Pink shower (Cassia × nealiae 'Wilhelmina Tenney')

Overview

The stunning Cassia × nealiae ‘Wilhelmina Tenney’, commonly known as Pink shower, is a highly valued hybrid tree prized for its exceptionally long bloom season. This cultivar offers a dazzling display of yellow and pink flowers, providing vibrant tropical color when many standard landscape trees are past their prime. Its sterile nature is a major advantage, ensuring abundant flowering without the persistent cleanup associated with unwanted seed dispersal.

Growing into a substantial specimen, Cassia × nealiae ‘Wilhelmina Tenney’ provides excellent overhead coverage, making it a superb choice for broad landscapes. It thrives in bright, full sun conditions and exhibits moderate drought tolerance once fully established. Gardeners seek out this specific variety for its reliability and magnificent, shower-like floral presentation throughout the warmer months.

This tree is a cross between the golden shower tree and the pink-and-white shower tree, inheriting the best traits from both parents. Its value lies not only in its beauty but also its functional use as a shade provider in warm climates, cementing the Pink shower’s reputation as a premier ornamental focal point.

Fast Facts

• Plant Family: Fabaceae
• Plant Type: Tree
• Hardiness Zones: USDA Zones 10-12
• Size at Maturity:
  • Height: 30-50 ft
  • Spread: 20-40 ft
• Bloom Time: April to September
• Bloom Description: Yellow and pink
• Sun Exposure: Full sun
• Water Needs: Medium
• Maintenance Level: Medium

How to Grow

Planting the Pink shower should occur when soil temperatures are warm, ideally in spring after the risk of frost has completely passed, ensuring optimal establishment for this tropical hybrid. Cassia × nealiae ‘Wilhelmina Tenney’ requires full sun exposure to maximize flower production and establish a dense canopy. It performs best in average, medium-moisture soils that drain effectively, as stagnant water can inhibit root growth.

Once established, this tree develops moderate drought tolerance, though consistent watering is recommended during prolonged dry spells to support vigorous growth and flowering. Site your Cassia × nealiae ‘Wilhelmina Tenney’ where it is protected from strong, desiccating winds, which can cause stress and premature leaf drop. Because this is a sterile hybrid, propagation requires specific techniques; grafting or air layering are the preferred methods to ensure you reproduce the desirable yellow and pink flower characteristics of ‘Wilhelmina Tenney’.

Pruning should be minimal, focusing primarily on removing dead or crossing branches to maintain its natural, spreading form. Be aware that the tree may experience a brief period of leaf drop, typically in March or April, preceding the main flush of blooms, making it appear semi-deciduous during that short window.

Landscape Uses

The significant dimensions of Cassia × nealiae ‘Wilhelmina Tenney’—reaching up to 50 feet tall and 40 feet wide—make it an unparalleled choice for use as a grand shade tree in tropical and subtropical landscapes. Its vast canopy offers welcome relief during hot summers, positioning it perfectly over large lawns, patios, or along wide avenues where its flowering impact can be fully appreciated.

As a formal street tree, the Pink shower excels, often replacing less resilient species in urban environments, particularly in Honolulu where it is already designated as the official city tree. When used in expansive ornamental settings, group it with other drought-tolerant, warm-climate flowering trees, perhaps contrasting its softer pinks and yellows with deeper red or purple bloomers for visual depth. Its airy foliage and spectacular blossoms ensure that Cassia × nealiae ‘Wilhelmina Tenney’ functions as a powerful vertical accent or a spectacular specimen planting.

Standout Features

Flower Qualities

• Showy
• Fragrant

Noteworthy Characteristics

Cassia × nealiae, commonly called rainbow shower tree, is a hybrid cross between C. Fistula (golden shower tree) and C. Javanica (pink-and-white shower tree). It typically grows to 30-50’ tall and is noted for producing a show-stopping bloom of lightly-scented, 5-petaled flowers in 8-12” pendant racemes from April to September, often being semi-deciduous before flowering. Advantages of this hybrid include its sterility, resulting in better and more abundant flowering than either parent, and its clean habit due to producing few seed pods. The specific ‘Wilhelmina Tenney’ form, renowned for its yellow and pink coloration, was named after the individual who donated an offspring to the Foster Botanical Garden.

Tolerances

• Drought

Potential Problems

This hybrid tree generally enjoys a low risk profile concerning pests and diseases, though gardeners should remain vigilant for common fungal issues like mildew and leaf spot, which can sometimes appear. To manage these, ensure good air circulation around the canopy and avoid overhead watering, especially in humid conditions. The plant has a limited tolerance for cold snaps, surviving brief dips down to approximately 25°F, but hard frosts must be avoided to prevent serious damage. Remember that Cassia × nealiae ‘Wilhelmina Tenney’ is sterile, necessitating propagation via grafting or air layering to maintain its specific desirable traits.

Frequently Asked Questions

What hardiness zones is Pink shower suitable for?

The Pink shower, or Cassia × nealiae ‘Wilhelmina Tenney’, is suitable for warm climates, specifically USDA Hardiness Zones 10 through 12.

How large does Cassia × nealiae ‘Wilhelmina Tenney’ grow?

This tree matures into a substantial size, typically reaching heights between 30 and 50 feet, with a broad spread ranging from 20 to 40 feet wide.

When does Pink shower bloom?

The spectacular flowering period for Cassia × nealiae ‘Wilhelmina Tenney’ extends from April all the way through September, featuring beautiful yellow and pink blossoms.

What sun exposure does Pink shower need?

For optimal health and the most abundant flowering, the Pink shower requires full sun exposure throughout the day.

Conclusion

The Cassia × nealiae ‘Wilhelmina Tenney’ is an outstanding horticultural specimen, delivering extended periods of fragrant, showy blooms and substantial shade making it invaluable in its suitable climates. This reliable hybrid, the Pink shower, offers superior performance over its parent species. Before planting, confirm your garden resides comfortably within USDA Zones 10-12 and that you can provide a full sun location.

Companion Planting

Selecting companions for Cassia × nealiae ‘Wilhelmina Tenney’ involves choosing other species that share its preference for heat, full sun, and well-draining soil typical of tropical or semi-tropical environments. Because the Pink shower becomes a large canopy tree, underplantings should utilize smaller shrubs or groundcovers that appreciate partial shade during the hottest part of the day, or sun-lovers that won’t compete heavily for subsurface water. Consider pairing it with subtropical bloomers like vibrant bougainvillea or structural plants such as various palms that complement its grand scale without shading out its lower branches excessively. When planting near walkways, remember the periodic leaf drop in early spring requires considering materials below that are easy to sweep or rake.

Design Ideas: Creating a Tropical Focal Point

Utilizing the Pink shower as a specimen tree capitalizes on its inherent drama and impressive stature. Site Cassia × nealiae ‘Wilhelmina Tenney’ prominently where its later summer color provides crucial visual interest when many other annuals are fading. Its height allows it to anchor a large tropical-themed border, acting as the backdrop against which smaller, richly textured foliage plants can play. For sweeping vistas along driveways or large properties, planting in staggered groups of odd numbers creates a natural, flowing rhythm thanks to the tree’s characteristic umbrella-like crown structure.