The 15 Dicksonia antarctica and Dicksonia fibrosa tree ferns – which are each about 70 years old – have already caused a few sleepless nights for the team involved in the World Vision Garden’s build. The ferns struggle to survive if it’s colder than minus five degrees and, at one point during the winter, temperatures dropped to minus 10. Luckily though new fronds are starting to unfurl, and the ferns are getting lots of care, attention and dousing in water from the best in the business – such as Hillier Nurseries, who are also bringing some on for the 2012 Olympic Village. Our designers – John Warland and Sim Flemons – are now hoping for a warm few weeks to give the trees the humid growing conditions they like, before they move them outside to acclimatise to life away from a greenhouse. Once they’re in the open, their fronds will droop slightly – and it’s important to get this slump well out of the way before they appear on Main Avenue in just four weeks time. Our garden design creates a space of shelter and nurture, representing the protective environment that the international children’s charity offers vulnerable children living in the world’s hardest places.www.worldvision.org.uk/rhs