensuring good soil drainage and moderating watering practices to prevent waterlogged conditions.

Powdery mildew: This fungal disease appears as a white powdery coating on leaves and stems, particularly during hot, humid weather or in overly dry conditions. Powdery Mildew can be controlled by improving air circulation around the plants and reducing overhead watering. Fungicidal sprays can also be used as a preventive measure during known high-risk periods.

Common Problems

Leaf Spot: Occasionally, bacterial or fungal leaf spots may appear, especially in wet conditions.

Yellowing Leaves: Overwatering, poor drainage, or nutrient deficiencies can cause leaves to turn yellow.

Leggy Growth: If Rozanne does not receive enough sunlight, it may become leggy as it stretches toward the light.

Fading Color: Intense afternoon sun can sometimes cause the vibrant blue flowers to fade.

Frequently Asked Questions

Companion plants for Rozanne geranium?

Geranium Rozanne pairs beautifully with a variety of other plants, including salvia, lavender, Shasta daisy, hosta, catmint, and grasses.

Does geranium Rozanne like sun or shade?

Geranium Rozanne performs best in full sun to partial shade. While it can tolerate a range of light conditions, it flowers most abundantly in full sun. In very hot climates, some afternoon shade is beneficial to prevent the leaves from scorching.

Does Rozanne geranium spread?

Rozanne is known for its vigorous growth habit. It can spread up to 2-3 feet (60-90 cm) wide, creating a beautiful ground cover. It does not grow invasively, but its healthy sprawl can fill in garden spaces effectively.

Do you cut back Rozanne geraniums in the fall?

Typically, Geranium Rozanne does not require cutting back in the fall as it can provide winter interest with its foliage. However, in spring, it is beneficial to cut back the entire plant to ground level to promote fresh, vigorous growth and maintain a tidy appearance.

Where is the best place to plant geranium Rozanne?

The best place to plant Geranium Rozanne depends on a few factors:
Light: As mentioned, it thrives in full sun to partial shade.
Soil: Plant in well-draining soil to prevent waterlogging and root diseases.
Space: Allow room for its spread, making it ideal for borders, ground covers, or as underplanting for shrubs and roses.
Aesthetic: Plant where its long blooming season can be appreciated, such as near patios, walkways, or garden edges.