Why Hydroponics?

Grodan^®: the Ultimate Growing Medium

• Extensively researched
• Innovative
• Sustainable

Extensively researched

In 2008 we carried out extensive research and trialling alongside several horticultural companies before selecting Grodan^® as our growing medium partners for our patented living wall panel system.

An innovative, sustainable growing medium

Grodan^® is designed with precision growing principles at its heart. A professional horticultural company ourselves, we understand that the vitality and longevity of our living walls depends on such principles. Grodan^® has been awarded a European Ecolabel for sustainability and as a material it is:

• Dimensionally Stable
  We use a dense grade of Grodan^® that was developed for roof gardens in Scandinavia. Tests of original installations show no sign of structural decay after more than 20 years.
• Chemically Inert
  With a zero-cation exchange, no ionic bonding occurs with the nutrients. There is no chance of nutrient lockout or a build-up of salinity to prevent the plants from growing properly.
• Supremely Water Efficient
  Grodan^® acts as a water-retentive sponge. Starting as 95% air, it will hold up to 80% moisture before the material begins to drain. Even when fully saturated, the spun fibres ensure that 15% of the volume is air space to prevent the roots from drowning.

See a selection of our Hydroponic Living Wall projects in our portfolio

Unsuitable Soil

• Easily erodes
• Exhausted nutrients
• Starved plants

The issues with vertically challenged soil

When soil is stacked vertically in a living wall there are three fundamental issues:

• Displacement from erosion
  Soil loss can be exacerbated by windy conditions, resulting in a winnowing effect.
• Exhaustion of the nutrient reserve
  There is no access to rainwater and fresh compost. Nutrients are instead provided by the irrigation system. This leads to:
• The build-up of excess mineral salts
  This build-up, from un-buffered ionic bonding, starves the plant of nutrients.

These problems are not easy to overcome and they become more pronounced with time.

Natural landscapes vs unnatural landscapes

In a horizontal naturally sustainable landscape, soil particles attract water to transfer nutrients to the plants. The soil’s humus content—decayed plant and animal matter, i.e. compost—releases humic acids and humins to buffer the pH levels, as different plants require different levels of acidity. Meanwhile, layers of microorganisms and mycorrhizae perform various specific functions.

The result is an incredibly complex web of self-regulatory systems, which together create a stable environment for life. Gravity plays a huge part in the stability of these systems. Not only does gravity hold them all together, it also ensures the necessary supply of rainwater and fresh compost.

It is simply not possible to replicate this naturally occurring environment in a vertical landscape.

Grodan^® vs Soil

• More durable
• Weather resistant
• Water-efficient

Giving plants everything they need

A plant in soil can expend up to 60% of its energy in the search for nutrients. With hydroponics, plants have everything delivered to them in a precise, controlled manner. Unlike soil, Grodan^® will:

• Be more durable in windy conditions
• Continually provide a more predictable root zone for plants
• Require far less water throughout the year
• Demonstrate a greater resilience in an outage due to its incredible (and predictable) water-retentive quality. Our living walls will last more than 2 weeks without irrigation if necessary
• Last for decades

Living walls are a technically, horticulturally and hydraulically challenging environment, yet achieving robust, thriving plants is simple.