MODERN URBAN TREES CLIMATE RESISTANT & FUTURE-PROOF WWW.CLASEN-CO.COM CONTENTS „Trees in cities produce oxygen, trap dust, provide shade, absorb noise and cool the air. They crea- te spaces, are visually appealing and soothe the soul. Ironically, it is the place where people need trees the most that they find it the toughest.“ Dirk Clasen & Mark Schneekloth Managing Directors 04 ..... Acer truncatum ‚Norwegian Sunset‘® 05 ..... Alnus spaethii 06 ..... Carpinus betulus ‚Frans Fontaine‘ 07 ..... Fraxinus ‚Summit Ash‘ 08 ..... Malus ‚Stenström‘ 09 ..... ALLEEGRO®: Soil-based cultivation of modern urban trees 10 ..... Ostrya carpinifolia 11 ..... Quercus cerris 12 ..... Sorbus ‚Dodong‘ 13 ..... Sorbus incana 14 ..... Tilia platyphyllos ‚Örebro‘ 15 ..... Tilia tomentosa ‚Fastigiata‘ 16 ..... Ulmus ‚Fiorente‘ RESISTA® 17 ..... Ulmus ‚Rebona‘ RESISTA® 18 ..... Ulmus ‚New Horizon‘ RESISTA® (Cover) 19 ..... Zelkova serrata ‚Green Vase‘ 02 MODERN URBAN TREES WHAT MAKES THEM IMPORTANT Dear customers, The pages that follow present the range of trees that we firmly believe will reliably live up to the requirements of urban locations. The selected trees have already successfully proven themsel- ves in our own observations and according to our customers. The ‘modern urban trees’ counter extreme levels of heat and frost, dryness and waterlogging with outstanding vitality and little maintenance. In addition to the location-induced conditions, we have also considered the whole broad range of tasks of a functioning urban green space. This range will therefore always offer you the right trees for your urban projects. Without exception, all of our ‘modern urban trees’ are ALLEEGRO® trees, i.e. container trees that have been cultivated by Clasen & Co using the technology we have developed. The nursing, prun- ing and optimum nutrient supply methods that we have created, in conjunction with the unique ALLEEGRO® soil, aim to optimally develop the trees’ vitality and offer them advantages through reliable establishment behaviour. This is a quality feature that you can rely on. 03 ACER TRUNCAtum ‚NORWEGIan sunset‘® Scarlet maple ‚NORWEGIAN Sunset’® SPE CIFICATIONS Home/origin Cultivar (Acer truncatum x Acer plata- Soil/location The variety tolerates all types of soil noides ‚Keithsform‘) and also withstands damp but not ext- remely wet locations. It flourishes best Growth The crown is an elongated oval shape, in full sun to part shade. relatively fast growing and up to 12 m tall and about 7 to 8 m wide when Suitability The tree grows quickly but remains mature. relatively small, with leaves that turn spectacular colours in autumn. It is a Foliage The deciduous leaves are opposite, versatile and visually attractive tree for usually three-lobed, dark green and urban environments. glossy. They are smaller and more lea- thery than those of the Norway maple. Special notes An extremely healthy, vigorous and In autumn, the leaves turn impressive frost-hardy new variety. No cracks have shades of yellow, orange and bright red. yet appeared in trunks. Flowers/fruit The flowers are relatively inconspi- Delivery format As a tall-trunk tree in a container with cuous and appear before and while the trunk diameters of: leaves are growing. The amount of fruit 14 -16 -18 -20 -25 cm is negligibly small. 04 ‹‹ CONTENTS ALNUS SPAETHII SPAETH ALDER SPE CIFICATIONS Home/origin Cultivar (Alnus japonica x subcordata) Suitability Suitable as a street tree and for group or specimen planting in parks Growth Medium-sized, fast-growing tree with a and landscaped areas. loose, pyramidal crown. Some branches spread out horizontally. The bark is grey Special notes The autumn foliage is long lasting. to olive-brown. Delivery format As a tall-trunk tree in a container with Foliage The tree grows large, deciduous, lea- trunk diameters of: thery leaves. 16 -18 -20 cm Flowers/fruit The Alnus spaethii forms brownish- yellow catkins in January/February and produces large, ovoid, cone-like fruit in autumn. Soil/location The tree is undemanding and suitable for all soil types. It is lime tolerant and flourishes best in full sun to part shade. ‹‹ CONTENTS 05 Carpinuns betulus ‚FRANS Fontaine‘ PYRAMIDAL HORNBEAM SPE CIFICATIONS Home/origin Cultivar Special notes The Carpinus betulus ‘Frans Fontaine’ is an extremely wind resistant tree. Growth Narrow, ovoid column shape when young, not overly dense; no pruning Delivery format As a tall-trunk tree in a container with needed with age; 8 to 10 m high and 2 trunk diameters of: to 3 m wide. 14 -16 -18 -20 cm Foliage Medium-sized, light green ovate leaves, which turn golden yellow in autumn. Flowers/fruit The male tree bears green catkins in April/May. No fruit are produced. Soil/location This variety prefers loamy, humus soil in full sun to part shade. Suitability Its narrow crown makes this variety ideal for inner-city locations with little space, but also for parks and public spaces. 