Giant redwood

The giant redwood is a plant species that deserves an entry in the Guinness Book of Records. Not only do the trees grow to be huge, but in their natural habitat in California, some individuals are more than 3,000 years old.

Although the giant redwoods in the Botanical Garden are still comparatively young, their survival is at risk due to a fungal disease. Vienna's increasingly hot urban climate does not offer the sequoias optimal conditions. They miss the cool, humid weather conditions of their native habitat. This makes them more susceptible to diseases and pests. Over the years, the three specimens in group 23 have shown symptoms of disease – the crowns have become increasingly thinned out and the trees have been significantly weakened.

The disease is caused by the microfungus Bothryosphaeria dothidea, which has already been observed in several locations on redwood trees in eastern Austria. In addition, our trees have been attacked by the thuja bark beetle, which originates from southern Europe. Two specimens had to be felled in recent years. A five-metre-high stump was left on one of the two specimens, which remains as valuable deadwood for insects and birds.