More Green Spaces for Berlin

• The Stiftung Humboldt Forum im Berliner Schloss provides the basic structural framework for the tree islands.
• Interested donors can select their “preferred tree” from the profiles and write to the following email address: [email protected].
• Depending on the size, trunk circumference, and growth habit of the tree, the amounts that can be donated are €5,500, €6,500, €9,500, €11,000, and €14,000.
• Tree-related costs include: the cultivation and care of the tree in the nursery, transport, professional planting, substrate, underplanting/ground cover, and follow-up care.
• Planting begins in autumn 2026 with a joint watering ceremony involving all tree sponsors and project participants.
• All tree sponsors receive a certificate.
• Sponsors who wish to be acknowledged by name on-site can request this.

Every tree has its own character. The 18 species selected represent different regions of origin, growth habits, and special characteristics. Whether providing shade, withstanding drought, attracting bees, or boasting brilliant blossoms, each tree makes its own contribution to a lively, climate-adapted urban space. Discover your “preferred tree” from among the profiles below and accompany its planting at the Humboldt Forum by becoming a tree sponsor.

Celtis australis

Distribution: Native to Southern Europe, parts of Africa, and Turkey

Climate adaptation: Regarded as a “tree of the future”, winter-hardy and suited to changing climatic conditions

Growth habit: Broad, spreading crown, green foliage turning yellow in autumn, small, round purplish-black fruits

Tree island: Europe / Mediterranean region

Donation amount: All sponsorships already allocated

Celtis occidentalis

Distribution: Canada and the United States

Climate adaptation: Frost-hardy, heat- and drought-tolerant, urban climate-proof

Growth habit: Large, irregular crown, light yellow to yellow autumn foliage, fruits serve as food source for a variety of animals

Tree island: America

Donation amount: €6,500–9,500

Cercis siliquastrum

Distribution: Southern Europe, Mediterranean countries, and the Middle East

Climate adaptation: Urban climate-proof, drought-resistant, food source for butterflies and bees

Growth habit: Especially beautiful flowering tree, cauliflorous (producing flowers directly from the wood of the branches and the trunk), large, heart-shaped leaves, brown seed pods

Tree island: Europe / Mediterranean region

Donation amount: €5,500–9,500

Fraxinus ornus

Distribution: Mediterranean region, especially in Italy, along the Adriatic coast, and in Greece, extending into Turkey

Climate adaptation: Wind-proof, urban climate-proof, frost-hardy, and drought-tolerant

Growth habit: Beautiful spherical crown with glossy dark-green foliage turning yellow in autumn, striking in May owing to abundant white-yellow blossom

Tree island: Europe / Mediterranean region

Donation amount: €5,500

Gleditsia triacanthos inermis

Distribution: Widespread in North American mixed woodland along rivers

Climate adaptation: Tolerant of heat, drought, air pollution, gritting salt, and short wet spells

Growth habit: Turns golden yellow to greenish yellow in autumn, delicate foliage, thornless selection, egg-shaped to pyramidal, sparse crown, and bee-friendly

Tree island: America

Donation amount: €5,500 –14,000

Heptacodium miconioides

Distribution: Native to the Chinese provinces of Anhui, Hubei, and Zhejiang

Climate adaptation: Very winter-hardy, drought-tolerant

Growth habit: Early flowering in June, main flowering from August to October, fragrant creamy-white flowers with small white calyx, pinkish to deep purple fruit clusters

Tree island: Asia

Donation amount: €5,500–9,500

Pinus ponderosa

Distribution: Native to North American Rocky Mountains, spreading in a north–south direction from British Columbia to Mexico and eastward to Montana, Colorado, and Texas

Climate adaptation: Frost-hardy, drought-resistant, urban climate-proof, disease-tolerant

Growth habit: Stately evergreen tree, dark green needles, reddish-brown buds, egg-shaped cones

Tree island: America

Donation amount: €11,000–14,000

Pinus sylvestris

Distribution: Native to Europe, spreading from Spain to North Africa but also to the polar tree line and from western Europe via eastern Europe to East Asia

Climate adaptation: Robust, winter-hardy, and heat-tolerant pine species, low-maintenance and undemanding

Growth habit: Fast-growing conifer, crown varies from conical to umbrella-shaped and becomes hemispherical with age, bark turns reddish-brown as it ages

