The north­ern­most olive grove in the world

What is believed to be the north­ern­most olive grove in the world, belongs to the garden nursery of Gartenhof Becker, and was created in coop­er­a­tion with a German olive dealer. Its olive trees, which were initially only planted for deco­ra­tive purposes, were always full of olives in autumn.

“That fasci­nated me,” recalls gardening and tree nursery master Michael Becker. The olive dealer not only inspired him to create his own olive grove, but also brought him the first plants. In 2005, Becker planted the first two-year-old trees as an exper­i­ment, with a lot of love for the Mediter­ranean trees. “Olives are just beau­tiful, with their silvery leaves. And I also simply love olives and olive oil,” he enthuses.

Frost hardy but not winter hardy

The first harvest was realised in 2008 – which is not unusual, because olives start producing after five years. “That was a very happy moment,” says Becker. However, this period of elation was followed by a really cold winter. The tree nursery team wrapped 50 trees in fleece. And then they gave up. ”This was horrible work,” says Becker. In the end, the unwrapped trees were looking better than the wrapped ones. Only the Italian variety, Lecchino stood out with its hardi­ness that winter. This variety toler­ates temper­a­tures of minus 15°C without any prob­lems. But it is prob­lem­atic when the temper­a­ture reaches -20°C. “Olives are not winter hardy, they are frost-resis­tant,” explains Becker.

Because so many trees had been damaged by the frost, Becker completely redesigned the growing system in 2009. The young trees were started with only three to four branches and a trunk with the thick­ness of a finger. The spec­i­mens are now 13 years old and around two-and-a-half metres high. This second gener­a­tion of Cologne olive trees has so far been spared from major losses due to frost and is devel­oping splen­didly.

These trees have also with­stood extreme weather events – for example, days on which the temper­a­ture fell from +10 to -8°C, only to rise again to 14°C the next day. “The trees didn’t like that, and then in March, they had no leaves,” reports Becker. However, after we performed severe pruning, the trees recov­ered quickly.

A wind sensi­tive culture

In his expe­ri­ence, Becker says that olive trees need wind protec­tion, rather than frost protec­tion. That is why the trees are now supported by a thick pole and trimmed to a height of 2metres.

Surpris­ingly, these olive trees grow well on the fertile, slightly acidic loess loam of the Cologne Bay. They are usually found in the Mediter­ranean region, on extremely poor, calcareous soils. “I never would have thought that they would grow so crazily here. I was fasci­nated,” says Becker.

Unsur­pris­ingly, Becker’s unusual success attracted imita­tors. Some have tried to grow olives as well, but none of these efforts have been successful. “The Bay of Cologne is the region with the mildest winters in Germany,” says Becker, explaining his success.

An olive grove as a visitor magnet

A busi­ness model has not been devel­oped yet for the olives. So far they have only served as a magnet for visi­tors. Never­the­less, the olive grove has proven its worth. At its annual Olive Festival, the Gartenhof Becker now welcomes around 120 exhibitors and 10,000 visi­tors.

The fruits in the Bay of Cologne only ripen in November, whereas in Spain, harvest is complete in September. Becker’s good harvest in 2020 caused a sensa­tion, with 300kg of olives gath­ered, i.e. a little more than 2.5kg per tree. In the news­pa­pers, arti­cles appeared about the first German olive oil. Yet from 180kg of olives, only 3.5 litres of oil could be pressed with a press purchased from Italy – when this should have been at least 60 litres. “I started receiving enquiries straight away. But I was reluc­tant to give away 3.5 litres of olive oil,” Becker recalls with a smile. Becker has come a good deal closer to his dream of producing “Olio di Colonia”. But there is still a long way to go before Cologne olive oil can be sold.