Grevilleas should go in now, while the ground is still warm. Not sure
about frosts, but I'd check with the local nursery as to what would suit
the area. I'd protect from cold winds. Get your husband to show some
respect or place some rocks around the perimeter - not too close to
the trunk of course. They need water kept up to them for the first
couple of years (not too much) .. same for the banksia ( http://
asgap.org.au/b-eri.html) try banksia ericifolia with the most stunning
red floweers up to 1.5 mtrs. They flower in winter so the nectar
feeding birds have food then, and then the grevilleas for feeding
almost all year.. I agree the superb is fabulous (though i do go mad
occasionally and hack a few branches back. ned kelly, Honey gem,
Moonlight are all stunning depending on the height. We moved to an
acre and took out every single feral plant (bar a few roses my husband
needed for his Englishness, and in only five years the garden looks
wonderful and takes far less care and water. And don't thinkj Aussie
plants don't make a colourful garden.. they're more subtle once you
start delving into the variety. Grafted grevilleas may be the thing for
you in a cold area.. they are very strong. I've been sick lately, but if you
are interested will potobucket some images of the garden when I can
work it out again. The native bird population has increased enormously
too!