wrote in message
...
About 10 years ago my neighbor planted two rows (staggered) of
evergreens to act as a privacy barrier.

Now the trees are getting pretty big and he is concerned that they
might choke each other out and die.

The self thinning rule of ecology will take hold. Yes some may die but they
will be specifically targeted and when they die their mass will be recycled
into the soil to increase the health of the group along the way. If you
wanted to choose ones to cut a SHIGOMETER would help. Also the wood from
the trees cut could be given soil contact and the brushy stuff could be made
in brush piles for wildlife.


He could remove one of the rows
but the "insides" of the trees don't have any healthy growth since not
much light gets in there.

Questions a

- Is it possible that the trees could choke each other out or can they
survive close to each other?

No, they are better in a group.



- If he does remove a row will the previously unexposed side of the
tree generate new growth or will the just look nasty forever.

Depends on the species, environment and genetics. The trees will do better
in groups. Not really a thing as too close together. have you ever seen a
kissing tree?

When cutting trees in a group or tree farming there are some points to take
into consideration:
http://www.treedictionary.com/DICT20...nce/index.html


A good source of tree information based on a thorough understanding of tree
biology is he www.shigoandtrees.com

--
Sincerely,
John A. Keslick, Jr.
Consulting Tree Biologist
http://home.ccil.org/~treeman
and www.treedictionary.com
Beware of so-called tree experts who do not understand tree biology.
Storms, fires, floods, earthquakes, and volcanic eruptions keep reminding us
that we are not the boss.
Some people will buy products they do not understand and not buy books that
will give them understanding.