I'd recommend metal fencing for the apple tree, lilac, and the Norway spruce. You can get a roll at home depot or probably other similar stores. Go with a 3 or 4 foot height. I'll attach a picture of this in the next post. The metal cage will allow the plants to develop big and wide branching structures, which is important for these 3 species. For the oak and maple you could use either the metal fencing or tree tubes. See the recent MWL blog about protecting newly planted trees. Using tree tubes will result in plants that do not have branches below the top of the tree tube, which is just fine for oaks and maples. Please feel free to post pictures of your plants (with or without protection)! And feel free to follow-up with any questions.

This pear tree was about 4 foot tall when planted. It was protected with 4 foot tall metal cage (from a roll, bought from home depot). The diameter of the caged area is about 2 feet. But I'd recommend going a bit larger. Say up to 4 feet in diameter. [attachment]metalcage-peartree.JPG[/attachment]

Here's a chestnut tree that was protected by a metal cage. The tree was 2 feet tall when planted, and the metal cage is 4 feet tall. A tree tube would have worked too, but the chestnut would not be branching out as low to the ground as it is now. [attachment]metalcage-chestnuttree.JPG[/attachment]

You can also fence multiple plants into the same area. This landowner in Westchester enclosed 4 shrubs in a single area. [attachment]fencedareawithshrubs.JPG[/attachment]