City Trees

It’s not easy for street trees in city locations. Especially in Berlin’s heavily built-up city center, conditions are usually worse than in natural settings and result in various kinds of damage having a strong negative impact on the trees’ health and vitality. That is why urban street trees in particular require exceptional maintenance.

For maintenance and safety reasons, street trees also require professional pruning in order to:

• Remove diseased, dying, dead, crossed, or rubbing branches,
• Keep trees from obscuring traffic signals,
• Maintain adequate clearance for vehicles (clearance pruning),
• Remove branches that could be hazardous,
• Cut crowns according to the tree species and its habitus,
• Cut clear adjacent facades.

In some cases even scaffold branches are cut back to reduce the weight of the crown, thus enhancing stability and avoiding the need to fell the tree. Large branches can also be radically cut back in trees where a cramped location has forced excessively linear growth at the expense of the trees’ natural growth pattern.

The relevant guidelines provide recommendations for tree-trimming. (see Berliner Standards zur Baumpflege. Teil 1 - Schnittmaßnahmen)

Maintenance measures also include dealing with damage to bark, wood and roots. Construction activities and traffic can be hard on urban street trees, and especially on the root area within the canopy drip line. Damage to the trunk and crown, however, can also seriously endanger trees. Detailed regulations like DIN 18 920 (in German) (Protection of Trees and Vegetation during Construction Work) and RAS-LP4; (in German) (Guidelines for the Construction of Roads, Chapter on Landscape Care, Section 4: Protecting Trees, Vegetation and Animals during Construction Measures) address construction and excavation carried out near trees.

The "city trees" working group of the Standing Conference of Parks Department Heads of the German Association of Cities (Ständige Konferenz der Gartenamtsleiter beim Deutschen Städtetag / GALK-DST) has drafted an informative Fact Sheet on Tree Protection at Construction Sites (Merkblatt zum Baumschutz auf Baustellen; in German), which it distributes free of charge.

Maintenance care also applies to the area surrounding the tree and is aimed at improving its physical, chemical and biological attributes. This includes:

• Soil structure,
• Aeration,
• Nutrient supply and availability,
• Water supply and disposability,
• Root growth.

Professional tree maintenance starts with planting, which, when done right, can help to protect trees from damage. Especially important are optimal root space, plant-friendly substrates and construction materials, site-appropriate tree selection, and protective facilities. Moreover a good maintenance right from the start (watering!) is extremely important.

The Berlin Standards for Planting and subsequent Care of Street Trees (Berliner Standards für die Pflanzung und die anschließende Pflege von Straßenbäumen; in German) by the Berlin Parks Department Conference (Berliner Gartenamtsleiterkonferenz - GALK Berlin) and the Recommendations for Tree Planting Part 1 und 2 (Empfehlungen für Baumpflanzungen, Teil 1 und Teil 2; in German) by the FLL give advice on all aspects of sustainable tree-planting, from the planning stage to the achievement of intended functions.

The Directive on the Construction and Maintenance of Urban Green Space (Rundschreiben über die Pflanzung sowie über die Pflege und Unterhaltung von Straßengrün; in German), drafted on the basis of §7 of the Berlin Roads Law (Berliner Straßengesetz; in German), contains similar recommendations for street trees in Berlin.

Berlin’s twelve borough parks departments (in German) are responsible for the trees along public roads and in parks.

The legal basis for the protection of trees in our city is the Berlin Tree-Protection Ordinance (Baumschutzverordnung; in German). More information can be found on the page Nature Conservation in Berlin (Naturschutz in Berlin / Baumschutz; in German).