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Blog Article

Go green: How cities can overcome the challenge of greening urban spaces with Capillary Hydroponics

Editorial Team
Go green: How cities can overcome the challenge of greening urban spaces with Capillary Hydroponics
August 25, 2023

Green infrastructure is pivotal to overcome many challenges cities worldwide face today

All throughout the world major cities find themselves caught in a paradoxical situation. On one hand, these cities are facing a pressing need for green spaces such as parks and lawns to counteract the detrimental effects of noise, dust pollution, and climate change. On the other hand, the increasingly hot and dry summers in Europe, as well as severe drought conditions in California, Arizona, and the mid-west of the US, are compelling authorities to enforce water restrictions, hindering the growth and upkeep of these essential urban green spaces.

Similarly, both the US and Europe have recognized the importance of 'green infrastructure' as a means to mitigate the impact of climate change, leading to significant investments in sustainable green infrastructure. Cities like New York, Chicago and Atlanta in the US, and London, Paris and Barcelona in Europe have implemented comprehensive green infrastructure plans that prioritize parks, green roofs, and permeable surfaces to improve air and water quality, reduce urban heat island effects, and enhance biodiversity. These initiatives highlight the growing awareness and commitment to incorporating nature-based solutions into urban environments for a more sustainable future.

However, when faced with the dilemma of water scarcity and the need to conserve resources, authorities grapple with the challenge of finding a balance between expanding green infrastructure in urban areas and the practical limitations imposed by concerns about irrigation and maintenance.

To address the challenges posed by water scarcity and the need for resource conservation, an alternative approach that is often overlooked involves keeping public spaces and private lawns green with reduced water consumption and minimizing the use of harmful chemicals through the use of hydroponics.

In this article, we will delve into the historical significance of green spaces and their evolving role in shaping urban environments. We will also examine the challenges posed by climate change and explore the potential of Capillary Hydroponics, an innovative solution for growing strong, durable, and low-maintenance grass in public spaces.

Hardscape plaza with building surrounding it

A brief history of human-made green spaces

Historically, human-made green spaces have played a significant role in Europe since the Middle Ages, serving cultural and aesthetic functions. These lush expanses were developed during periods of political stability, and were symbols of power and prosperity. Significantly, even in the 21st century, access to expansive green spaces remain disproportionately available to the privileged. For many urban dwellers, green spaces found on road verges or public spaces adjacent to buildings often serve as the sole means through which they experience nature. These strips of mostly grass are planted primarily for visual enhancement, but they bring a multitude of benefits that contribute to the overall well-being of urban environments and their inhabitants.

The World Health Organization (WHO) advises that urban residents should have access to a minimum of 0.5-1 hectare of public green space within a 300-meter radius of their homes. This recommendation aims to promote the well-being and health of urban populations.

Similarly, the United Nations Children's Fund (UNICEF) emphasizes the importance of safe public access to green spaces and the need to accommodate various groups simultaneously. They specifically highlight the benefits of greening school grounds, as it encourages more active play among children. Examples from Flanders and Paris demonstrate that greening school grounds not only benefits children but also the wider community, particularly during heatwaves, when the school grounds are open to the public.

This is why cities need to prioritize the availability of green spaces and promote the greening of urban spaces. By ensuring the creation of, and access to, grassy areas, cities can bridge the gap between privileged and underprivileged communities, offering equal opportunities for everyone to connect with nature and improving their overall well-being and quality of life.

Benefits of grass in urban areas

Let's explore the many advantages that growing grass offers to cities, demonstrating how even this seemingly simple and commonplace element can effectively transform urban spaces with its numerous benefits.

