Norway Maple ‘Globosum’ · Acer platanoides ‘Globosum’

Acer platanoides 'Globosum' is grafted onto a clear standard of 1.8 to 2.2 metres, above which a naturally spherical crown develops to 4 to 6 metres in diameter and a roughly matching height. Growth is very slow, and the habitus (Habitusform) holds its geometry without formative pruning. Yellow corymbs open in April before leaf-out, summer foliage is dense mid-green, and autumn colour is the gold-yellow inherited from the parent species.

Hardiness is not the limiting factor on any German site. The species Spitzahorn is native to Germany and reliably hardy below minus 30 degrees Celsius; the cultivar inherits this winter hardiness (Winterhärte) unchanged, so the grafted standard performs from the Oberrheingraben to the Mecklenburg lakes and into the voralpenland above 600 metres. The single material caveat is graft-union sun-scald on south-west exposures in the first three winters, addressed by trunk wrapping or whitewash.

Stadtbaumeignung for this cultivar is precisely defined by GaLaBau practice. The fixed crown geometry and 1.8 to 2.2 metre clear standard make it the conventional specification for parking-bay grids (Parkplatzbäume), narrow Wohnstraße alignments where a full-scale Stadtbaum would not fit, and the front-line position around plaza margins and tram-stop islands. It also reads as a formal solitary in courtyards built to FLL (Forschungsgesellschaft Landschaftsentwicklung Landschaftsbau) solitary specifications. De-icing salt tolerance and resistance to urban pollutants are inherited from the parent species and confirmed by long use across municipal Sortimente.

Maintenance load is the lowest of any commonly specified Stadtbaum. The spherical habit is self-sustaining, so the pruning regime is limited to dead-wood removal and occasional crown-edge trimming when neighbouring sight-lines or signage clearance require it. The species' shallow root system asks for a planting pit sized to the standard FLL profile and an open tree disc rather than turf to the trunk; on free-draining loam, on Rhine loess, and on glacial moraine across the central uplands the established tree is undemanding. Verticillium wilt remains the relevant pathogen on the parent species (Acer platanoides) and the cultivar is not exempt.