06 ‹‹ CONTENTS fraxinus ‚SUMMIT Ash‘ GREEN ASH S PECIFICATIONS Home/origin Cultivar Suitability Street and park tree for specimen plan- ting. Growth The wide, ovate crown grows to heights of 15 to 18 m. Special notes The variety is frost hardy, wind resis- tant and not affected by Dutch elm Foliage The leaves are deciduous, opposite, disease. irregularly pinnate and about 35 cm long. They are generally formed from Delivery format As a tall-trunk tree in a container with 7 to 9 ovate to lanceolate, dark green trunk diameters of: individual leaves with a lighter undersi- 14 -16 -18 -20 cm de. The leaves turn a spectacular shade of yellow in autumn. Flowers/fruit The flowers appear before the leaves and are inconspicuous. No fruit is ge- nerally formed. Soil/location The Fraxinus ‚Summit Ash’ is generally undemanding and prefers damp, slight- ly acidic soils in full sun to part shade. ‹‹ CONTENTS 07 malus ‚Stenström‘ RED-LEAVED CRABAPPLE S PECIFICATIONS Home/origin Cultivar, created in Scandinavia Suitability Very healthy and, above all, reliable red-leaved crabapple. Growth Extremely regular, pyramidal crown with a single leader; reaches heights of Special notes The Malus ‚Stenström’ is frost hardy and 5 to 6 m. resistant to urban climates. It is a honey plant and source of food for birds. Foliage Deciduous, alternate, very healthy red- wine-coloured leaves that do not turn Delivery format As a tall-trunk tree in a container with green even in late summer. trunk diameters of: 14 -16 -18 cm Flowers/fruit The bright pink flowers appear at the same time as the leaves in May. The relatively small fruit are a rich shade of dark red. Soil/location Like all crabapples, this variety is high- ly adaptable. It prefers nutrient-rich, fresh to damp soil in full sun. 08 ‹‹ CONTENTS ALLEEGRO® SOIL-BASED CULTIVATION FOR MODERN URBAN TREES T OTALLY HASSLE-FREE! „Once planted, the trees simply continu- ed to grow! There was no stressing about them as they established themselves.“ This is how a landscape architect and customer described his first experiences with our ALLEEGRO® trees. He also immediately provided the following explanation: „All the roots pe- netrate the tree pit without resistance as the structure of the ALLEEGRO® soil is very similar to the tree pit soil used in accordance with FLL Regulations“. The trees in Stuttgart were planted at the height of summer and the newly planted trees grew solidly in the high temperatures. WHAT IS ALLEEGRO® ? E ASY ESTABLISHMENT ALLEEGRO® is a modern concept ALLEEGRO® trees are not dug up and developed by Clasen & Co for culti- come with all of their healthy fine roots. vating container trees. The ALLEEGRO® approach is tailored to the needs and The soil used for the ALLEEGRO® trees performance profile of the individual has outstanding water retention and plants and covers all aspects from the drainage properties. The structure and selection of seedlings to the intervals density of the ALLEEGRO® soil vastly re- for potting and corrective pruning, the duce granular breakage. The roots can targeted supply of nutrients and, of penetrate the surrounding soil quickly course, the use of our ALLEEGRO® soil. and easily. This technology enables us to produce The trees are easy to handle on the attractive, premium trees of consistent- construction site as the volume weight ly high quality. of the ALLEEGRO® soil is 40% less than that of balls of earth. Less mechani- When planting greenery in the most cal work is required and the trunk is difficult locations, especially urban ones, protected. ALLEEGRO® trees not only offer the ad- vantages of vitality and robustness, but If you would like to find out more about also decisive benefits with regard to the ALLEEGRO®, we will gladly provide you trees’ handling on construction sites and with information. Further details can their establishment at the final location. also be found on our website. Fast, successful growth furthermore minimises maintenance and costs. ‹‹ CONTENTS 09 OSTRYA CARPINIFOLIA EUROPEAN HOP HORNBEAM S PECIFICATIONS Home/origin Southern Europe, mainly in the eastern Soil/location The Ostrya carpinifolia is generally very Mediterranean. adaptable and flourishes even in very dry and poor soil. It should be planted Growth The Ostrya carpinifolia is a medium- in a sunny, warm and protected location. sized tree. Its crown is conical when young and becomes uniformly circular Suitability This tree is ideal for inner-city areas. with age. The tree reaches heights of 10 to 15 m and is 8 to 12 m wide. Special notes The tree is extraordinarily tolerant of urban climates! It is frost hardy and Foliage The deciduous, alternate leaves are can withstand high temperatures and very similar to those on the hornbeam. dry air extremely well. Flowers/fruit The flowers appear with the leaves and Delivery format As a tall-trunk tree in a container with look very much like hops – hence the trunk diameters of: tree’s English name.