When it comes to vertical green walls and facades, no two should be exactly alike – each needs to be customised to suit the individual site.
This includes designing the green structure according to weather factors such as light, wind, temperature and rainfall.
Light and shade
As for all gardens, the plants used in green walls and facades will naturally need sunlight. This means that factors such as light intensity, reflection and shading on the site need to be considered.
For example, light intensity is stronger at higher levels as there is greater reflection and fewer impediments to solar radiation. In addition, some buildings will be affected by shadows and shading due to their position in relation to other structures.
These factors will affect the on-site climate, so it’s important to analyse the levels of light and shade on the site across all seasons of the year. Another matter to consider is how these factors could alter due to future nearby developments.
As for sunlight, wind speeds are greater the higher up the building you go. This can also influence temperature and lead to increased risk of plant dehydration at upper levels. There are other factors that affect winds as well, such as downdrafts from nearby tall buildings.
The temperature ranges on the site must be factored in when it comes to plant selection. For example, temperatures tend to be higher at upper than lower levels of the wall due to greater thermal mass and heat gain at height.
Rainfall patterns over the year must be analysed to determine irrigation needs. Where rainfall is not enough to support the vertical green wall or facade, another source of water will be required. This means knowing the water needs of the plant species that will be used.
Installing a vertical garden and keeping it healthy requires a very different set of skills than for ground-based gardens, and always requires a thorough on-site analysis.
This means you should get sound professional advice from experts in vertical green wall installation and maintenance. If you have a green wall or facade project in mind, feel free to get in touch with our team.