We know someone who had bare root seedling trees machine planted in 2007 in late spring/early summer by a commercial planter. The trees were planted around June 11th. The landowner wanted to wait until his hay was cut, so he held off the planter till June. The severe drought conditions started at that time. Not a 1/2 of rain fell in the next 5 weeks. The ground was hot and dry already at planting time. An outside observer suggested that the evergreen trees would have lived if they had been "acclimated" or "warmed up" before planting. He said taking them from a cooler and planting them that day killed them, not the hot, bone dry conditions at the time, and what followed for weeks. I know the planter, he wanted to plant much earlier, but the owner made him wait. The owner agrees that he should have let him plant much earlier. It was only a few hundred trees so it is not a big deal, just a matter of getting to the truth about what really killed the trees. No one thinks it was herbicide, since it was used sparingly. We had never heard of letting trees warming up, it was always a case of keeping them cool and moist.