Taunton Deane’s perennial kale features in my book. Sadly it is the only surviving perennial kale in the UK. Here are a few pictures of it taken on a visit on 6th July 2011! I was blown away by this amazing garden which features several places in my book!
http://www.edimentals.com/pictures/index.php?/category/26
I guess these are relatively young plants as my FB friend, Alex Prendergast, posted a picture of a plant at Knightshayes which is perhaps 2.5m high in the Edimentals forum: https://www.facebook.com/photo.php?fbid=10153759815488496&set=pcb.999391683405266&type=1&theater