I have been doing design/build for 5 years in central OK (a lot of clay). Just recently I've been having a real problem lately with deodora cedar's, lebanon cedar's & miles high. We have been going through a serious drought here, but all my accounts have irrigation. I've been using these trees for a long time & I've never had a problem before last december. I really don't want to stop using them in my landscapes any advice would be appreciated. When we plant I make sure to ammend the soil with Nature life & apply super thrive.