Borderline hardy tree that flowers in winter...

We grow several shrubs and trees here at Langdale that can be classified as borderline hardy. Generally they are in RHS hardiness rating H3 (-5 to 1) or H4 (-10 to -5). From time to time we do get asked why we grow them and is it all worth the risk?

Acacia baileyana 'Purpurea' is one such at H3.

For many years we grew it in a pot, protecting it when the weather turned frosty in winter. Then it got to the stage where it really needed to be planted out in the soil, so we found a relatively sheltered spot for it, still protecting it with a fleece covering in winter when necessary.

These days we don't protect it at all in winter - for starters it is now just too big to do so, but also we think it has now reached a maturity and its roots have found their way to a depth where it no longer needs it. And this is our reward - a tree with beautiful purple tinged foliage throughout the year which flowers like this in winter.

My question is, why wouldn't you?