Acting head gardener Ian Bawcutt said: "We're doing a big clear up at the moment. The tornado hit swathes of the arboretum. It definitely caused a lot of destruction. We've lost 40-50 trees plus a lot of crowns of trees. A lot have split and are going to be useless. We won't know the worst for a few weeks.
"Hillier Nurseries is close to us and missed the worst of it — it was that localised.
"All our trees are important but one we lost is a Judas tree near the heather garden that was split in two. Things like this find weaknesses in your trees. It is nature's way of showing you that there are problems in trees."
Subscribe to Horticulture Week for more news, more in-depth features and more technical and market info.