7 x edible shrubs for improving urban biodiversity

2. Cornelian cherry dogwood (Cornus Mas)

Cultivated for millennia for its wood and culinary uses, Cornelian cherry dogwood (Cornus mas) might just become your new best friend in the garden. It’s best known for its delicate yellow flowers and edible olive-shaped fruit, both of which are equally cherished by people and wildlife alike. In the Netherlands, it’s rare in the wild, limited to the southernmost parts of the country. 

When the garden starts to awake from the cold in early spring, the blossoming of Cornus Masis eagerly awaited – especially for the bumblebees as it’s one of their first food sources available after the long winter. Masses of fine bright yellow clusters of flowers covering this bushy shrub or small tree bring an instant cheer, especially on sunny days when the yellow blooms contrast strikingly with the deep blue sky. An added bonus is that it blooms for several weeks, meaning more time to enjoy this stunning shrub.

Cornus mas is also the host plant for moths including Eupoecilia ambiguellaand Antispila treitschkiella, -metallellaand –petryi. While moths aren’t as prominent as butterflies, they’re important as pollinators and a food source for birds and other wildlife. 

Like all dogwoods, Cornus masmakes a show of autumn colours when its glossy green leaves turn vibrant shades of burgundy tinged with purple. Look for bunches of ripening elongated ruby red fruit called cornels hiding between the colourful foliage. Birds adore them. When ripe, they’re soft and fall easily off the stalk. Their tartness lends itself well to jams and jellies but surprisingly they can also be brined and eaten like olives. As the pits were used as rosary beads, Cornus masis often found in monastery and cloister gardens. 

Cornus Mas stands the test of time, some growing to be over 100 years old! The Romans called it Cornus, meaning horn. As a tough hardwood, it’s been prized since ancient times particularly for spears, wheel spokes and tool handles but also shepherd’s staffs. 

It’s an easy friend in the garden as a hedge or standalone feature, thriving in sun and partial shade and most soil conditions – although it has a preference for chalky soils. It doesn’t mind drought nor wind and gets on well with most plants making it ideal as part of a diverse urban landscape.

7 x edible shrubs for improving urban biodiversity

In these blog posts, Maike van Stiphout (landscape architect and author of First Guide to Nature Inclusive Design) and Jeanne Tan (architecture writer and content editor) delve into the world of shrubs, sharing the beauty of this under appreciated group of plants which are ideal for urban nature, urban biodiversity and urban food forests. First up is Sloe famed for its ethereal white blossoms and its plum-like fruit. Supporting a wide variety of wildlife, the low maintenance Sloe shrub or hedge is a firm favourite for improving urban biodiversity all year round.

  1. Sloe or Blackthorn (Prunus spinosa)

Native to the Netherlands, Sloe is an ancient shrub that supports a wide variety of wildlife, making it one of our favourites to plant in urban landscapes to improve biodiversity all year round. It’s famed for its delicate white blossoms and edible dark purple fruit called sloes. Low maintenance Sloe shrubs suit rather wild landscapes and gardens and are excellent as hedges. It thrives in full sun but can tolerate some shade.

After long Dutch winters, a blossoming Sloe in March is a spectacle to celebrate – spring is on the way! They transform in early spring from a thick mass of thorny branches into ephemeral clouds of delicate white blossoms. Importantly, at this time when there’s little food available, Sloe blossoms provide precious nectar and pollen for bees, bumblebees and butterflies. After the blossoms have been pollinated, the fruit appears. 

Later in the season Sloe becomes a favourite foodplant for the caterpillars of moths and butterflies, in particular the black hairstreak (Satyrium pruni) which lay their eggs almost exclusively here. This butterflie is extremely rare in The Netherlands.

Sloe provides an ideal nesting habitat for birds – especially with caterpillars, an important food source, within easy reach. Although Sloe is deciduous, its dense, thorny branches offer shelter to birds and other wildlife against urban predators all year round.

Come autumn, the small oval leaves turn orange and the clusters of fruit ripen into a rich dark purple – a beautiful sight. Resembling mini plums, sloes are the predecessor of our cultivated plums. Try to spot birds such as thrushes feasting on them. If you’re going to harvest some, don’t be tempted to eat them straight away – they’re astringent and tart. Traditionally sloes are prized for making jam and wine and infusing liqueur such as Slivovitsj.

Trees, Urban Ecosystem Services and the ‘Internet of Nature’

In the 2020 virtual tour on her city’s Arboreal Wonders Amsterdam based researcher Nadina Galle lines up a variety of beneficial ecosystem services of city trees as key ingredients for a biodiverse city.

