In this day and age of extensive land development, it is not uncommon for an individual house to have little garden space. The demands put on housing, and thus on the land, leads to many habitats being built on a relatively small patch of land.
As a result, gardens and yards do not even enter the heads of planners and designers so it is often up to the homeowner to make the most of what little land he or she has. This is one of the main reasons why biodiverse green roofs have experienced a surge in popularity in the last few years.
Biodiverse green roofs are extremely functional. They are able to trap any rainfall and release it slowly, which aids drainage. This is essential in built up areas. It can also be used to save heat energy with great effect. It will insulate the roof of the house that it is located on and thus keep its inhabitants warm as well as saving them money on their heating bills! Finally, it is a haven for wildlife, and that can help to support natural wildlife against all odds.
Biodiverse green roofs are extremely popular in urban areas and generally take the form of a wild garden with a variety of herbs and grasses, although some individuals do turn them into actual gardens. It is completely up to you, although a lot does largely depend on the type of roof you have and the quality of the structural supports.
Biodiverse Green Roof Or Roof Garden?
Almost any roof can support a biodiverse green roof, but very few can sustain a roof garden because of the sheer weight of the amount of soil that is required in order for the cultivated flowers and grasses to grow.
Green roofs on the other hand actually need very little soil to flourish and can survive almost anywhere. The air quality doesn’t really matter to those plants, but it does to flowering plants because they need cleaner air in order to produce their fruits.
If you are looking for a low maintenance garden to do your bit for the environment or just for something to look out of the window at every morning then a biodiverse roof may just be for you. You only actually have to tend to it once a year, and even then it is only for an hour or two!
You should weed it and evenly spread a slow release fertilizer on the green area, but this should then help establish growth for the following year. As a result of the lack of products needed to tend to the garden, it is also quite cheap to maintain so you are literally getting something for nothing.
Establishing a Green Roof
It is very simple to establish a biodiverse green roof. The initial outlay of both money and time is in fact very little, although it may need tending once a week during the first few months in order to make sure that it does indeed take root and flourish.
The roof must be fully prepared before attempting to establish a biodiverse green roof. It must be effectively sealed so it remains watertight because any leakage would defeat the object of the green roof. After sealer has been applied and left to dry, a fine layer of rockwool must be laid in order to provide a comfortable bed for the soil.
Specialist composts should then be spread evenly over the rock wool, but it should be no more than 1” deep. The compost you use should be able to sustain wild grasses and mosses.
Some seeds may be sprinkled to get the green roof going but it will then actively sustain itself. It really is that simple, but you will get a great sense of satisfaction in return. After all, you are not using that space, so let nature use it for its own ends.
photo of green roof by 416style / CreativeCommons