Urban ver­ti­cal farm­ing is being dis­cussed more and more inten­sive­ly as part of the trans­for­ma­tion of cities towards resilience and sustainability.

Plant fac­to­ries are being built around the world, green­hous­es are being turned into high-tech pro­duc­tion facil­i­ties and vacant build­ings are being revi­tal­ized for indoor food production.

These projects can be found in high den­si­ty in Japan, Sin­ga­pore and on the east and west coasts of the Unit­ed States.

The inven­tion though as inno­v­a­tive cul­ti­va­tion- and pro­duc­tion meth­ods goes back for more than a half a cen­tu­ry when the com­pa­ny Ruth­n­er Indus­trieller Pflanzen­bau (Ruth­n­er IP) set up its first pro­to­types and named them “Phy­to­tow­ers”.

After the real­iza­tion of numer­ous ver­ti­cal farms in Aus­tria, Europe, over­seas and Asia, the com­pa­ny Ruth­n­er IP came to a rapid end with the death of the inven­tor Oth­mar Ruth­n­er. A few years ago, the ver­ti­cal farm insti­tute made con­tact with the then man­ag­ing direc­tor and son of Oth­mar Ruth­n­er, Oswald, and began to process and dig­i­tize the holdings.

By repro­cess­ing them, the under­stand­ing of the chal­lenges of indoor food pro­duc­tion can be increased, lessons can be learned from “tri­al and error” and knowl­edge can be trans­ferred into the 21st century.

Sen­a­tor Dipl. Ing. Oth­mar Ruth­n­er was born in Vien­na on 26 Octo­ber 1912. He attend­ed the Fed­er­al Teach­ing and Research Insti­tute for the Chem­i­cal Indus­try before attend­ing the Vien­na Uni­ver­si­ty of Tech­nol­o­gy for four years as an asso­ciate stu­dent. He reg­is­tered patents for sev­er­al met­al process­es at an ear­ly stage.

Dur­ing his stud­ies, he was already plant man­ag­er at Böh­ler Ybb­sstahlw­erke and head of the research and test­ing cen­tre. After the war, he found­ed his first com­pa­ny for the devel­op­ment of elec­tro­chem­i­cal-met­al­lur­gi­cal indus­tri­al plants in Vienna.

He rapid­ly expand­ed the com­pa­ny Ruth­n­er-Stahlbau, found­ed in 1952, and reg­is­tered numer­ous patents for indus­tri­al plant con­struc­tion in the mid-1950s. In 1960, he was made an hon­orary sen­a­tor of the Tech­ni­cal University.

His son, Dipl. Ing. Oswald Ruth­n­er, born in 1939, worked as man­ag­ing direc­tor of the Ruth­n­er com­pa­ny from the mid-1950s and shaped and accom­pa­nied the busi­ness devel­op­ment and inter­na­tion­al­i­sa­tion of the Ruth­n­er tow­ers. The death of the inven­tor in the late 1980s marked the end of the com­pa­ny and the fur­ther devel­op­ment of the idea of devel­op­ing new build­ing typologies.

The con­cept of the phytotower

A phy­to­tow­er is a phy­totech­no­log­i­cal process for the con­tin­u­ous pro­duc­tion of plant raw mate­ri­als. It is a ver­ti­cal cul­ti­va­tion method in which plants are grown in sev­er­al lay­ers on top of each oth­er. This method utilis­es space more effi­cient­ly and enables a high­er yield rate on a small­er area com­pared to tra­di­tion­al cul­ti­va­tion methods.

Aspects of functionality

1. ver­ti­cal arrange­ment: The phy­to­tow­er utilis­es a ver­ti­cal struc­ture in which plants are grown in sev­er­al lev­els on top of each oth­er. This max­imis­es the use of avail­able space and enables a high­er plant density.
2. con­tin­u­ous pro­duc­tion: The sys­tem is designed to enable con­tin­u­ous pro­duc­tion. This means that plants in dif­fer­ent stages of growth are present at the same time, allow­ing for a con­stant harvest.
3. automa­tion and con­trol: The phy­to­tow­er is equipped with auto­mat­ed sys­tems that con­trol irri­ga­tion, nutri­ent sup­ply and light­ing. These sys­tems ensure that the plants have opti­mal grow­ing conditions.
4. effi­cient use of resources: The ver­ti­cal arrange­ment and auto­mat­ed sys­tems opti­mise the use of water, nutri­ents and ener­gy. This leads to a more effi­cient use of resources com­pared to tra­di­tion­al cul­ti­va­tion methods.
5. envi­ron­men­tal­ly friend­ly: the phy­to­tow­er reduces the need for agri­cul­tur­al land and min­imis­es the use of pes­ti­cides and her­bi­cides, result­ing in more envi­ron­men­tal­ly friend­ly production.
6. adapt­abil­i­ty: The sys­tem can be adapt­ed to dif­fer­ent plant species and vari­eties, mak­ing it ver­sa­tile and flexible.

These aspects make the phy­to­tow­er a promis­ing tech­nol­o­gy for the sus­tain­able and effi­cient pro­duc­tion of plant raw materials.