after fertilizing, why did crape myrtle soon lose all its leaves

Asked September 22, 2015, 3:01 PM EDT

I just planted 2 new crape myrtles. I had 2 other crapes that are 2 years old. I ferilized them all with weed killer included. I put down 4lbs/1 inch trunk diameter. Within a week all leaves turned bown-yellow and dropped. What happened? What can I do now?

Travis County Texas

1 Response

Your soils are probably already high in salts, adding fertilizer increases the salt content causing a "burning" of the feeder roots. The leaves will first become scorched and progress to brown and eventually fall off .Watering to dilute the salt will help. The plant may recover, depending on the severity of the damage. you may have to wait till next season and hope for new growth from the base of the plant. It is not recommended to fertilize newly planted trees.