Fencing off a whole orchard with something that is high enough that deer can't jump over is pretty expensive. I use the 4-5' high circle around the tree method.
The deer won't jump into the small circle surrounding the tree.
My sisters live in Colorado and tell me the Elk just can't be stopped. They'll push over any fence and are protected so you can't shoot them.
I was at a tree nursery today and they sold a nitrogen fertilizer called Milorganite:
They put it in small cotton bags and hang one bag from each newly planted tree. The Milorganite has a strong smell and I suppose that keeps the deer away.
Note that this grower has thousands of trees and has been there for several generations, so I figure they know what they are doing.
Here are the bags they use:
The bags need to be changed after 2-3 months.
I bought a bag of the Milorganite and 100 bags so I'll report back at the end of the season if it works.
The commercial grower also said that LEAD (specifically .30/06) is the best deterrent. I prefer 308, but everyone has their personal preferences.