Growing fruit in groves

Jackie French writes in her book "wilderness garden" that she grows more tropical fruit trees in groves, protected by other trees, like acacias.
They seem to survive freezes of seven degrees under zero.
I have grown acacias here and they needed 3 years to gtow to 2 meters and are still pretty narrow and not very bushy.
Which evergreen very fast growing plants could I use for this? We get -5C in winter. I do not want to use anything pine because they are horrible in a bushfire.

Here are a few evergreen oaks.
http://en.wikipedia.org/wiki/Live_oak

MADRONE (Arbutus menziesii)
OREGON BAY LAUREL (Umbellularia californica)

Then there is cedars.
http://www.burntridgenursery.com/northwestNatives/index_product.asp?dept=86&parent=5




Here are a few tall cold hardy nut trees that you can plant too.
Almond, Black Walnut, Buartnut, Butternut, Chilean Nut, Chestnut, English Walnut, Ginkgo, Heartnut, Hickory, Monkey Puzzle, Pecan, Nut Pine, Oak