Design / Process
Each vertical garden is given a unique design and selection of species. The composition of plants takes in consideration the specific environment where it will be built, such as the local- and micro climate, sun exposure and the surrounding context. The aim is to create a one of a kind and site-specific garden that stands beautiful through all the seasons of the year.
A well executed design is also a way to minimize the future maintenance demand of the garden. A plant's growth habit, size and behavior on a vertical surface is important knowledge for making the right combination of species, in order to keep the competition between plants at a healthy level. Choosing the right plant for the right place makes sense for any garden, but maybe even more so in a vertical garden.
As ornamental objects, not only can the beauty of plants be fascinating, but also the fact that they are alive and always changing. Much work is put into the aesthetic result of the gardens, and part of that is to develop this attracting sensation of life and unpredictability that plants bring within themselves. For the overall design a lot of inspiration is taken from natural shapes and environments where these type of plants have their origin, and in the smaller scale each species is given a context where it can develop it's characteristics. All together creating a unique garden with much content, surprise and variation.
A vertical garden can be installed in almost any location and as a living material, the potential of integrating plants in our urban environments is interesting. Places never though of as possible could be inhabited by plants, like subway stations or other intensely frequented places where horizontal space is difficult to spare.
The supporting structure consists of a 10 mm PVC-board mounted on a stud work. The solid PVC-board is sealed at joints, and an air gap between the board and the wall behind assure a double protection against moisture. On top of the board, a multi-layered, synthetic and highly absorbent felt surface is attached. It gives an even distribution of water over the surface and provides mechanical support for the plants as they grow attached to the felt. A cut is made in the outer felt layer and the plants inserted in between. As a soilless surface, the construction is very light – less than 25 kg/m2. Including plants, but depending of what species that are used, the average surface depth is increased with 200-500 mm.
The irrigation system is designed to minimize water consumption. It consists of an automation-unit with equipment for control of nutrient injection and irrigation cycles. When a surface has a variation of sun exposures, the irrigation is divided into segments in order to program it specifically for each part. Within the multi-layered felt surface a drip-tube is integrated. Water consumption varies with heat and sun exposure, but compared to normal green spaces or a lawn, the consumption is normally lower. It averages between 2-5 l/m2/day.
Direct sunlight can deliver over 100.000 lux whereas the average light level in an office is around 300-500 lux. Even if the least light demanding species are used, artificial light is normally necessary indoor. A few species will stay fine at 900 lux, but a slightly increased level at some parts of the surface will broaden the variation of species that can be used. An artificially illuminated surface has shifting light levels, due to the fact that light reduces with the square of the distance from the light source. Some areas might have 3.000 lux and others 900 lux. The plant design is made with this in mind, taking advantage of the higher levels for more demanding and interesting species.
Not only is artificial light necessary for the plants survival and growth, but it also makes the garden more beautiful as it brings out colors and textures of flowers and leaves. A suitable light source is the metal halide. It produces the essential wave-lengths that plants need and is an energy-saving and cost-efficient alternative. Through an initial computer simulation, a study is made to calculate the required number and model of armatures. Finally, the levels are measured on location to fine-tune the setup.
As the supply of the basic needs of plants (light, water and nutrients) are automated, not only does this make for unusually healthy plants - it highly reduces maintenance demand and makes the vertical garden possible to use on high buildings or other places where accessibility is limited.
The garden is designed so that the plants´ natural growth habit is given space, and for different species to have a dynamic co-habitat with adjacent species. During a year, the garden will profit from pruning approximately 1-2 times per year. All plants that are used are perennial, but as the years go by, a few will have to be replaced. These maintenance measures will ensure a long term lush and attractive garden.
The Realization of a Project
The initial work includes studies of the local climate and the future location to see what site specific factors there are to consider. This will give the limits for what plants that may be used and is important information in the following survey of nursery stock from those nurseries, foreign or local, that can deliver to the location.
As the general conditions are defined, the design plan is developed in order to attain the desired character. It is during the design phase that the final selection of species is made, based on physical conditions, aesthetic preferences and availability.
At the construction site, the first step is to set up the supporting structure and make necessary preparations for the irrigation. When the technical system is completed with the mounting of the felt and the integrated drip-tube - the surface is ready for plantation. During the whole process a dialogue is kept with the architect and client in order to achieve the desired result.