The Black Walnut of the Franciscan Ruins

Budapest's biggest black walnut is also the frailest tree on this list, and both facts come from the same survey. FŐKERT, the city's parks company, dated it to around 213 years in its 2020 dendrological study of Margaret Island, which makes it roughly 219 now, and measured its trunk as the thickest black walnut on the island by a wide margin: the runner-up was 119 centimetres smaller around. A national database ranked it second in Hungary for trunk girth. It was probably one of the first trees planted here, in the early 1800s under head gardener Károly Tost, beside the palatine's summer residence. A 1907 newspaper piece describes a walnut in a meadow at the island's centre, 3.5 metres around and 25 metres tall, almost certainly this one. The same 2020 assessment found it hollow and rotting at the trunk and root collar, its crown cut hard back after storm damage and a safety pruning in 2016, and estimated it had about a decade left. That window closes around 2030. It was standing at the last assessment and it is very likely standing now, but the newest evidence here is six years old, so go with your eyes open. It stands by the Franciscan ruins, a hundred metres from the island's oldest yew and 350 from its oldest oak.