Hillier says The UK has a fantastic, thriving, horticultural industry but when it comes to the development of new and improved tree cultivars and clones however, some architects, designers and landscape contractors are still looking outside our borders for the best varieties.
Hillier Trees has developed a number of cultivars that are now in widespread use across the UK. This includes the Hillier ‘Streetwise’ range, designed specifically for the growing number of tightly packed urban and suburban locations across the UK. This range has been developed by Hossein Arshadi, divisional director at Hillier Nurseries, over a period of many years to suit the modern urban environment and ensure our native trees can still thrive in these tricky urban spots.
Hillier Trees would welcome the development of more tree ranges designed specifically to meet the evolving needs of our local landscapes.
Acer campestre ‘Streetwise’
The field maple is a native tree that has been traditionally been planted among hedgerows and in open rural locations. Due to the unpredictable growth of its canopy, it is not a tree that naturally fits the high demands of inner-city urban planting. With the desire to create a uniform and consistent cultivar, Arshadi took cuttings from five specific field maples growing on Hillier Trees field nurseries that exhibited defined, upright branches. These five trees were propagated every 12 months and monitored for specific qualities, including outstanding autumn colour, pest and disease resistance, canopy shape and growth. After 18 years of propagation and thorough analysis, Hossein selected the best cultivar for performance against all these qualities, which is now available as the Acer campestre ‘Streetwise’ selection.
Hippophae salicifolia ‘Streetwise’
The creation of a ‘Streetwise’ version of sea buckthorn came off the back of a visit to Sir Harold Hillier Gardens in Hampshire. During the tour, Hossein discovered an unusual Hippophae multi-stem shrub with curious upright branches, that he believed could work brilliantly as a street tree. Hippophae salicifolia ‘Streetwise’ is an excellent choice for city applications. It tolerates all urban issues, including pollution and salt spreading. It has been used in difficult locations throughout London with great success.
Sorbus aucuparia ‘Streetwise’
This clonal selection of mountain ash, introduced by Hillier in 1998, was raised by Arshadi in the early 1980s at Hillier Tree Nurseries. This particular cultivar stood out as being an extremely robust grower, quick to establish at every stage of production. Sorbus aucuparia ‘Streetwise’ has a very neat, upright habit and its narrow, compact canopy makes this the best of the species for street and urban planting. Its vigour ensures that it establishes quickly on site, even in harsh conditions. The strongly ascending branch structure maintains the upright, tidy form throughout its maturity.
Tilia cordata ‘Streetwise’
Tilia cordata ‘Streetwise’ is a tree cultivated, introduced, and a personal favourite of Arshadi, the. This is part of the famous Hillier Streetwise selection, cultivated to ensure the continued planting of our native trees within the expanding urban environments. This seedling was first raised from mature lime trees in 1982. It was conspicuous thanks to its ‘well-behaved’ characteristics and uniformed canopy of ascending branches. Its healthy vigour very clearly set it apart from the other seedlings, and as the years progressed, these beneficial characteristics continued through to maturity.
Tilia cordata ‘Streetwise’ has become a significant rival to the industry known Tilia ‘Greenspire’, proving to be a better suited tree for urban applications. It has a noticeably faster growth rate than T. ‘Greenspire’, being consistently one nursery girth size larger at the same age. The leaves are also noticeably darker. This is due to increased quantity of chloroplasts that contain the chlorophyll, which highly absorb sunlight with low reflectance. This ensures the T. cordata ‘Streetwise’ has exceptional tolerance to periods of drought and heat. On the hottest days of the year, where other Tilia leaves are wilting, its leaves consistently remain vibrant and healthy. As the days progress and the summer becomes hotter, the new leaves of T. cordata ‘Streetwise’ open with much larger width and size to the first leaves produced. These larger leaves then quickly develop the same darker shades of green. By the autumn, the dark leaves have grown many times the size of the Greenspire. This larger size, thicker leaf with additional chloroplasts, along with its upright ascending canopy, make it the perfect tree for the difficult conditions of street urban planting.