Home Improvement Questions? Ask a Handyman for Answers
Those probably suffered from humid air and hot temperature. The blue come from a waxy coating they produce to protect from dry winter air, they have very few defence from humid air.Most tree are best planted in early spring or in fall when in dormency.
You may also got symptome of spruce decline:http://msue.anr.msu.edu/news/what_is_spruce_decline_and_what_should_you_do_about_it
The only thing i know to help them is to prune lower limb to allow a dry area and burn those limb to kill any spores. The place you plant the trees is important, they need to be in a position where they can dry fast after a rain (from wind and sun).
As the tree is closely related to white spruce (essencially a white spruce adapted to dry condition), look at this guide and tell me if you see similarity with what you have:http://files.dnr.state.mn.us/assistance/backyard/treecare/forest_health/whitesprucediagnosis.pdf
If it was frost the tree may start a new bud from the stem at some place (lower than the last year new growth) and you could straithen this into a new up leader and cut the dead leader at one point. On conifer it is sometime possible to trigger faster such a new bud by doing a very fine notch in the bark.It will greatly impact the gowth and if you want a big tree, plating one new might be faster than waiting for a recover, if you do, plant in early spring or late fall, not in summer. That type of tree is adapted to your area but some nursery have tree selected for their blueness instead of their hardiness, so a native tree will always beat a nursery one.
$600 each! how tall where they when they planted them?
That is tall. They must really have badly adapted as he mentioned (transplant shock). It take quite a bit of root ball to allow such a big tree to survive. It also require a long period of constant water drip watering until it make a new root system that extand far enough from that root ball.
One problem that can happen in such a transplant is if the local dirt contain clay while the tree root ball does not and have a softer content. Then the water can pool in there and cause root rot (that spruce is not tolerant to stagnant water like black spruce it). Also, Aspen are big water sucker. On open area where i have some cluster of aspen the soil become almost desertic on south side. It is possible that because they re-grew root faster than spuce that they monopolized the water if you planted them closeby.