Bean tree (Laburnum × watereri 'Vossii')
Laburnum × watereri 'Vossii', the spectacular Bean tree, offers stunning yellow, wisteria-like blooms in late spring. Ideal for zones 5-7.
Complete Plant Information
Overview
The Laburnum × watereri ‘Vossii’, commonly known as the Bean tree, is highly valued in temperate landscapes for its extravagant display of pendulous, bright yellow flowers resembling wisteria, which drape beautifully in late spring. This hybrid golden chain tree results from crossing L. Alpinum and L. Anagyroides, yielding a magnificent specimen tree noted for its profuse, spectacular bloom period in May and June. While it requires specific regional suitability, the resulting low-maintenance specimen offers significant ornamental return, making the Laburnum × watereri ‘Vossii’ a showpiece when sited correctly.
This deciduous tree typically matures between 15 and 30 feet tall, featuring clover-like, medium green foliage that provides a simple backdrop for the golden flowers. Gardeners must recognize that while the flowers are stunning, all parts of the Bean tree are poisonous, requiring careful placement away from high-traffic areas or curious pets and children. Its best performance is achieved in moderate climates, offering spectacular value to those situated within its appropriate USDA hardiness zones.
Fast Facts
- Plant Family: Fabaceae
- Plant Type: Tree
- Hardiness Zones: USDA Zones 5-7
- Size at Maturity:
- Height: 15-30 ft
- Spread: 15-30 ft
- Bloom Time: May to June
- Bloom Description: Yellow
- Sun Exposure: Full sun to part shade
- Water Needs: Medium
- Maintenance Level: Low
How to Grow
The key to successfully growing Laburnum × watereri ‘Vossii’ involves selecting a location that respects its environmental needs, especially avoiding the harsh heat and humidity of the deep South (below Zone 7). Plant this specimen tree in organically rich, medium-moisture, well-drained soils. While it prefers full sun for the best flower production, it benefits significantly from partial afternoon shade in very hot summer climates.
Routine care for the Bean tree is relatively low maintenance. Water consistently to maintain medium soil moisture, especially when young. Pruning requirements primarily focus on structural training if desired as a small tree; in these cases, be diligent about removing any developing root suckers immediately. This particular cultivar, Laburnum × watereri ‘Vossii’, often produces fewer seedpods than its parent species, but removal of any seedpods that do form is recommended, as they are not ornamental and contribute to the plant’s toxicity.
For gardeners in cooler areas like St. Louis, site the Laburnum × watereri ‘Vossii’ in a protected spot to shield it from damaging sub-zero winter temperatures. Those in the Pacific Northwest, where temperatures are comparatively moderate year-round, generally see the best overall performance from this species. Proper initial siting minimizes the need for intensive cultural intervention later.
Landscape Uses
The dramatic, cascading flowers make the Bean tree an exceptional choice for use as a small specimen tree, drawing the eye across the garden in late spring. Beyond its role as a standalone focal point, Laburnum × watereri ‘Vossii’ offers versatility; it can be managed as a large shrub or trained artfully against vertical structures such as arbors, pergolas, or espaliers to maximize the visual impact of the hanging racemes.
Its vibrant yellow hue serves as an excellent, bold background plant, contrasting beautifully against darker green evergreens or deep purple foliage plants. Consider grouping the flowering tree away from edible production areas due to its inherent toxicity. When training against supports, ensure the structure is robust enough to bear the weight of the mature wood and the dense spring flower load of this gorgeous specimen.
Standout Features
Flower Qualities
- Showy
Noteworthy Characteristics
Laburnum × watereri, commonly called golden chain tree, is noted for its pendulous axillary racemes of yellow, wisteria-like flowers that bloom in spring. This hybrid is a cross between L. Alpinum and L. Anagyroides. It typically grows 25-30’ tall as a tree, and 15-20’ tall as a shrub. Trifoliate, clover-like, medium green leaves (to 3” long) produce little fall color. Pea-like yellow flowers in racemes to 15” long appear in a profuse, often spectacular, late spring bloom. Flowers give way to seedpods that ripen in the fall. This hybrid usually produces a sparser crop of seedpods that its parents. Genus name is the Latin name. ‘Vossii’ is a cultivar that produces pea-like yellow flowers in drooping racemes to 24” long in a profuse and often spectacular late spring bloom.
Potential Problems
Twig blight is an infrequent but potentially serious disease. Canker and leaf spot are lesser disease problems. Gardeners should monitor regularly and watch for infestations of aphids and mealybugs, treating promptly with appropriate horticultural oils or insecticidal soaps if necessary to keep the foliage healthy and vibrant.
Tolerances
(No data provided)
Frequently Asked Questions
What hardiness zones is Bean tree suitable for?
The Laburnum × watereri ‘Vossii’ is generally suitable for USDA Hardiness Zones 5 through 7.
How large does Laburnum × watereri ‘Vossii’ grow?
This tree typically reaches a mature height between 15 and 30 feet, with an equivalent spread of 15 to 30 feet.
When does Bean tree bloom?
The Bean tree features its spectacular bloom time from May to June, displaying profuse yellow flowers.
What sun exposure does Laburnum × watereri ‘Vossii’ need?
For optimal health and flowering, the Laburnum × watereri ‘Vossii’ requires full sun to part shade, though afternoon shade is appreciated in the hottest climates.
Conclusion
The visual splendor provided by the cascading yellow blooms ensures that the Bean tree remains a highly desirable, though regionally specific, addition to the garden. By respecting its moderate climate preferences and minimal maintenance needs, landowners can enjoy the spectacular late spring show of Laburnum × watereri ‘Vossii’. Always confirm that your local climate falls within USDA Zones 5-7 before planning to plant this elegant flowering specimen.
Companion Planting
Choosing appropriate companions is crucial to accent the golden display of the Bean tree while managing soil and light consistency. Since Laburnum × watereri ‘Vossii’ prefers rich, well-drained soil and appreciates afternoon shade, pairing it with spring-flowering bulbs that die back before the tree leafs out fully can be very effective. Consider early-blooming perennials like Hepatica or woodland phlox (Phlox divaricata), which thrive in dappled sun conditions similar to those tolerated by the tree.
For year-round structure that complements the deciduous nature of the Laburnum × watereri ‘Vossii’, utilize evergreen shrubs with contrasting foliage color, such as deep purple smokebush (Cotinus coggygria selections) or dark green rhododendrons that can tolerate the filtered light beneath the canopy. Avoid planting aggressive root systems too closely, as the tree prefers its medium moisture soil undisturbed.
Seasonal Care Calendar
Spring is the critical time for enjoying the Bean tree; ensure that any structural pruning or removal of suckers is conducted immediately after flowering has finished to avoid cutting off next year’s blossoms. As summer arrives, monitor soil moisture closely, supplementing water during dry spells to satisfy its medium water needs, especially if grown in full sun.
During fall and early winter, inspect the tree for signs of canker or twig blight, removing any dead or diseased wood promptly to maintain vigor leading into dormancy. While the tree is hardy to Zone 5, protect young specimens in colder reaches by applying a layer of mulch around the root zone after dormancy is well-established, avoiding direct contact with the trunk.