  • Carbon sequestration: Grass absorbs carbon dioxide from the atmosphere and releases oxygen. In doing so, it helps counteract the harmful effects of carbon emissions and helps mitigate air pollution and improve overall air quality in urban areas.
  • Natural filtration: Grass acts as a natural filter for water runoff, playing a crucial role in improving water quality. When it rains, water percolates through the soil and grass roots, acting as a natural filtration system. Grass helps trap and break down pollutants, such as heavy metals and sediment, preventing them from entering water bodies and contaminating water sources. This filtration process contributes to the preservation of water quality and the overall health of ecosystems.
  • Mitigating the urban heat island effect: Urban areas often experience higher temperatures compared to their surrounding rural areas due to the heat island effect because of the extensive use of concrete, asphalt, and other heat-absorbing materials in these spaces. Grass plays a vital role in mitigating this urban heat island effect by cooling the surrounding environment. In fact, a study in the UK found that planting grass reduced maximum surface temperatures by up to 24 °C. This is because grass absorbs less heat than hard surfaces and, through a process called evapotranspiration, releases moisture into the air, creating a cooling effect. This natural cooling property of grass helps reduce temperatures, create a more comfortable urban climate, and mitigate heat-related challenges faced by city dwellers. There’s more evidence of this. Heat mapping and thermal infrared imagery studies in a 285 sqkm region of Adelaide, South Australia, revealed the temperature differences in urban areas. Cooler sites were identified as irrigated turf, golf courses, water bodies and dense woody vegetation while the hottest areas consisted mainly of buildings, dry agricultural fields, dry or dead grass and vegetation, exposed soil, and unshaded hard surfaces. Similar research conducted in Perth, Western Australia, found that areas with grey pavers were the hottest, while areas with ground-cover plants were the coolest during the day. In the evenings, grey pavers remained the hottest, while turf grass, decking and soil were the coolest. These findings highlight the varying temperatures associated with different types of urban landscape elements.
  • Reducing Flooding: Grass, known for its natural water absorption capabilities, acts as a sponge, effectively soaking up rainwater and slowing down the flow of stormwater runoff. This characteristic becomes particularly significant during sudden heavy downpours or extended periods of excessive rain. By absorbing rainwater, grass helps mitigate the strain on stormwater drainage systems, which often struggle to handle sudden surges of water. As the grass retains the water, it gradually releases it into the ground, allowing for groundwater reserves to recharge and reducing the risk of surface flooding. This not only protects urban infrastructure and properties but also safeguards delicate ecosystems from the damaging effects of floods. This is one of the reasons why grass is also an indispensable component of effective stormwater management strategies.
  • Noise reduction: Grass absorbs and disperses sound waves, acting as a natural sound barrier and reducing noise pollution. By creating a buffer between buildings and busy streets, vegetation including grass helps reduce the disruptive effects of noise.
  • Habitat for wildlife: Urban areas often lack natural habitats for wildlife, but grass can provide a valuable refuge for various species. Grass supports a diverse range of insects, birds, and small mammals, offering food sources, nesting sites, and shelter.
  • Well-being and recreation: The presence of grass in urban spaces has been shown to have a positive impact on the well-being of city dwellers. Research suggests that exposure to green spaces, including grassy areas, can reduce stress levels, improve mental health, and enhance overall quality of life. Grass also provides opportunities for recreation, offering spaces for outdoor activities, picnics, sports, and leisurely walks. These recreational opportunities foster community engagement and social interaction, contributing to a sense of well-being and connection among residents.
different types of green ifnrastructure sitting on top of building, aerial view

But why don’t cities grow more grass?

Despite the numerous advantages of grass in urban green areas, there are several reasons why cities around the world do not prioritize the growth of grass in public spaces.

Firstly, the maintenance and care required for grass can be challenging and costly. Grass needs regular watering, mowing, fertilization, and pest control, which can be resource-intensive and time-consuming. In comparison, concrete or asphalt surfaces are perceived as low-maintenance options that require minimal upkeep.

Additionally, the rapid pace of urbanization and limited space in densely populated cities pose challenges for allocating areas for grass growth within the framework of green infrastructure development. The demand for housing, infrastructure development, and commercial spaces often takes precedence over the creation of green spaces.

Furthermore, soil-grown grass is not durable and there are valid concerns that high footfall and usage in heavily trafficked areas could lead to wear and tear, often creating dry spots that contribute further to dust pollution. Balancing the desire for green spaces as part of green infrastructure with the practical considerations of urban planning can present a complex challenge for city authorities.

However, with the emergence of innovative solutions like Capillary Hydroponics, there is an opportunity to reimagine and reintroduce grass in a large way in urban landscapes, enhancing the liveability and sustainability of cities while promoting green infrastructure development.

beautiful urban lake with green spce close to a texas neighbourhood

Grow strong and resilient grass with Capillary Hydroponics

Capillary Hydroponics is a radical new irrigation system that uses an oxygenated and fertilized moving underground water table to grow turf grass. In doing so, it decreases water loss and consumption by up to 85% while ensuring that the turf grass grown is stronger and more durable with significantly less maintenance and environmental impact.

