Alive, dead, and inanimate. These are the categories you learn in school: plants, animals and people are alive, until they are dead; and glass, stone or concrete are inanimate, having never lived (at least not in a similar capacity). We can use living and dead things to feed ourselves and keep us warm. We can use inanimate materials to build things. It’s relatively easy to build a tent from branches and animal skins or a simple house from wood and straw. But dead materials are in that vulnerable state between living and vanishing: too wet and they rot, too dry and they can catch fire. So inanimate materials would have been better. Glass, stone and concrete are – if stacked properly – safe and permanent. Stone and concrete were the material of choice for important people and for security or stability where necessary. Plants were considered purely as useful for food and medicine.

 

One had to be very wealthy to be able to afford using land for something other than cultivation. Lawns as we know them today – austere planes of greenery with no purpose – were only invented when garden-architect André Le Nôtre designed a small tapis vert in 1662 for the gardens of Versailles. This was confirmation of the king's extreme wealth. Motifs inspired by nature were certainly always part of the vocabulary of architecture and interior design. However, these were artful interpretations of plants and flowers, not living greenery.

 

It was only once sailors and adventurers returned to Europe from the colonies with hitherto unknown curiosities that living plants started to move indoors. Keeping and displaying a tropical plant in the parlour became the height of fashion. With the Industrial Revolution, increasingly filthy cities, and a diminished relationship with nature, the popularity of the plant as decorative interior element grew. Joseph Paxton's giant greenhouse for the Great Exhibition of 1851 in London, the Crystal Palace,  attracted huge crowds. And in the meantime, machine-made reproductions of valued furniture were exhuberantly combined with plants and decorative paraphernalia in overcrowded sitting rooms. An accumulation of so much poor taste spawned alternative directions, simultaneously between 1890 and 1914: the Art Nouveau, the Arts and Crafts, and the Jugendstil. Each style employed plant-based themes and excelled in craftsmanship and elegance.

 

Yet they didn’t last. The world wars put an end to the ability of old families to invest in craftsmanship in architecture, art and decoration. The demand for clean, healthy, light-filled architecture was met by Modernism. Ornamentation was renounced, though greenery remained important. Small and easy-to-care-for potted plants became part of simple home interiors, and the villas gained inner gardens integrated with interiors. There are some beautiful examples of this in the architecture of Berthold Lubetkin, Hans Scharoun, Frank Lloyd Wright and John Lautner. After this, the fashion of integrating living plants with architecture came and went. When the cities and the air became cleaner, the plants were left to die.

 

But then came the vertical garden of Musée du quai Branly by Jean Nouvel in 2006. Since then, many roof and façade gardens have been built, culminating in Milan’s Bosco Verticale, a structure comparable to the gardens of Versailles in their beauty, expense, and maintenance. The green theme is once again peaking and living plants are being installed everywhere into, onto, and around architecture in the most inventive ways.

 

Inescapably, ‘living’ also means maintenance. A living plant needs to be nourished and protected against diseases. Even a much-cherished plant can die. We are not very good at taking care of our surroundings and giving it the attention it deserves. Perhaps we’ll learn through our plants that we should also look after our buildings: achieving sustainability through the maintenance of quality. Now that the prohibition on ornamentation has been lifted, we may once again enjoy flowers and plant-like motifs on our wallpaper and upholstery. In the unlikely event that we are unsuccessful in our care responsibilities, we can always fall back on the precept that inanimate is still the safest bet.