Already when planted the service expected by the elm trees in Amsterdam was to strengthen the canal quay sides with their vertical roots. Today there are 400.000 trees along streets and canals, and more than one million trees in the entire city offering many services. Software like iTree helps quantify these value of trees. Next to cooling and a pleasant soundscape these values include the increase of property value, and safety by lowering traffic speed and decreasing crime. In addition, trees help to buffer storm waters, store carbon dioxide and improve health by lowering stress and blood pressure, says Galle.

The Amsterdam Urban Nature Map (also available for Breda) shows all the green and blue public spaces, and how to better use urban nature. More information on trees and their benefits can be seen on the Interactive Amsterdam Tree Map, and MIT’s Treepedia. Or use an identification app such as PlantSnap, iNaturalist or PictureThis. Speaking with Nadine get one and have ‘a botanist in your pocket!’

© Still by Nadina Galle, video by Christiaan Kanis

Building with Nature perspectives

A new publication about Building with nature is published by Rius (Research in Urbanism Series), TU Delft. This publication offers an overview of the latest cross-disciplinary developments in the field of Building with Nature for the protection of coastal regions.

Drawing from the experience of DS landscape architects, four actualized projects and two student master theses of the Academy of Architecture illustrate the challenges, opportunities and benefits that building with nature presents. These cases highlight four important lessons for designing with nature in rural and urban landscapes

Publication: https://www.rius.ac/index.php/rius/issue/view/10/10

The Nature of Cities Festival 22-26 February 2021

“The 2021 TNOC Festival pushes boundaries to radically imagine our cities for the future. Join a diverse international community of urban thinkers to re-imagine our cities today, to build the cities of tomorrow.

This virtual festival spans 5 days with programming across all regional time zones and provided in multiple languages. TNOC Festival “offers the ability to truly connect local place and ideas on a global scale for a much broader perspective and participation than any one physical meeting in any one city could ever have achieved.

Look at the program and register (100 USD for Global North).

Green ‘city skin’ delivers many ecosystem services

Protecting the ‘skin’ of the city with all forms of greenery delivers a wide array of ecosystem services, as Nicole Pfoser shows in her research already in 2012. While the unprotected skin leads to noisy, hot and flooded cities, the ‘city skin’ composed of roofs, facades and public space surfaces delivers sound absorption, water buffering, reduction of urban heat islands – and an increase in urban biodiversity, when protected with urban flora.

Download the full (and free) report of Mrs. Pfoser at the German Fraunhofer Insitute.

Viennese public transport company contributes to biodiversity

There is also positive news from Vienna these days: Because securing biodiversity on public green spaces is important – they are not only attractive areas to be used by people and animals and help cooling down the city in the summer – the University of Natural Resources and Life Sciences Vienna (Boku) was asked by the metropolitan public transport company (Wiener Linien) how to preserve and maintain these spaces appropriately. A large scale investigation into insect and plant species on 20+ green spaces along the public transport network has shown surprising results.

In the only 3.7 hectares studied 378 species of plants and a third of all 460 bee species in Vienna could be found. This is remarkable, given the more than 200 km2 of green space in the entire metropole, and stresses the importance of transport infrastructure for green-blue urban networks in the city, and Quality of Life.

Read more on the still ongoing research of Bärbel Pachinger and Sophie Kratschmer at Wiener Linien or Der Standard. Final results will be published in 2021, see the university website for details. Image is (c) Boku.

Porosity for closed buildings and a park instead of parked cars: the new BUas campus in Breda contributes to quality of life in the city

The city of Breda has formulated the ambition to become the first ‘City in the Park’ and has been working consequently on improving biodiversity and nature-inclusive building. Recently the Breda Architecture Award 2020 (BLASt Prize) was awarded to the new Breda University of Applied Sciences Campus, a design by Inbo and Culd. In the heart of the project a formerly car-lined road was transferred into a new park. The courtyard of the adjacent cloister was opened up towards the new green campus. Even when the university buildings might be closed due to covid-19, the new campus space is open to the public and contributes to quality of life in the city.

Stichting BLASt
Inbo architects
Culd landscape architects

The end of the stone gardens in Baden-Würthemberg

The stone garden increases the climat problems such as heatstress and stormwater floods in the neighbourhoods. Since a few days a stone garden is forbidden in Baden-Würthemberg. Their garden-legislation (1995) prescribed that paving is only allowed where it is really needed. The recent garden trend to replace plants by small pebbles was not foreseen and not stopped. The film explains to the inhabitants why the new law is made and how to change the garden.

film in: https://www.swr.de/swraktuell/baden-wuerttemberg/schottergaerten-ministerien-uneins-100.html