At the core of Capillary Hydroponics is Capillary Material, formerly known as Capillary Concrete. This patented and engineered polymer-based pervious concrete is the only building material that can rapidly drain water while also moving water up. Invented in 2009, it is also behind one of CapillaryFlow’s most successful solutions, Capillary Bunkers, which has transformed the way the golf industry constructs and maintains bunkers.

The Capillary Hydroponics system comprises several layers: an impermeable liner that sits on the soil, drainage pipes, drainage gravel, a layer of Capillary Material, washed sand and finally grass. The area under the surface is split into two equally large parts. A control basin filled with water is placed on the outside and has pipes that feed into the middle of each cavity. It automatically oxygenates and pumps fertilized water back and forth between the two sections several times a day, watering the roots as it goes. When the water moves and enters or exits the pores of the root-zone material, the gas exchange increases by up to 6,000%.

The level of the water table is completely controllable and the water moves between each cavity at a fully adjustable rate too. This system minimizes the amount of water required and promotes strong root growth.

Capillary Material ensures a perfectly flat and level base beneath the rootzone, which is crucial for the functioning of a hydroponic system.

The benefits of using the Capillary Hydroponics system to grow grass in urban areas, sport fields and equestrian venues are many:

  • Water conservation: With water savings of up to 85%, Capillary Hydroponics addresses one of the most pressing concerns in urban environments – water scarcity – while still effectively irrigating grass.
  • Water storage: The water storage capacity of the system depends on the depth of the gravel layer. For instance, if using 20 cm of gravel, a football field using Capillary Hydroponics can store 459,000 liters of water.
  • Grow stronger and resilient turfgrass: Promotes the growth of robust and durable turfgrass, ensuring consistent performance in various scenarios.
  • Lower maintenance costs: Reduces the need for extensive maintenance, saving time and resources typically associated with traditional grass care.
  • Environmental sustainability: Capillary Hydroponics has significant advantages in terms of environmental sustainability when compared to soil-grown grass that is irrigated via non-hydroponic systems. For one, it generates lower net carbon emissions, contributing positively to the environment. Moreover, the technology acts as a barrier, preventing the release of microplastics, pesticides, and fertilizers into the environment, thereby curbing their detrimental effects. Additionally, it aids in mitigating flooding impacts by efficiently absorbing water during heavy downpours or prolonged periods of excessive rain. This not only underscores the ecological benefits of Capillary Hydroponics but also reinforces its role in comprehensive stormwater management strategies.
  • Improved playability: By optimizing the conditions for grass growth, Capillary Hydroponics enhances the playability of golf courses, sports arenas, and other recreational spaces.
  • Transformation of urban spaces: The technology allows the conversion of hardscape surfaces into lush grass, bringing nature back to the heart of our cities. Additionally, the system’s structure makes the grass very resistant to compaction when people walk or drive on it. 


In conclusion, it is clear that every city in the world needs more green spaces because they are essential to counteract the detrimental effects of pollution and climate change. The numerous benefits of growing grass in urban areas, such as enhancing air quality, natural filtration, mitigating the urban heat island effect, noise reduction, providing habitats for wildlife, and promoting well-being and recreation, underscore the importance of prioritizing the availability and growth of grass in cities.

Having said that, city authorities – though keen on investing in green infrastructure – also need to take into consideration practical problems like the scarcity of water. 

This is where CapillaryFlow’s innovation shines. Capillary Hydroponics presents cities and municipalities with the opportunity to reintroduce grass into urban landscapes, effectively transforming concrete and asphalt surfaces into vibrant green spaces that enhance the liveability and sustainability of urban areas without the challenges of soil-grown grass. This is because unlike traditional soil-grown grass, Capillary Hydroponics requires significantly less maintenance, 85% less water, and boasts remarkable resistance to high footfall. This is achieved through the hydroponic system, which not only uses significantly less water but also facilitates a gas exchange of up to 6,000% in the rootzone, ensuring healthier and more resilient root growth.


Want to know more about our products?

Would you like to know more about how Capillary Hydroponics can contribute to your Green Infrastructure initiatives? Contact us!


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