Tree island: Asia

Donation amount: €11,000–14,000

Prunus yedoensis

Distribution: All parts of Japan

Climate adaptation: Low-maintenance, winter-hardy, heat-loving, prefers sunny, warm locations

Growth habit: Upright, spreading small tree with exceptional abundance of white blossom, lightly fragrant flowers arranged in clusters that appear in March and April

Tree island: Asia

Donation amount: €5,500–14,000

Quercus acutissima

Distribution: Japan, Korea, and China, extending into the Himalayas and beyond to northern Thailand and northern Vietnam

Climate adaptation: Warmth-loving species that copes well with drought, air pollution, and gritting salt, making it a robust tree for climate change in Germany

Growth habit: Closed and broad, egg-shaped crown, lush foliage, semi-glossy and dark green leaves

Tree island: Asia

Donation amount: €9,500–11,000

Quercus pubescens

Distribution: Mainly in the Mediterranean region, France, Switzerland, and eastern to southern Austria but also native to a few parts of Germany

Climate adaptation: Better adapted to a warm, dry climate than pedunculate and sessile oak

Growth habit: Attractive bark, beautiful autumn colouring, deciduous or rarely semi-evergreen

Tree island: Europe / Mediterranean region

Donation amount: €6,500–9,500

Quercus texana ‘New Madrid’

Distribution: In the floodplain forests of the Mississippi River basin in the United States, extending from western Kentucky and Illinois to Louisiana, Alabama, and Texas

Climate adaptation: Loves sunny locations, insensitive to frost and wind

Growth habit: Attractive form and lush crown, highly valued for its ornamental foliage, deciduous, egg-shaped, and lobed leaves that transition from maroon to green, brilliant reddish-orange autumn colouring

Tree island: America

Donation amount: €5,500–11,000

Quercus x hispanica ‘Ambrozyana’

Distribution: Species hybrid from Quercus suber and Quercus cerris, originally from the Mediterranean region, extending from southern France and Italy to the Balkans

Climate adaptation: Warmth-loving, heat-tolerant, and drought-resistant

Growth habit: Round crown, glossy dark green leaves with slender tips, evergreen to semi-evergreen

Tree island: Europe / Mediterranean region

Donation amount: €11,000

Robinia margaretta ‘Pink Cascade’

Distribution: United States

Climate adaptation: Undemanding, urban climate-proof

Growth habit: Round crown, delicate pinnate leaves, brilliant purple-red blossom consisting of numerous small butterfly-like flowers in clusters up to 15 cm long, extremely prolific bloomer

Tree island: America

Donation amount: €5,500–14,000

Styphnolobium japonicum or Sophora japonica

Distribution: Japan, Korea, and China

Climate adaptation: Extremely tolerant of heat and drought, making it very well suited to an urban climate

Growth habit: Broad, oval, semi-open crown with green pinnate foliage, highly valued by butterflies and bees, thus regarded as bee-friendly

Tree island: Asia

Donation amount: €6,500–14,000

Zelkova serrata

Distribution: East Asia, spreading from Japan via South Korea to China and Taiwan, related to the European elm

Climate adaptation: Undemanding, drought-tolerant, regarded as a “climate-resilient” tree

Growth habit: Broad, spreading, loose crown, often multi-stemmed with short trunk, smooth bark becoming rough and peeling with age to reveal orange-red inner side and yellow-brown wood

Tree island: Asia

Donation amount: €5,500–14,000

Acer freemannii ‘Autumn Blaze’

Distribution: Widespread on the east coast of the United States from the Canadian border region to Florida

Climate adaptation: Frost-hardy, tolerant of brief periods of drought, insect-friendly blossom, low-maintenance, robust, highly adaptable to different locations, urban climate-proof

Growth habit: Oval, upright crown, smooth silvery-grey bark, brilliant red-orange autumnal colouring

Tree island: America

Donation amount: €5,500–11,000

Cedrus libani

Distribution: Southwestern Anatolia, Syria, and Lebanon

Climate adaptation: Highly adaptable to different locations and undemanding, extremely resilient to severe drought and very low temperatures

Growth habit: Evergreen conifer that can live up to 1,000 years, young trees have a pyramidal crown that becomes increasingly irregular with age

Tree island: Europe / Mediterranean region

Donation amount: €11,000–14,000