Last fall we planted 75 little thuja trees (see post and picture here) along our property line to eventually form a privacy screen to block out ugly junkyard neighbor. The plants went kind of dormant (as expected) during the winter but when spring came they came back to life and have really been growing. They've about doubled or more in size. That is until last week. Suddenly, about 4 of them just pretty much upped and died! DH did some research on what might be the problem. I thought maybe over-watering (he does that) but thought that would be a slower death rather than just in a few days going from nice and green to brown. He thought it was spider mites.
The kids took one of the plants to a garden/nursery that was recommended to help figure out the problem and it turns out it's a problem with the roots because we used potting soil to put in the holes when we planted them. Apparently that is not good for evergreens! Now that they are trying to grow grow grow the potting soil holds too much water and the roots ball up and turn black and kills the tree.
So yesterday DH and the kids (gosh I'm glad I was at work - haha!) literally had to dig up 75 trees and replant them! They had to use just "regular" old dirt and also bought several items recommended by the garden expert - $117 later! Ouch. But, I guess it's worth it to try and save all those trees. There was some kind of liquid and powder to mix together (that from the looks of it will be enough to last our lifetime!) to dip the roots in before replanting. Then there was some kind of fertilizer to spread around the trees (but not touch the trunks) after replanting. So, we are all keeping our fingers crossed that we fixed the problem in time and the trees will now be able to grow healthily.