Cranesbill (Geranium × oxonianum 'Thurstonianum')
Admire the reddish-purple blooms of Geranium × oxonianum 'Thurstonianum', a low-maintenance Cranesbill perfect for borders and shade.
Complete Plant Information
Overview
The Geranium × oxonianum ‘Thurstonianum’ is a highly valued herbaceous perennial, offering reliable color and structure to garden spaces. This specific Cranesbill hybrid is appreciated for its persistent blooming and relatively undemanding nature, making it a staple for intermediate borders and mixed plantings. Gardeners select this cultivar for its distinct reddish-purple flowers that reliably appear from early summer onward.
As a hybrid derived from $G$. Endressii and $G$. Versicolor, Geranium × oxonianum ‘Thurstonianum’ brings hybrid vigor to the garden while maintaining the classic charm of hardy true geraniums. It thrives across a decent temperature range, suitable for zones 5 through 8, providing dependable ground coverage or edging capabilities across the landscape.
This variety often presents lobed, dark green foliage, sometimes attractively blotched with chocolate markings, adding evergreen interest even when not in flower. Its low maintenance needs, coupled with its rabbit and deer resistance, make Geranium × oxonianum ‘Thurstonianum’ a practical and beautiful choice for extended seasonal interest in many garden settings.
Fast Facts
- Plant Family: Geraniaceae
- Plant Type: Herbaceous perennial
- Hardiness Zones: USDA Zones 5-8
- Size at Maturity:
- Height: 1.5-2 ft
- Spread: 1-1.5 ft
- Bloom Time: June to July
- Bloom Description: Reddish purple
- Sun Exposure: Full sun to part shade
- Water Needs: Medium
- Maintenance Level: Low
How to Grow
Planting the Cranesbill is easiest in the spring or fall, allowing it time to establish its root system before summer heat or winter cold sets in. The soil environment is crucial: aim for average, medium moisture, well-drained conditions. While this cultivar tolerates some drought once established, it performs best in humusy, moderately fertile soils that retain consistent moisture without becoming soggy.
During summer, routine care is straightforward. If grown in hotter climates, providing some part afternoon shade will prevent stress. In cooler northern regions, full sun exposure maximizes flower production for Geranium × oxonianum ‘Thurstonianum’. Watering should be consistent to support flowering, especially during dry spells.
The main cultural consideration is managing post-bloom aesthetics. While deadheading can encourage sporadic rebloom later in summer, it is often tedious for large areas. If the foliage begins to look tired or decline after the main flush in hot weather, simply cut the plant back to revitalize its appearance; new growth will emerge, sometimes followed by a second, smaller round of flowers. Propagation is reliably achieved through division of the established clumps.
Landscape Uses
Geranium × oxonianum ‘Thurstonianum’ excels as a versatile workhorse in mixed borders, working beautifully along the front edge where its compact habit won’t obscure shorter neighbors. Its ability to spread slowly makes it an excellent mass planting for creating naturalized ground cover effects beneath dappled shade trees or in open woodland settings.
For a classic cottage garden look, pair this Cranesbill with plants that share similar sun and moisture preferences, such as Peonies, Lady’s Mantle (Alchemilla mollis), or various Salvias. Its mounding form also makes it ideal for formal edging along pathways or driveways, providing a soft, green, and eventually flowering barrier. Consider using it in rock gardens, nestled between larger stones, where its foliage can spill gracefully over the edges.
Standout Features
Flower Qualities
- Showy
Noteworthy Characteristics
Geranium × oxonianum is a fertile hybrid between $G$. Endressii and $G$. Versicolor. The ‘Thurstonianum’ specific cultivar features 1.5” diameter, reddish purple flowers, notable for having 5 narrow, distinctively strap-shaped petals blooming from late spring into early summer. A charming feature of early blooms is the occasional production of petaloid stamens, which contribute a pleasing semi-double effect to the otherwise classic structure of the flower.
Tolerances
- Rabbit
- Deer
Potential Problems
Generally, this Cranesbill exhibits low vulnerability to pests and diseases. Gardeners should remain aware of a slight susceptibility to common fungal issues like leaf spots and rust, particularly when humidity is high or air circulation is poor. Maintaining good drainage and avoiding overhead watering late in the day can significantly reduce the risk of these issues developing on the foliage of Geranium × oxonianum ‘Thurstonianum’.
Frequently Asked Questions
What hardiness zones is Cranesbill suitable for?
The Geranium × oxonianum ‘Thurstonianum’ is adaptable to USDA Hardiness Zones 5 through 8, offering reliable overwintering capabilities in these regions.
How large does Cranesbill grow?
This variety typically matures to a height between 1.5 and 2 feet tall, with a spread ranging from 1 to 1.5 feet wide, forming a dense, clumping mound.
When does Cranesbill bloom?
The primary bloom time for Geranium × oxonianum ‘Thurstonianum’ is traditionally noted from June into July, presenting its signature reddish-purple flowers.
What sun exposure does Cranesbill need?
This plant performs well in a variety of conditions, thriving in full sun, though it benefits from partial shade during the hottest part of the afternoon in warmer climates.
Conclusion
The Geranium × oxonianum ‘Thurstonianum’ stands out as a robust and attractive perennial, offering dependable reddish-purple blooms and low-maintenance characteristics perfect for minimizing garden upkeep. Whether massed as ground cover or used as sharp edging, this beautiful Cranesbill earns its place in almost any perennial bed. Before planting, confirm that your growing area falls within USDA Zones 5-8 to ensure the best long-term performance.
Companion Planting
When planning the garden layout around your Geranium × oxonianum ‘Thurstonianum’, focus on pairing it with plants that share its medium water needs and tolerance for sun to part shade. Nepeta (Catmint) is an excellent companion, offering contrasting silvery foliage and a different floral color palette that harmonizes well with the reddish-purple of the Cranesbill. Hostas, particularly those with lighter green or variegated leaves, create lovely textural contrast beneath the canopy of deciduous trees where the geranium prefers a little afternoon relief.
Propagation Tips
One of the most straightforward ways to increase your stock of Geranium × oxonianum ‘Thurstonianum’ is through the simple division of its root clumps. This process is best undertaken in the spring before new shoots emerge vigorously or in the early fall as temperatures begin to moderate. Carefully lift the entire clump, teasing the roots apart to ensure each new section has sufficient roots and viable growth buds attached. Replant these divisions immediately into amended soil to help them re-establish quickly.
