Urban green spaces are shedding their aesthetic value and becoming more socially significant as they return to the ancient rural traditions that shaped human history. Roof gardening is therefore an opportunity to grow agricultural crops rather than decorative plants.
What is Roof Gardening?
A roof garden is a garden built on top of a building. Generally speaking, roof gardens refer to any vegetation established on the roof of a building. Along with providing decorative benefits, roof gardening also provides architectural enhancement, temperature control, recreational opportunities, habitat for wildlife, and food.
The term “rooftop farming” refers to farming food on roofs. This includes:
- Container gardens,
- Air-dynamics,
- Aeroponics,
- Hydroponics,
- Green roofs, etc.
In addition to the roof space, it is also possible to build additional platforms known as “aero-bridges” between high-rise buildings.
Effects On The Environment
Roof gardens are most likely to be found in urban environments. Besides reducing heat absorption, plants also reduce energy consumption for cooling. During transpiration, plant surfaces rarely exceed 4–5 degrees Celsius (7–9 degrees Fahrenheit) above ambient temperatures.
As a result, the environment cools between 3.6 and 11.3 degrees Celsius (6.5 to 20.3 degrees Fahrenheit), depending on the area (a higher cooling temperature is expected in warmer regions).
Researchers studied the temperature difference between roofs with and without gardens. Throughout the study, different layers of each roof were tested and the effect of temperature on these layers was shown at various times throughout the day. A roof garden has proven to be superior to a roof without a garden in terms of reducing the effects of temperature.
In case rooftop gardens are widely adopted, they are likely to reduce urban heat islands as well as pollution events, heat stress situations, and energy usage. In addition to reducing rain runoff, rooftop plants also resist thermal radiation. By delaying runoff, a roof garden can reduce the rate and volume of runoff.
Urbanization is gradually replacing permeable substrates with impervious constructions, such as buildings and paved roads.
Communities across North America are experiencing issues related to stormwater runoff and combined sewage overflows. In order to reduce peak flow (e.g., the use of rain detention basins), delay (e.g., controlling flow drains on roofs) or hold run-off has become a major solution. Through roof gardens, run-off can be caught and subsequently used by plants to reduce peak flows.
Roof Gardening Advantages
Rooftop gardens offer many advantages, among which are:
For the building owner
- Increase the life of your roof by two or three times
- Reduce the cost of air conditioning
- Reduce winter heating costs
- A tool for managing stormwater
- Increase the value of your home
- Municipalities and governments offer incentives
Increase public image
- Turn unused space into a garden
- Reduce stormwater runoff
- Minimize the urban heat island effect
- Air quality could be improved by reducing smog
- Reduce noise levels
- Reduce the demand for energy
- Enhance beauty
- Provide green spaces
Considering the environment
- Prevent the combined sewer from overflowing
- Reduce the impact of carbon monoxide
- Reduce nitrogen fusion in the rain
- Reduce acid rain’s effects
- Provide habitat for wildlife around the world
Roof Gardening Styles
Based on the type of vegetation on the roof and its care, roof gardens are classified into three main types.
Extensive Roof Gardens
This type of roof garden only requires a thin layer of soil base, so it is very easy to maintain. These gardens can accommodate outbuildings around the house such as garages, garages, roofs, and other outbuildings.
Furthermore, because there are few varieties of plants that can grow on it, it has less aesthetic value. The best plants to grow in this kind of garden are lichen and moss. A variety of surfaces can support lichen growth, including plastic, metal, and glass.
On the other hand, the grass is a small plant that requires fewer nutrients and a high level of soil moisture to thrive.
This roof garden is perfect for humid environments and less expensive in terms of vegetation varieties and design.
Semi-intensive Roof Gardens
A deeper soil layer is needed for this type of roof garden. This encourages plant diversity. This type of garden requires a more sturdy construction due to the vegetation, the heavier weight on the soil, and the need for water retention.
Sedum species (succulent plants) from the lower genus can be used as vegetation in this type of garden. The succulent plants do not require much irrigation since they are dry-climate plants. During prolonged drought conditions, however, the vegetation must be watered more frequently. Wildflowers that do not require maintenance can be grown in such roof gardens.
Intensive Roof Gardens
Plants for such a garden would be similar to those belonging to a backyard garden, such as flowers, shrubs, trees, and a variety of park components.
However, most buildings are unsuitable for intensive roof gardening due to the requirement of huge, stable structures. In addition to standard maintenance requirements, it requires special attention during irrigation.
Roof Garden Maintenance
Maintaining roof gardens is regarded as one of the most significant hurdles to their construction. All types of roof gardens require maintenance, however, so the schedule should be addressed during the design phase. All commercial buildings with roof gardens should have their roofs and gutters inspected at least twice per year.
In the case of a small roof garden, maintenance can be conducted weekly during the summer, whereas more extensive roof gardens might require quarterly or twice-yearly maintenance.
For biodiverse and low-maintenance roofs, drains, gutters, and unwanted vegetation will need to be cleaned once or twice a year.
For extensive sedum roofs, more intensive maintenance strategies would be required, such as fertilizer treatment once a year or three times weeding. As opposed to an intense sedum roof regime, a less intense sedum roof regime will result in more mixed vegetation.
In order to create large roof gardens, wildflower meadows are essential. However, a low-fertility substrate will result in short vegetation that does not require chopping back every year.
Some of the most important things to consider during maintenance are:
- Drain obstructions and unwanted plant growth should be avoided.
- Fertilizers should be used sparingly since high levels of usage can result in excessive nutrients. This could adversely affect water quality.
- In order to prevent fires from spreading, vegetation barriers are crucial.
- As maintenance will take place near the roof edge, fall protection material is necessary. Moreover, it is also necessary to service these fall protection systems at least once per year.
Drawbacks
There are many disadvantages to installation and maintenance. Roofs with these characteristics are more expensive to install, maintain, and require proper irrigation systems.
Conclusion
Roof gardening, sometimes called living roofs or green roofs, offer a number of benefits, including increased agricultural space, aesthetic appeal, and improved air quality. During photosynthesis, plants absorb carbon dioxide from the air and release oxygen that we need to breathe. Roof gardens are one of the best ways to get organic food and take care of the environment as well.
Read More: Benefits Of Microgreens: A Small Wonder Of Nature
Read More: Aquaponics: A Self Sustaining System
