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.
I. Appearance and Characteristics
Get in on the geranium of the millennium, as marketers have called Geranium Rozanne. This perennial bloomer is a type of cranesbill geranium. The moniker hails from the Greek, where geranium means crane. The cranesbill reference is to the geranium seed capsule, which has a long beak-like column. Rozanne geranium is a sterile hybrid and doesn’t produce seeds, but its heritage includes other cranesbill geraniums.
Rozanne geranium was discovered in a home garden in Somerset, England. It’s the result of a natural cross between two blue-flowered cranesbill geraniums: Geranium himalayense and Geranium wallichianum ‘Buxton’s Variety.’ The resulting geranium boasts larger blooms, greater heat tolerance and a longer flowering window than its parents or other cranesbill geraniums.
Flowers on Rozanne geranium almost glow in the garden, opening in a vibrant violet-blue shade. The center of each blossom has a white eye. Darker violet-blue lines run along petals, serving as nectar guides for pollinating insects. Rozanne geranium opens its 2.5-inch-wide flowers non-stop from late spring to early fall. In regions with mild winters, gardeners report smatterings of blooms as late as December.
Leaves also offer some sparkle on this geranium. They have a traditional cranesbill geranium appearance with deep lobes, but these leaves boast marbling in shades of chartreuse. In fall, foliage shifts to red and bronze hues, adding more color to the garden.
Rozanne geranium grows roughly 20 inches tall and spreads 24 to 28 inches wide. Unlike other cranesbill geraniums, Rozanne doesn’t necessarily form a neat mound. Instead, it rambles through the garden, clambering up and over other plants. If rambling stems feel overbearing, simply cut them back at any time during the growing season to as short as you like. The plant will respond by branching and possibly blooming.
II. How to Grow and Care
Sunlight
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.
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.
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.
Fertilizing
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
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.
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.
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.
Pests and Diseases
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.
Common 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.
Common 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.
III. Uses and Benefits
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.
