How many trees does it take to change the way an ordinary courtyard between apartment blocks breathes? In our case, the answer is 300 – and 27 pairs of hands that refused to give up even when the ground pushed back.
On 17 April we met on Warsaw’s Bielany with a group of employees from Novo Nordisk to plant trees together in the courtyards between residential blocks. This is a place residents pass every single day – on their way to work, to school, or out walking the dog – and one that, from now on, will look a little greener with every passing season.
A courtyard waiting for its next chapter
The site we worked on was not a random patch of land. The Bielany district office had already modernised it earlier, renewing the surfaces and rest areas between the buildings. What was still missing was what truly changes the character of a space like this – trees. Our planting was therefore a natural next step, building on work the district had already completed.
Courtyards between apartment blocks rarely come to mind when we think of nature, yet it is exactly in places like this that greenery matters most. Residents do not need to travel to a park or a forest to encounter nature – they simply need to step outside their front door. Concrete squares, pavements and building facades can heat up several degrees more than green areas in the same neighbourhood during summer, creating what is known as an urban heat island. Trees act as a kind of natural air conditioning for these spaces – their canopies provide shade, and water evaporating from their leaves cools the surrounding air. Thanks to 300 new trees, this corner of Bielany will become noticeably more bearable on hot days, year after year.
Greenery between blocks also affects something we talk about less often – how residents actually use shared space. Where trees grow, people are more likely to step outside, stay longer in the courtyard, and children have somewhere to shelter from the sun while playing. A green courtyard is simply a courtyard people use more, and more willingly.
Rowan, linden and maple – why these species
In Bielany we planted three species: common rowan, small-leaved linden and Norway maple. All three are native species well adapted to the Polish climate and to the difficult soil conditions found in cities, giving them a real chance of survival even among dense apartment-block development, where soil is often compacted and poor in nutrients.
Small-leaved linden is one of the favourite trees of bees and other pollinating insects. Its flowers release an intense scent and abundant nectar, which matters a great deal in cities, where pollinators frequently struggle to find food. Common rowan, in turn, will produce red berries by autumn, becoming a food source for birds – blackbirds, starlings, waxwings – that stay in the city through winter, when natural food is much scarcer. Norway maple will provide dense shade during the hot months and will help filter air pollution, including PM10 and PM2.5 particulates, which settle on leaf surfaces and are washed by rain into the soil rather than into residents’ lungs.
A mature deciduous tree can absorb dozens of kilograms of carbon dioxide a year and produce enough oxygen for several people. Three hundred new trees, once fully grown, will have a real, measurable impact on air quality in this part of Warsaw – while also creating habitats for insects, birds and small mammals, which are in shortest supply in densely built-up districts.
Hard ground, soft hearts
Planting was not the easiest task we have taken on. The terrain proved demanding – the soil was hard and dry, which made digging holes for the saplings considerably harder. In many spots, volunteers had to return to the same hole several times, breaking up compacted earth before reaching the right depth.
Despite this, the group from Novo Nordisk approached the task with full commitment. Nobody gave up, and breaks were taken only to catch their breath, drink some water, and return to work with even more energy. Participants repeatedly said this was exactly why they had come – to work hard and get properly tired, knowing the result of their effort would remain in this place for decades, long after the difficulties of one afternoon were forgotten.
For many of them, it was also a chance to step away from their desks and do something tangible for their neighbourhood – something they could later point to and tell their children or neighbours: I planted that tree with my own hands.
27 pairs of hands, one goal
The group of 27 volunteers from Novo Nordisk was remarkably well organised from the very start of the day. Tasks were divided efficiently – some dug holes, others prepared the saplings, and others handled watering and staking the young trees – so the work progressed without unnecessary delays, even while dealing with stubborn ground.
The atmosphere throughout the day was excellent. People cheered each other on with every new sapling, shared tips on how best to break through the hard crust of soil, and celebrated together each time another tree went into the ground. What pleased them most was the chance to plant trees right in the middle of the city and genuinely support the local ecosystem, rather than simply discussing sustainability during company training sessions or presentations.
That enthusiasm showed clearly in the conversation and in the pace of work alike – the group finished planting all 300 trees despite the difficult ground conditions, an achievement in itself.
Trees as part of the city’s infrastructure
It is worth looking at this action through a wider lens than a single afternoon of planting. Urban trees are increasingly treated as a genuine piece of city infrastructure, alongside pavements, streetlights and benches – except their value grows every year rather than depreciating. The root systems of 300 new trees will, over time, absorb rainwater, reducing the risk of local flooding after the heavy storms that have become more frequent in Warsaw. The leaves and branches will also naturally dampen traffic noise, which matters for residents of an estate surrounded by busy roads.
Greenery’s effect on wellbeing is not negligible either. Research in environmental psychology has repeatedly shown that even brief visual contact with trees, or a view of greenery from a window, lowers stress levels and improves concentration. For residents living around the courtyard on Cmentarna Street – and there are many similar spots across Bielany – this means an ordinary walk to the shops or a school run will become a slightly more pleasant experience.
What Bielany gains
The result of this joint effort is 300 new trees in the ground and the start of a long process that will keep developing over the coming years. The trees planted on 17 April will grow alongside the residents of this part of Bielany – providing shade on hot days, shelter for birds and insects, and a little more greenery in a space that lacked it, even after the district’s earlier modernisation work.
Over time, as the rowans bear their first berries and the lindens bloom and draw in bees, residents will see that this courtyard has changed both in appearance and in function. It has become a place that actively supports local nature, rather than simply sitting next to it from a distance.
We thank the employees of Novo Nordisk for their commitment and determination, especially in the face of hard, unyielding ground that demanded more effort than usual. We also thank the Bielany district office for preparing the site for planting in advance.
Days like this one rarely make headlines, yet they quietly add up to something larger. Every courtyard replanted, every hard patch of soil turned into space for roots to grow, brings this part of Warsaw a step closer to being a genuinely green city rather than one with scattered green spots. We hope this is not our last joint action with Novo Nordisk, and that more courtyards across Warsaw will soon undergo a similarly green transformation.
