Vegetative or ground covers; One of the main problems of cities, is the shortage or lack of green areas, which do not grow in unison with the growth of the city itself.
What are ground covers?
The plant covers, are an extensive landscaping by covering free surfaces for it. Likewise , Vertical Gardens do the same with walls that will be covered in green.
This type of cover is used especially where, in addition to light weight, low maintenance costs are also required.
Sedum species are the most suitable and provide a low maintenance landscaping, on vacant surfaces.
The different species of Sedum tapizantes, have their main flowering in the early summer, predominating floral colors yellow and red / white.
These colors are also combined with the red colorations of the leaves, especially in autumn and is done either by planting shoots or with small rootballs.
Green covers, or extensive green covers, include coverings with vegetation that spread easily and can be developed and maintained for longer.
In general terms, extensive plant covers have a substrate thickness of between 4 cm and 15 cm and a weight per m2 of 30 kg to 220 kg.
For the Sedum , they tend to be between around 30 kg per m2.
The fact of the incorporation of vegetal roofs in the buildings, is a good measure of the sustainability applied to the new construction or rehabilitation of existing buildings.
It provides great economic, environmental and ecological advantages, while improving the energy balance of buildings.
So much so, that in the city of Toronto, was legislated so that buildings of more than 2,000 m2, must have between 20% and 60% of ground or green roof covers.
We also find significant performances in Switzerland and in Copenhagen.
Benefits of the plant ground covers.
- The vegetal covers, mean a greater protection to the waterproofing of the roof.
- They reduce the impact of UV radiation, which ages the materials and reduces the influence of high temperatures on the roofing materials.
- They protect against physical phenomena, such as hail, wind, rain, vandalism, fireworks, etc.
- They reduce the environmental CO2.
- It is estimated that a roof of 1m2 can absorb 5 kg of CO2 per year.
- Otherwise, “1 m2 of vegetation cover can absorb the same amount of CO2, which would emit a normal vehicle in a route of 80 km” .
- It isolates acoustically, reducing reflection by up to 3 dB and insulation by 8 dB.
- Plant covers, prevent thermal overheating in summer, as well as heat loss in winter, isolating the cover
- They reduce the heat island effects that buildings create.
- This difference can be up to 10ºC, due to the effect of transpiration and humidification of the air due to the evaporation of water in the Sedum plantations.
- Retention of rainwater.
- Rainwater runoff is reduced, so that a large amount is used in the plantations themselves and in the way they are placed on the roofs of buildings.
- Depuration of rainwater.
- Through the natural biofiltration, controlling that the toxins reach the water currents.
- The vegetal covers, retain heavy metals that remain in the substrate.
- Reduces the levels of air pollution.
- Green ground covers are able to filter 0.2 kg of dust into small particles.
Other benefits provided by green roofs:
- Creation of small habitats for the city’s own fauna.
- It shelters many insects and shelters and feeds many birds and bats, which can haunt and take refuge in the plantations.
- Contribute to biodiversity, for fauna
- Plant ground covers, improve the urban landscape.
- Increase the “green” of the cities, the living comfort of neighbors and other inhabitants contributes, based on all the previous improvements.
- Greater durability of the covers.
- Covers treated as plant covers triple the expected durability.
- They suppose a good protection against the temperatures, UV radiation, mechanical damages, etc.
- Plant covers have great aesthetic benefits.
- Soften and color the hardness of the city, its gray colors.
Types of plant covers.
Extensive plant covers :
They have shallow soils, from 8 cm to 15 cm.
It is especially suitable for planting, sedum , moss, aromatic, grass, etc.
It is a light cover and does not need irrigation system, except periods of long drought.
Intensive plant coverings:
The soil layer is thicker, greater than 15 cm. there you can plant shrubs, small trees, etc.
Requires, irrigation system and involves maintenance.
Why Sedum is very suitable for plant covers?
Of all the previously mentioned, it is indicated by the following:
- Sedum is suitable for plant ground cover because they have very shallow roots, adapted to the shallow depth of the substrate.
- They are resistant to drought.
- Plant covers, need little irrigation, few nutrients and are low maintenance.
- They are very resistant to pests and insects
- As succulents, they are very adaptable to periods of drought and have great power of recovery as soon as they are watered or the rain falls.
The revolution of green roofs or green roofs is not limited to buildings.
As a novel case and that could surprise more than one, is the installation of plant covers, on the roofs of urban buses in cities.
The data obtained by these mobile gardens are a reduction of 3.5 ° C in the middle of summer, due to the high insulation provided by green roofs.
As well as the reduction in the energy consumption of the AA devices.
Plant covers acts as a CO2 sink for the vehicle, helping to regenerate the polluted urban air.