Bloombux® as a Boxwood Alternative: Long-Term Trial by the LVG Bad Zwischenahn Confirms the Strengths of the Dwarf Rhododendron

Bloombux® convinces – now scientifically proven

For many years, the Horticultural Teaching and Research Institute (LVG) in Bad Zwischenahn-Rostrup has been testing alternatives to boxwood under practical conditions for use in low hedges. The main focus is on which woody plants are suitable as substitutes for the boxwood—plagued by pests and diseases—in terms of winter hardiness, susceptibility to pests and diseases, hedge density and growth vigour. As one of the few flowering evergreen alternatives, the INKARHO®-bred Rhododendron Bloombux® has proven its worth.

The LVG is now conducting its third study on boxwood alternatives. The current trial was established in 2015. In total, fifty different alternatives—deciduous and coniferous shrubs as well as perennials—are being tested. One-metre-long hedge elements were planted with three replications each and are pruned twice a year, in July and October, to about 20 cm in height and width. The evaluation covers growth rate, hedge density, and abiotic and biotic damage. Owing to the increasingly severe problems with boxwood, the trial has attracted great interest across the horticultural sector.

“Overall, Bloombux® showed positive results and proved to be a practical alternative to boxwood,” explains Björn Ehsen, who has supervised the trials at LVG since the beginning. From the outset, Bloombux® impressed with its uniform growth and high suitability for trimming. The dwarf rhododendron also performed well thanks to its lime tolerance, winter hardiness and abundant flowering in June. Bloombux® proved effective not only as a low hedge but also as ground cover, demonstrated at the adjacent ‘Park der Gärten’ in Bad Zwischenahn. It can also be used as a half-sphere or in containers, although this was not tested in the trial. However, there are some limitations, as Ehsen points out: “Bloombux® is a rhododendron and has specific site requirements. Adequate nutrient supply is essential, and a sunny to semi-shady location with humus-rich, well-drained soil should be chosen. If these conditions are met, Bloombux® is definitely a worthy alternative.”

Since site conditions vary considerably across Germany, long-term trials were also conducted at other locations. Bloombux® again performed reliably: at the LVG Erfurt it was rated a “recommended alternative” when its site requirements were respected, and at the LfULG Dresden-Pillnitz it also achieved good overall results. Similarly, the dwarf rhododendron convinced in a demonstration planting by the Chamber of Agriculture of Lower Saxony in Hanover-Ahlem, where various plants were tested for their suitability in grave planting under full sun exposure. These results clearly show that Bloombux® remains reliable even under drier, sunnier conditions.

For consumers and the trade, Bloombux® now stands as a proven boxwood alternative. It combines the traditional use of boxwood with insect friendliness, site flexibility, and additional floral appeal. The results of the long-term LVG Bad Zwischenahn trial, together with those from other research sites, confirm that Bloombux® represents a reliable long-term choice for garden centres, landscape professionals, and their clients.

FURTHER INFORMATION
About INKARHO®
The INKARHO® (Interest Group of Lime-Tolerant Rhododendrons) has been firmly established in the market for over 25 years. Fifteen nurseries produce a wide range of robust rhododendron varieties—from compact hedge plants such as Bloombux® to large-flowered hybrids. All share outstanding site tolerance, strong roots, healthy foliage, and abundant blossoms.

About the LVG Bad Zwischenahn
The Horticultural Teaching and Research Institute (LVG) Bad Zwischenahn-Rostrup is located in the heart of the Ammerland, one of Europe’s most important horticultural regions. As a centre of expertise for ornamental plants and nursery production, it conducts practical research and supports the horticultural profession in northern Germany and beyond through advice and knowledge transfer.