Question
Jim, about 7 years ago I planted some young cedars and pines along the front of our property.  When I planted them, they were all around 3 or 4 feet tall and very, very thin.  I never knew they'd grow so fast!  Now they're all well over 10 feet tall but very close to one another.   

They make a great barrier (dust filter) between us and the gravel road but they look congested.  Is it ok to leave them this way or should I consider thinning them out?  Is it possible to safely separate these trees or is it too late?  It would be a shame to destroy some of them.  I was told that moving conifers is best done in the spring or fall.  Is this true?  

Answer
Moving trees 10 feet tall is quite a job and the success rate goes down as the tree size goes up. I would leave them as is for three to five more years and then thin out every other one. This will give you the barrier wanted and the "congestion" will not hurt the trees in the short run.