Growing Trees for the Back Yard

We have a lot of tall beautiful trees in our front yard and we want to extend our forest a bit in the back yard. So we have bought about three dozen seedling trees, mostly the pine-like casuarinas that the black cockatoos love, to transplant into the back yard. These have been growing for about 6 weeks. I will plant them in the fall. Our grevilleas (below) are also in full bloom after recent rains...