Oh and don't let the roots freeze if you are watering them! Only leave them unprotected if they are well neglected and well drained, try and forget about them until early Spring!!!

I know dealbatas can tolerate occasional overnight -7 - -8 degrees in Adelaide and Mount Gambia, South Australia but then this isn't prolonged and its usually above zero during the day and they also have a long, hot summer to build up their sugar-alcohol levels so they are probably better equiped to supercool and avoid freeze damage freeze going into the winter.

From what I gather we got a prolonged frost of -11 degrees+ to -1 degrees around here (Salisbury, Wiltshire) that lasted for over a week in early January.

This snow isn't even touching them now but! They are even looking slightly heathier than they did a few weeks ago.

I was doing some planting in Virginia, USA over the winter as a favour and it was the only oppotunity I had to plant all year. Pot grown Pittosporum tobira dwarfs, Raphiolepsis indica and huge Lagerstromia 'Muskogee' transplants, Liriope muscari and Mondo grass (Liriope japonicus) liners. It was 5 degrees when I planted and everything was frozen from the night before when it got down to -11 degrees which is unusally low for over there, even though I had made an effort to protect them. I had to dethaw the plants by soaking them in a bin of water before planting and mulching! 1 month later and no sign of any damage so I'm told. But remember they were grown in a climate with a very hot and humid summer however!

Wish we had hot enough summers to get Crepe Myrtles to flower over here, all we get is rain, sleet, fog and low cloudcover all year!!

Let us know how your Acacias get on, with this thread.